BC 
 
 THE 
 
 THINKING 
 
 PROCESS 
 
 "** 
 
 
 NATHAN A. HARVEY 
 
 STATE NORMAL COLLEGE 
 YPSILANTI, MICHIGAN 
 
 J 
 
Class i 
 
 Book 
 
 Copyright^ . 
 
 COPYRIGHT DEPOSIT 
 
The Thinking Process 
 
 NATHAN A. HARVEY 
 
 STATE NORMAL COLLEGE 
 YPSILANTI, MICHIGAN 
 
 Copyright 1910 
 NATHAN A. HARVEY 
 

TABLE OF CONTENTS 
 
 CHAPTER 
 
 PAGE 
 
 I. Laws of Association .... 
 
 7 
 
 II. Formation of the General Abstract Notion 
 
 20 
 
 III. Properties of the General Abstract Notion 
 
 34 
 
 IV. Judgment ...... 
 
 42 
 
 V. The Syllogism 
 
 51 
 
 VI. Deductive and Inductive Reasoning 
 
 62 
 
 VII. Other Forms of Reasoning 
 
 70 
 
 VIII. The Thinking Process .... 
 
 82 
 
©GU8568I© 
 
PREFACE 
 
 The present chapters are intended to furnish to 
 students of elementary psychology a study of the thinking 
 process. Nearly all of the present day textbooks in 
 psychology either omit entirely a study of the thinking 
 process, or treat it very inadequately, on the ground that 
 logic is a separate science. Whether it is a separate 
 science or not, a knowledge of logical processes is an 
 essential element in the preparation of a teacher; and 
 since few normal schools offer a separate course in logic, 
 whatever knowledge of logical processes is acquired must 
 be obtained from the course in psychology. 
 
 In the present chapters an attempt is made to bring 
 the processes of the old formal logic into harmony with 
 the most advanced development of functional and physio- 
 logical psychology. That all mental functions are capable 
 of reduction to such processes as will render a uniform 
 treatment possible, is an article of faith with all psycholo- 
 gists ; but up to the present, it has not seemed possible to 
 give to the thinking processes a physiological and biologi- 
 cal interpretation. 
 
 Ypsilanti, January 2, 1910. 
 
CHAPTER I 
 
 THE LAWS OF ASSOCIATION. 
 So far "as association stands for a cause, it is between proceesses 
 
 in the brain. — James,, Psychology, Volume I., p. 554. 
 
 The socalled law of contiguity proves to be resolvable into the 
 law of similarity. — Spencer, Psychology, Volume 2, p. 505. 
 
 (In association) there is probably an increased closeness of 
 connection between cell and cell which makes for a greater likeli- 
 hood of recall for one when the other comes into consciousness. 
 —Pillsbury, Attention, p. 105. 
 
 Aristotle recalled the laws of this connection (association) to 
 four, or rather three ; contiguity in time and space, resemblance, 
 contrariety ; he even thought that they might all be carried up to 
 
 One, coexistence. — Hamilton, Metaphysics, p. 424. 
 
 These feelings (succession, similarity, coexistence) or their 
 contraries are the foundation of everything that we call a relation. 
 — Huxley's Hume, p. 81 . 
 
 It had been assumed that when two groups of cells — the sub- 
 stratum of two images — are excited at the same time, the nervous 
 wave circulates -from one group to the other through those com- 
 municating fibers that are so numerous in the brain. — Binet, Psy- 
 chology of Reasoning, p.', 1 85. 
 
 Contrast, however, is only a special case of similarity. Only, 
 and in fact, just those ideas contrast that differ in one point while 
 they are similar in very many other points.— Ziehen, Physiological 
 Psychology, p. 207. 
 
 The fundamental conception that all processes of thought can 
 be reduced psychologically to the association of ideas will at all 
 
 events endure. — Ziehen, Physiological Psychology, p. 244-5. 
 
 On the contrary we shall hold to the fact that all these activities 
 (understanding, reason, power of judgment, sagacity, fantasy, etc.) 
 simply represent varieties of the association of ideas. It would not 
 be at all difficult to reduce all these forms to the one fundamental 
 form of association by purely psychological reasoning.— Ziehen, 
 Physiological Psychology, p. 244-5. 
 
8 The Thinking Process 
 
 So far from association by similarity being resolvable into con- 
 tiguity, every association by contiguity on the contrary presupposes 
 an association by similarity, or at least, immediate recognition. — 
 Hoffding, Psychology, p. 1 57. 
 
 From this point of view the association between part and 
 whole would be the typical form of association. This fundamental 
 law of all association of ideas might be called the law of totality.— 
 Hoffding, p. 159. 
 
 Contrasts often belong to the same general conception ; just 
 as two poles are removed, each in its own direction, from a com- 
 mon center. Dwarf and giant both deviate from the ordinary 
 medium height. — Hoffding, p. 161 . 
 
 Whence we see clearly that the ultimate law of association of 
 feelings as above described has a definite physical counterpart, and 
 there is no room for any other law of association of feelings.— 
 Spencer, Psychology, Volume I, p, 258. 
 
 What Association Is. — One idea succeeds another in 
 the mind. It is impossible to retain one idea without 
 variation for a longer time than about three-fifths of a 
 second, and the whole series that follow one another is 
 called a train of ideas, or a train of thought. 
 
 If we write down the nine words that occur to the 
 mind after a first one has been suggested, we shall have 
 a train of ideas. Suppose the first word is watch. The 
 following nine words, or ideas, that follow may be gold t 
 mine, men, women, dress, pretty, witty, funny, pun. We 
 shall need to answer the question why each word instead 
 of some other follows the preceding. Gold follows watch 
 because there is a distinct relation between watch and 
 gold which we may call the relation of object and mate- 
 rial. Gold is the material out of which a watch is fre- 
 quently made. Mine follows gold because of the relation 
 existing between them. Mine is the source from which 
 the material comes, and the relation may be called material 
 and source. Men follows upon mine in consequence of a 
 similarity of sound. Women follows men, because of a 
 
Laws of Association 9 
 
 relation of contrast. Also, we may notice that there is a 
 similarity in sound in the final syllable of women. Dress 
 is associated with women, and the relation is one that we 
 may call contiguity. Pretty follows the word dress because 
 of the fact that pretty is a quality of dress, The relation 
 is one of substance and quality. Witty follows pretty, the 
 relation being a similarity in sound. Funny is related 
 to witty, there being a similarity in meaning. Pun 
 follows funny, the relation being both one of similarity 
 in meaning and in sound. 
 
 Laws of Association.— We see, then, that there is a 
 reason for the fact that each word follows the one that 
 preceded it, and that reason is the existence of a relation 
 between them. We have stated several relations, and 
 there are many more. These relations are called Laws of 
 Association. 
 
 Older psychologists worked industriously to discover 
 a complete list of the laws of association, and it was a 
 very common occurrence for a psychologist to discover 
 and formulate a new law. We see that to make a 
 complete list of the laws of association is necessarily 
 impossible, for there are just as many laws of association 
 as there are relations that may exist between objects. 
 
 Some of the Laws. — Some of the laws of association 
 that psychologists discovered were the following: 
 Contiguity, coexistence, contrast, cause and effect, 
 similarity, part and whole, substance and quality, material 
 and source. Many others might be mentioned, but these 
 will sufficiently illustrate the matter. When many laws 
 had been discovered, then psychologists undertook to 
 reduce them to a smaller number, or to show that all of 
 them were forms of a single law. Considerable success 
 attended their efforts, and some psychologists believe that 
 
10 The Thinking Process 
 
 the law of contiguity might be made to include all of them. 
 The law of contiguity is a statement of the relation 
 between two things that have existed, or do now 
 exist, in the same place. The law of coexistence is a 
 statement of the relation between two things that 
 have existed at the same time. 
 
 Others believe that the law of similarity would be 
 sufficiently inclusive to cover all the relations, and still 
 others that the law of part and whole, called the law of 
 totality, might be sufficient. It does seem possible to 
 reduce all laws of association to a single law, and it seems 
 advisable to call that law the law of resemblance. 
 
 Definition of Each. — The law of contiguity means that 
 there is a relation between two objects or events that have 
 existed in the same place, such that when we experience 
 the idea of the one it is likely to be succeeded by the idea 
 of the other. Rome, Tiber, Vatican are related by the 
 law of contiguity. So two students who have graduated 
 from the Normal college are thus related, although one 
 may have been a student in 1865 and the other in 1909. 
 
 The law of coexistence is a statement of the relation 
 between two objects or circumstances that have 
 occurred at the same time, such that when we experience 
 the idea of the one it is likely to be succeeded by the idea 
 of the other. The discovery of America and the invention 
 of printing are two events thus related, for they occurred 
 approximately at the same historical period. So two 
 students of the Normal college who have attended school 
 at the same time are related by the law of coexistence. 
 
 The law of contrast is the statement of relation 
 existing between two things that are different, such that 
 when the idea of the one is experienced it is likely to be 
 followed by the idea of the other. The idea of a tall man 
 
Laws of Association 11 
 
 is likely to be followed by the idea of a short man. The 
 idea of a cold day is likely to be followed by the idea of a 
 warm one. 
 
 The law of part and whole is a statement of the 
 relation existing between the part and the whole, such 
 that when the idea of the part is experienced it is likely to 
 be followed by the idea of the whole, or the idea of the 
 whole is likely to be followed by the idea of the part. 
 Thus the idea of a particular window of a house is likely 
 to be followed by the idea of the whole house, and the 
 idea of the blade of a knife is likely to be followed by the 
 idea of the knife itself. 
 
 Reduction to the Law of Resemblance. — The law of 
 
 contiguity may be reduced to the law of resemblance. 
 Contiguity means that relation of existing in the same 
 place, or contiguous portions of space. Two objects, 
 events or circumstances that are related to each other by 
 the law of contiguity resemble each other in the element 
 of position, and there is the element of sameness of place 
 in them. Two men who are students of the Normal 
 College are botn alumni, or Normal College men, and 
 they recognize a kinship with each other. Similarly the 
 law of coexistence is a statement of the relation of 
 resemblance, and two objects or events that coexist 
 resemble each other in time. The resemblance is often 
 much closer than this expression would suggest. Two 
 students in the Normal College in the year 1909 resemble 
 each other much more closely than does a student of 1909 
 resemble one of 1865. Two present year students 
 resemble each other in manners, dress, habits of fhought, 
 subjects studied, topics of conversation, and in many 
 other respects, much more closely than they resemble a 
 student of 1865. 
 
12 The Thinking Process 
 
 Reduction of the Law of Contrast.— It would seem 
 that if we could reduce the law of contrast to a law of 
 resemblance, we should be able to reduce every law to 
 that form. But it is not difficult to show that two ideas 
 of a contrasting pair are similar. The tall man is like the 
 short man in the fact that both of them are different from 
 the average man. But the resemblance goes deeper than 
 this. They are both men. They belong to the same 
 order of existence, and no contrast can exist between two 
 things that belong to different orders of existence. There 
 can be no contrast between the nominative case, and the 
 horse power of an automobile. The law of part and 
 whole is reducible to the law of resemblance. The part 
 is like the whole, and the whole is like the part. A cupful 
 of water is like the whole barrelful. The face of a watch 
 is like the watch just in so far as it constitutes a part of 
 the watch. 
 
 Reduction of the Law of Cause and Effect.— The law 
 of cause and effect will seem much more difficult to 
 reduce to the law of resemblance. Can we show that the 
 cause is like the effect and the effect is like the cause ? 
 The difficulty comes from an indefiniteness in the meaning 
 of cause. Philosophers are not at all agreed upon a 
 definition, and until we have a satisfactory meaning for 
 the word cause, we must expect to find difficulty in the 
 management of the idea. But if we consider cause as 
 being merely the force that is transmitted from the thing 
 in which it exists to some other thing, whose change of 
 position, movement or state is called the effect, we shall 
 see that cause and effect are both forces, one of which is 
 lost to the thing in which the cause exists and the other 
 appears in the thing that manifests the effect. Force is 
 the same, no matter in what form nor in what body it 
 appears. Also, we might show that the law of cause and 
 
Laws of Association 13 
 
 effect is one form of the law of contiguity, for the effect 
 must always be contiguous to a cause, or have some kind 
 of immediate contact with it. But the law of contiguity 
 is one form of the law of resemblance, hence the law of 
 cause and effect must also be. 
 
 Mediate Reduction. — Sometimes it is necessary to 
 reduce one of these laws to another and that other to the 
 law of resemblance before we can show that all laws are 
 capable of being thought of as forms of resemblance. It 
 will be seen that the resemblance may exist in only one 
 quality, and it is not necessary that all qualities shall be 
 the same. If two things were to be the same in every 
 respect, they would be identical, and instead of two, there 
 would be only one. There can exist no relation then, 
 without a difference. Resemblance depends upon and 
 includes difference. 
 
 Simultaneous Association.— The illustrations that we 
 have employed are those of successive association, and 
 the result is a train of ideas. But there is another kind of 
 association that may be called simultaneous association, in 
 which the associated processes occur in the same pulsation 
 of consciousness, or in about three-fifths of a second. 
 Such an association is illustrated by the process of 
 perception, in which the various sensations that constitute 
 the percept occur together, or nearly so. 
 
 Exemplifies the Same Law. — A question may arise 
 whether the qualities that exist in an apple and the 
 sensations that enter into our percept or our idea of the 
 apple are capable of being described in the same terms. 
 Are the qualities of an apple or the sensations in our idea 
 of the apple associated by the law of resemblance ? Do 
 
14 The Thinking Process 
 
 the qualities of an apple and the sensations that occur in 
 our percept or in our idea of an apple resemble each 
 other ? 
 
 Resemblance the Only Law in Perception.— The 
 
 sensations that enter into our idea of an apple appear 
 together, all of them being experienced in the same 
 pulsation of consciousness. It is not difficult to show that 
 they are associated by the law of resemblance. In the 
 first place, they are associated by the law of contiguity, 
 which is one form of resemblance, and they are associated 
 by the law of coexistence, which is another form of 
 resemblance. Also, no one of these qualities or sensations 
 is incompatible with the others, so there is the element of 
 compatibility; and besides this, sensations that are 
 experienced together modify each other, so that each one 
 affects every other. In this manner we may think of each 
 of them being cause and effect in relation to the others. 
 So it is not difficult for us to understand that the different 
 sensations that enter into our idea or percept are 
 associated by the law of resemblance as truly as are the 
 elements in a train of ideas. 
 
 Titchener's Formula. — Mr. Titchener describes a 
 formula for association which represents the facts very 
 nicely. He states it algebraically, thus : ab — be — cd—de — 
 ef—fg — gh — e tc. Let ab be one idea consisting of several or 
 many sensations, and be be another idea. A b is likely to 
 be followed by the idea be, because be is like ab, both 
 having the common element b, in which the resemblance 
 consists. So be is likely to be followed by cd, because of 
 the common element of resemblance c. 
 
 Angell's Figure— Mr. Angell uses a different figure for 
 association which is equally good. The figure consists of 
 
Laws of Association 15 
 
 two circles which intersect, and so have a common section 
 which represents the element of resemblance. Call one 
 circle A and another circle B and call the section that is 
 common to the two circles x. When the. idea which is 
 represented by A is experienced it is likely to be followed 
 by the idea B, because the idea B resembles the idea A in 
 the common element x. The resemblance will be greater 
 or less according as x is larger or smaller. 
 
 A and B represent two combinations of neurons. X represents the 
 neurons that are common to the two combinations. 
 
 Physiological Interpretation of Association.— Let us try 
 
 to think of these associations in physiological terms. We 
 have already learned that when we are experiencing an 
 idea, a nervous impulse is passing through some brain 
 center. Let the circle A represent the brain center or 
 combination of brain cells that is being traversed by an 
 impulse when we are experiencing the mental process a, 
 then the impulse passes out of the brain center A and into 
 the brain center B which corresponds to the idea b. Now 
 our question is why does the nervous impulse pass into B 
 rather than into C or D or some other brain center ? The 
 answer is evidently that there is less resistance between 
 A and B than there is between A and C or any other 
 brain center. The fact of little resistance is indicated by 
 the common section x. When the nervous impulse is 
 
16 The Thinking Process 
 
 traversing the center A, it is already traversing some of 
 the brain cells which enter into the constitution of B; so 
 in effect it is already in the center B when it is traversing 
 A. 
 
 Physiological Association Determined By Resistance.— 
 
 It will be seen that the nervous impulse passes from the 
 center in which it is at any time into that particular center 
 that offers least resistance to its entrance. One idea will 
 be followed by that idea which most closely resembles it, 
 and we may recognize that the nervous impulse is directed 
 by the resistance encountered. There is one modification 
 of this rule which we must notice; that is that by a process 
 of attention we may think of anything that we please, and 
 are not compelled to depend upon accidental association. 
 We may describe attention in physiological terms by 
 saying that it is the process by which we may modify the 
 resistance that a nervous impulse encounters, and so 
 direct the nervous impulse into and through a brain 
 center. This fact of attention must be taken into con- 
 sideration in any discussion of association. 
 
 Association Centers Not Necessarily Contiguous.— We 
 have been discussing the brain centers and their close 
 relation to each other as if the centers were contiguous, 
 and that this contiguity constituted the closeness of the 
 relation, but such is not necessarily the case. A combina- 
 tion of cells in the occipital lobe may be more closely 
 associated with a combination in the temporal lobe than 
 it is with another combination in the occipital lobe. 
 There are numerous bands of fibers, called association 
 fibers, that connect different portions of the brain with 
 each other. A nerve fiber offers little resistance to the 
 transmission of an impulse, and when two portions of 
 the brain are connected by means of fibers, they are 
 
Laws of Association 17 
 
 much more intimately associated with each other than 
 two other centers which are connected only through 
 neurons, or brain cells, with their insulating neuroglia. 
 
 Association Centers.— We have learned that the 
 centers of sensation and of motion are pretty definitely 
 localized in the brain. But when we have located as 
 many areas of this kind as possible, we find that there 
 are large portions of the brain in which no function is 
 described. Four of these large areas, which we have 
 recognized as unexplored areas, have been described 
 by certain writers, provisionally at least, as the 
 probable areas of the higher mental faculties. This 
 implies that there are higher mental faculties than 
 sensations and the association of ideas. Two of these 
 areas are in the frontal lobes and two are in the 
 parietal lobes. In them, various writers have located 
 the functions of attention, memory, thought, appercep- 
 tion. 
 
 Flechsifs Investigations.— Flechsig has definitely 
 located in these areas the function of association and 
 has called them association centers. Haeckel has taken 
 Flechsig's conclusions rather seriously, and has assumed 
 that these really include thought centers, and has called 
 this portion of the brain the thought portion, naming it 
 the phronema. This seems to imply that there is a 
 different portion of the brain involved in the experience 
 of the idea of an apple from that which is traversed by an 
 impulse when we perceive the apple. It implies that the 
 functions of memory, reasoning, ideation, attention, and 
 perhaps feeling, are located in particular places in the 
 brain, and that there are higher processes of thought 
 than those that are involved in the association. If we 
 understand the process of association as we have inter- 
 
18 The Thinking Process 
 
 preted it in physiological terms, we shall see that attention, 
 memory, ideation, and thought are processes that cannot 
 be localized in this way. It shall be our purpose to show 
 that there are no higher processes of thought than 
 those which are involved in these processes of associa- 
 tion. Hence it appears that the assumption of Flechsig is 
 entirely unnecessary, at least in the manner in which it is 
 understood by Haeckel and others; and Flechsig himself 
 has been compelled to modify his opinions very 
 materially. We may not be able at present to determine 
 what is the function of the unexplored areas, but there are 
 many sensation areas that we have not as yet located. 
 
 Effect of Attention Upon Association.— We have already 
 made the statement that attention can vary the resis- 
 tance and so modify association. When attention is 
 wanting, as in the case of sleep, then the nervous impulse 
 follows the path of least resistance, as it is determined 
 without attention, and we sometimes remember things 
 that we have forgotten in our waking hours. The fantas- 
 tic character of dreams may be explained in this way, and 
 sometimes oncoming disease has been recognized, which 
 was not noticed in the waking hours. 
 
 Imagination. — When ideas are associated, either by the 
 process of attention or without it, that have not been 
 associated in the original experience, we have the process 
 of imagination. There is no brain center for imagination 
 any more than there is for memory. Nervous impulses 
 pass from one brain center that has been traversed before 
 over into another that has been previously traversed, but 
 over a different pathway from that by which the brain 
 centers were entered in the original experience. If the 
 attention is active and directing the impulse, we have 
 
Laws of Association 19 
 
 the condition of active imagination; if the attention is 
 wanting, we have the condition of passive imagination, 
 or day dreaming. 
 
 DEnSMITlONS 
 
 Law of Association. — A law of association is a state- 
 ment of the relation existing between two ideas that 
 have been previously experienced, such that when one of 
 them is again experienced, it is likely to be followed 
 by the other. 
 
 Train of Ideas. — The succession of ideas that are 
 associated by successive association. 
 
 Successive Association.— That kind of association in 
 which ideas follow each other in successive pulsations 
 of consciousness. 
 
 Simultaneous Association. — That kind of association in 
 which the associated elements occur in the same pulsation 
 of consciousness. It is illustrated by the process of per- 
 ception, in which the associated sensations are experienced 
 at the same time. 
 
 Relation. — In the most general meaning of the term it 
 means any form of resemblance. It is the resemblance 
 that one object or one idea bears to another object or to 
 another idea. 
 
 Phronema. — As used by Haeckel, it means that portion 
 of the brain designated by Flechsig as association centers- 
 It consists of four large unexplored areas, two in the 
 frontal lobes and two in the parietal, in which no function 
 has been definitely located by psychologists. 
 
CHAPTER II 
 
 THE FORMATION OF THE GENERAL ABSTRACT NOTION. 
 
 General notions are the shorthand of thought. — Thomdike, 
 Psychology, p. 116. 
 
 We cannot, in fact, assert the existence of an difference with- 
 out at the same time implying the existence of an agreement. — 
 Jettons, Principles of Science, p. 44. 
 
 The end of philosophy is the detection of unity. — Hamilton, 
 Metaphysics, p. 366. 
 
 It may startle you to hear that the highest function of mind is 
 nothing higher than comparison, but I am confident of convincing 
 you of the paradox. — Hamilton, Metaphysics, p. 272. 
 
 Since the process of reasoning is essentially a detection of 
 similars, the great source of erroneous reasoning is the confusion 
 of things that are not really and fundamentally similar ; or in other 
 words, a want of discrimination. — Sully, Teacher's Handbook, P- 392. 
 
 Coupled with discrimination, it (agreement) exhausts the 
 meaning of what we call knowledge. — Bain, Mind and Body, p. 86. 
 
 The common features do not suffice to constitute an image. 
 Just as we cannot eat fruit in the abstract, but only apples, pears, 
 etc., so we cannot picture fruit in the abstract. But then, have we 
 psychologically, really general ideas ? — Holding, p. 1 66, 
 
 It has been shown that comparison is the fundamental form of 
 cognitive activity at all stages of development. But that which is 
 tc be an object of comparison must be confronted with something 
 else, either similar to it or different from it. — Hoffding, p. 216. 
 
 The Intellectual Process.— The intellectual process, as 
 distinguished from the affective or other process, is one 
 which results in knowledge. It makes us know some- 
 thing. A sensation makes us acquainted with the quality 
 of an object. Perception is the process which makes us 
 know an object, or the sum of all the qualities that we are 
 able to discover in it. The percept is the sum of all the 
 
General Abstract Notion 21 
 
 sensations that we receive from an object, both faint and 
 vivid, as they modify each other. We may obtain several 
 vivid sensations from an object, each of which is the 
 concomitant of a peripherally initiated impulse, and there 
 may be more than an equal number of faint sensations, 
 each the concomitant of a centrally initiated impulse. All 
 the sensations join themselves together, the concomitant 
 impulses become a single one, the sensations modify each 
 other, and the result is a percept. 
 
 The Singular Concrete Notion.— We obtain by percep- 
 tion, knowledge of a single individual thing, and this 
 percept we may call a singular concrete notion, whose 
 expression is a proper noun. A proper noun, then, is the 
 expression of a singular concrete notion. Very few 
 objects that we have occasion to indicate have proper 
 names, so we do not many times indicate them correctly. 
 We ordinarily employ a common name with limiting 
 words to indicate which particular thing we refer to. 
 Only persons, dogs, horses, and some other things are 
 ordinarily called by their proper names. 
 
 The General Abstract Notion. — A common noun is the 
 expression of a general abstract notion. The general 
 abstract notion, is the content or meaning of a common 
 noun. The word concept is frequently employed to 
 express what we shall understand by the term general 
 abstract notion, but for our purpose the latter term is 
 better. In order to understand how a general abstract 
 notion is obtained we shall necessarily employ con- 
 sciously a process which represents what actually occurs 
 as an unconscious process in nearly every case. Let us 
 suppose that we are intending to observe the process 
 by which we obtain a general abstract notion of insect. 
 We shall necessarily begin our study with an individual 
 
22 The Thinking Process 
 
 insect, such as a grasshopper. The first thing we do is to 
 look at the grasshopper as a whole, but this is not 
 sufficient to give us a satisfactory knowledge of the 
 grasshopper. Then we observe that the grasshopper is 
 composed of parts, of which we readily discover, the 
 head, thorax and abdomen. Now we fix our attention 
 upon the head, to the exclusion, for the time being, of 
 all other parts of the body. But we do not merely 
 look at the head as a whole; we observe that it is 
 made up of parts. We see the eyes, and fix our 
 attention upon them, excluding for that instant all other 
 parts of the head. We examine the antennae, fixing 
 our attention for the instant upon one of them, excluding 
 all other parts of the head. We count the segments of 
 the antennae, and in the process of counting we are seeing 
 just one segment of the antenna at a time, excluding all 
 other segments and all other parts of the head. We count 
 the segments, not for the purpose of finding out how 
 many there are, although this knowledge will necessarily 
 be obtained; but for the purpose of fixing our attention 
 for the instant upon each single segment, to the exclusion 
 of everything else. 
 
 Abstraction. — While we are thus fixing our attention 
 upon one thing to the exclusion of everything else, we are 
 engaged in the process, of abstraction. Abstraction is a 
 very important process, and really a very difficult one. 
 Our grammars usually define an abstract noun as the name 
 of some property or quality considered separate and apart 
 from the object to which it belongs, but this usually gives 
 a poor idea of the process. It is just as truly a process 
 of abstraction to consider the leg of a grasshopper, or the 
 second joint of the antennae, to the exclusion of all other 
 segments, as it is to abstract truth, redness, virtue, or any 
 other property from an object. 
 
General Abstract Notion 23 
 
 Analysis. — The second process employed in the study 
 of an object is analysis, which goes along parallel with 
 that of abstraction, and in fact can scarcely be separated 
 from it. Analysis differs from abstraction in the fact 
 that it examines the relations that one part holds to the 
 other parts. Our attention is focused, not upon the part 
 itself, but upon the relation that this part holds to the 
 other parts. We hear much of analysis in grammar and 
 arithmetic, but the process is the same wherever we find 
 it. In the analysis of the problems in arithmetic, we need 
 to perceive the relation that one quantity in the problem 
 holds to the other quantities. In the analysis of sentences 
 in grammar we need to see the relation that one element 
 in the sentence holds to the other elements. This process 
 of abstraction and analysis is a necessary step in the 
 formation of the general abstract notion, but it is all 
 included in the study of the individual. The analysis that 
 has been described may be called concrete analysis, for it 
 is an analysis of an individual concrete thing. 
 
 Related Knowledge.— After we have obtained as 
 thorough a knowledge as possible of an individual insect, 
 we proceed to study in the same way other related insects. 
 It will require not nearly so long a time to study a cricket 
 as it did a grasshopper, and we shall be able to see just as 
 many things and see them just as well in two hours on 
 the cricket as we did in twenty hours on the grass- 
 hopper. This is not, however, because we have cultivated 
 our observing powers, but because we have already a 
 large body of knowledge by means of which we can tie 
 up the new knowledge obtained in the study of the cricket. 
 It is by means of this related knowledge that we are able 
 to see so much more with the mind than we are with the 
 eye. 
 
24 The Thinking Process 
 
 Economy of Effort in Learning'.— The process by which 
 the acquisition of related knowledge is made is a process 
 of discrimination and comparison. In learning new 
 knowledge that is related to the old, we do not examine 
 every element of the new, but we examine and learn as 
 new only those elements in which, the new differs from 
 the old. The new elements may be a very small part of 
 the old, and since in learning the new we have to learn 
 only the elements that are different, we shall discover 
 that there is a great economy of effort. If we suppose 
 that there are ten elements in the old knowledge that we 
 have learned, and that in the new which we wish to learn 
 there are also ten, but only three of the ten elements are 
 different, and seven are the same, we can see that it will 
 require only three tenths as long to learn the new as it 
 did the old. Hence it is wasteful expenditure of energy 
 to learn anything as if it were unrelated to something 
 else. 
 
 Physiological Interpretation of Economy in Learning'. — 
 
 This fact of economy in learning, and the process by 
 which a new thing is learned by observing how it is like 
 and how it differs from that which is already known, may 
 be described in physiological terms. Let us suppose that 
 the brain center A (fig. 1,) is the center that is traversed 
 by one impulse when we experience the entire process of 
 learning the first thing. Let us suppose that brain center 
 B is the combination of cells that is traversed by impulses 
 when we experience the new thing that is to be learned. 
 Let us suppose that seven tenths of the cells in B are the 
 same cells that are found in A, but that three tenths of B 
 do not belong to A. The nervous impulse, having 
 already traversed all the cells in brain center A will 
 pass easily through that portion of B which is a part 
 of A. The difficulty and resistance will be encountered 
 
General Abstract Notion 
 
 25 
 
 principally in that part or brain center B which is not 
 found in A. Hence it is that the resemblance between 
 A and B permits the impulse to pass readily through 
 a large part of B. The effort of attention will 
 then be devoted to driving the impulse through 
 the portion of B which is not a part of A. The 
 economy of effort in learning, then, depends upon the 
 perception of the resemblance and the attention to the 
 difference that the new thing bears to the old which we 
 already know. 
 
 Order of Study. — Let us suppose that we have studied 
 a butterfly, beetle, bumblebee, squash bug, dragon fly, 
 housefly and grasshopper. The order in which they are 
 studied is not a matter of indifference. Certain relations 
 make themselves manifest if they are studied in one order 
 which do not appear, or which are much less easily seen 
 if they are studied in a different order. When we have 
 studied the individuals of these kinds then we are ready 
 for the next step. We need to notice the differences 
 which have manifested themselves to us while studying 
 the different insects, and we make a table such as is here 
 represented. This table represents the results of the 
 process of discrimination. 
 
 TABLE No. 1— DIFFERENCES OF INSECTS. 
 
 Wings 
 
 Mouth parts 
 
 Metamorphosis 
 
 Larva 
 
 Pupa 
 
 ORTHOP- 
 TERA 
 
 Grasshopper 
 
 Straight 
 Biting 
 
 Direct 
 
 Nymph 
 Active 
 
 LEPIDOP- 
 TERA 
 
 Butterfly 
 
 Scaly 
 Sucking 
 
 Indirect 
 
 Caterpillar 
 
 Inactive 
 
 HYMEN- 
 OPTERA 
 
 Bumblebee 
 
 Membrane 
 Biting and 
 lapping 
 Indirect 
 Grub 
 Inactive 
 
 COLEOP- 
 TERA 
 
 Beetle 
 
 Sheath 
 Biting 
 
 Indirect 
 
 Grub 
 
 Inactive 
 
 HEMIP- 
 TERA 
 
 Squashbug 
 
 Half 
 
 Sucking & 
 piercing 
 Direct 
 Nymph 
 Active 
 
 DIPTERA 
 Housefly 
 
 Two 
 Sucking 
 
 Indirect 
 Maggot 
 Inactive 
 
 NEUROP- 
 TERA 
 
 Dragonfly 
 
 Nerve 
 Biting 
 
 Direct 
 
 Nymph 
 Active 
 
26 The Thinking Process 
 
 Discrimination. — By discrimination, we mean the per- 
 ception of differences. It is an important process in 
 thinking, and every great discovery that has ever been 
 made has arisen from the recognition of finer and finer 
 points of distinction. A good example of this is found in 
 Lord Rayleigh's discovery of Argon. 
 
 Discovery of Argon. — Lord Rayleigh undertook to dis- 
 cover the exact weight of a given volume of nitrogen. He 
 first obtained nitrogen by extracting from the air all the 
 oxygen, water vapor, dust, carbon dioxide and everything 
 else that the air contained except the nitrogen, and he 
 ascertained the exact weight of a given volume of nitrogen 
 so prepared. Then he obtained some nitrogen by liberat- 
 ing it from its chemical compounds, and ascertained the 
 exact weight of a given volume of nitrogen so obtained. 
 The nitrogen obtained from the air weighed a very little 
 more than that which was obtained from the chemical 
 compounds. Repeating the processes merely showed 
 that there was a constant difference, existing always in 
 the same direction. 
 
 The difference was not very great. Other chemists 
 had weighed nitrogen, and had observed that nitrogen 
 obtained from the air did not weigh exactly the same as 
 did that which was obtained from chemical compounds ; 
 but other chemists had regarded the differences as non- 
 significant. They had accounted for it by supposing that 
 they had made an error in the weighing ; or that their 
 apparatus was slightly inaccurate; or that the amount 
 was less than the limits of possible error. But Lord 
 Rayleigh undertook to account for this minute difference, 
 and as a result of the finer discrimination that he employed 
 he discovered the presence of another element, which he 
 called argon, and which constitutes about one per cent of 
 the air. 
 
General Abstract Notion 27 
 
 Effect of Discovery. — But his discoveries did not stop 
 here. It led to the discovery of neon, krypton, xenon, 
 other substances of the same group in the air, and the 
 discovery of these substances made necessary a new 
 column in the table of chemical elements. It seems now 
 very possible that ether itself may ultimately be placed at 
 the head of this column, the zero group of elements, and 
 that we shall thus be furnished with a new and different 
 explanation of some of the most important phenomena of 
 the universe, if not a new hypothesis of the constitution 
 of the universe itself. Such are the far reaching effects 
 of making finer and finer discriminations. 
 
 Table of Resemblances. — Another process must now be 
 examined. While we have been studying these different 
 animals and observing how they differ from each other, 
 we have also been observing how they resemble each 
 other. We see that they all have three body divisions, 
 segmented abdomen, seventeen body segments, six legs, 
 two pairs of wings, jointed appendages, breathe by spira- 
 cles, all lay eggs, three thoracic segments, jaws move 
 sideways, one pair of antennae, compound eyes, chitinous 
 exoskeleton, double nerve cord and ganglia. We might 
 also observe that they are composed of many cells, are 
 bilaterally symmetrical, take solid food, exchange carbon 
 dioxide for oxygen, sexes different, and many other things. 
 However, table 2 will exhibit a sufficient number of resem- 
 
 TABLE No. 2— RESEMBLANCES OF 
 INSECTS 
 
 Housefly 
 
 Beetle 
 
 Squashbug 
 
 Butterfly 
 
 Grasshopper 
 
 Bumblebee 
 
 Dragonfly 
 
 Chitinous exoskeleton 
 
 Three bodyCdivisions 
 
 Seventeen body segments 
 
 Segmented abdomen 
 
 Jointed appendages 
 < One pair of antennae 
 
 Two pairs of maxillae 
 
 Three pairs of legs 
 
 Jaws move sideways 
 
 Compound eyes 
 
 Breathe by spiracles 
 .Double nerve cord and ganglia 
 
28 The Thinking Process 
 
 blances which we have observed to illustrate the process. 
 All the animals that we have studied manifest these 
 characteristics. They are alike in so many respects that 
 we may group their likenesses together and designate 
 their sum by a single word, insect. The use of the word 
 insect is a labor saving device. No very elaborate thinking- 
 could be carried on if we were compelled to state every 
 time one by one the entire list of characters in the table 
 that the word insect connotes. The word insect, then, 
 expresses the entire sum of characters which is repre- 
 sented by the table, or the general abstract notion. It is 
 abstract because it expresses the characters which have 
 been abstracted from the different individuals which we 
 have studied. It is general, because these characters are 
 all of them found in every individual which we have 
 studied. 
 
 Content of the General Abstract Notion.— -The general 
 abstract notion is always derived from a table of resem- 
 blances. In the case described, the table has been written 
 out and the notion has been obtained in a formal and 
 conscious way, but in nearly all cases in which we form a 
 general abstract notion, the discrimination and comparison, 
 and making of the table has been done in an unconscious 
 and informal manner. It is generally not at all the con- 
 scious process that we have described. We ordinarily 
 obtain our notion by reading a word in many different 
 connections, and the similarity of meaning in the different 
 places in which we have used it or seen it used, constitutes 
 for us the unconscious table of resemblances. We are 
 generally quite unable to state distinctly the different 
 characters that constitute the table and which make up 
 for us the general abstract notion. But the process of 
 comparison, is just as real, and the table of resemblances 
 is just as truly made as if it had been written out in a 
 formal way. 
 
General Abstract Notion 29 
 
 Different Contents.— From this conception of the 
 general abstract notion and the process of its formation, 
 some very evident and important corollaries are derived. 
 In the first place, no two persons are likely to have exactly 
 the same general abstract notion which a given word 
 expresses. Some persons may have a long table of 
 resemblances, and others have a short table; but both 
 tables will be expressed by the same word, and it will 
 inevitably mean somewhat different things to different 
 persons. Since it is generally true that children get hold 
 of words before they do the meanings, teachers find it a 
 large part of their difficulty to fill up the empty words of 
 children with a content. Inadequate tables of resem- 
 blances, which common nouns express, are the source of 
 many of the ludicrous mistakes that children make when 
 writing examination papers. They are ludicrous and 
 funny only to persons who have a fuller content of the 
 words. 
 
 No General Abstract Object. — Another corollary is that 
 the general abstract notion has no actual tangible repre- 
 sentative. It is merely a collection of characters, and the 
 word which expresses that table of characters will apply 
 to any individual that manifests those characters. But 
 any individual which manifests those characters will also 
 manifest other characters which make it an individual 
 and which will discriminate it from other individuals. 
 
 Abstract Notion Not An Image.— The fact that certain 
 persons habitually think in visual images has led many 
 psychologists to consider the general abstract notion, or 
 concept, as an image. The word concept is in a large 
 measure responsible for this error, and is often regarded 
 as an image. But auditory minded persons do not have a 
 visual image, and those persons who have most occasion 
 
30 The Thinking Process 
 
 to deal in a scientific manner with general abstract no- 
 tions, are most completely lacking in them. The botanist 
 or zoologist who classifies his individual objects, does it 
 often, without ever having seen or heard of a specimen of 
 the class to which he assigns his individual. His notion 
 of the family or genus is altogether a printed or written 
 description, which states merely the sum of characters, 
 and from this he classifies his individual. Just as the 
 person who has a complex number form is unable to 
 understand how one who has no number form can 
 possibly handle numbers, so the visual minded person is 
 unable to understand how a concept or general abstract 
 notion can be anything but a visual image. The 
 sum of the common characters is the general abstract 
 notion, while the sum of the common characters plus 
 the individual characters is the singular concrete notion. 
 Hence there are no general abstract objects, but only 
 singular concrete objects. 
 
 Not Derived From a Single Thing.— Another corollary 
 follows. We can never obtain a general abstract notion 
 from a single thing. When there was only one war 
 vessel called the Monitor, our notion of monitor was a 
 single concrete notion. But when other vessels of the 
 same type were constructed, then our notion of monitor 
 became a general abstract. 
 
 Comparison. — The process of perceiving resemblances 
 is called comparison. It is of equal importance with the 
 process of discrimination. The two processes may exist 
 in different degrees in the same person, although both 
 are of importance. The person who perceives resem- 
 blances is the person who is able to become a philosopher, 
 and to discover the element of identity in diverse 
 phenomena. 
 
General Abstract Notion 31 
 
 The Only Process of Learning.— The two processes of 
 discrimination and comparison lie at the foundation of all 
 processes of learning. There is no way of learning any- 
 thing except by discovering how it is like or how it differs 
 from something else. This is merely another way of 
 saying that all knowledge is relative, and that nothing 
 exists out of relation. Knowledge begins when we ob- 
 serve differences and resemblances. 
 
 Resimilation. — As we were able to reduce all laws of 
 association, even the law of contrast, to the law of 
 resemblance, and so define all relation as resemblance, so 
 it is possible to show that the processes of discrimination 
 and comparison are merely different aspects of the same 
 process. It is impossible to perceive difference without 
 at the same time discovering resemblance. We may call 
 this one process the perception of resemblance, but in 
 order to avoid the use of the word perception in the 
 expression perception of resemblance, as well as to avoid 
 adopting one of the two processes which we have de- 
 scribed to the exclusion of the other, we may better coin 
 a new word. Let us use the word resimilation, to mean 
 perception of resemblance. 
 
 Physiological Interpretation of Resimilation.— It is diffi- 
 cult to understand how discrimination and comparison 
 may be reduced to the same process, unless we image it 
 in physiological terms. Let the circle which represents 
 the brain center A have seven tenths of its cells common 
 with brain center B. The element of resemblance will 
 be represented by the common section x, and the element 
 of difference by the other portions of the two circles. 
 When a nervous impulse passes through the circle A and 
 from there into the circle B, the transmission of the im- 
 pulse through the common section will be the concomitant 
 
32 The Thinking Process 
 
 of the perception of resemblance, and there will be 
 feeling of similarity. But in the transmission of the 
 impulse through the two brain centers, the impulse w\\l 
 pass through the portions of the two centers that are not 
 common and the concomitant feeling will be a feeling of 
 difference. Hence the physiological concomitant of the 
 process of discrimination is the transmission of the impulse 
 through the non-common cells, and the physiological 
 concomitant of the process of comparison will be the 
 transmission through the common cells. Since in the 
 process of transmission through both centers both the 
 common and the non-common cells are traversed, we 
 shall see that both processes have their concomitants in 
 the single process of the transmission of the impulse 
 through the entire group of cells. The transmission is 
 a single physiological process, and the process of re- 
 similation is its single psychological concomitant. 
 
 DEFINITIONS 
 
 General Abstract Notion. — A general abstract notion is 
 the sum of all the characters that are common to a series 
 of objects. 
 
 Common Noun. — The expression of a general abstract 
 notion. 
 
 Singular Concrete Notion.— A percept; or the sum of 
 all the sensations that we obtain from an object. Each 
 sensation in us corresponds to a quality in the object. 
 
 Proper Noun. — The expression of a singular concrete 
 notion. 
 
 Abstraction. — The process of examining or attending 
 to a single part or property of an object to the exclusion 
 of the other parts. 
 
General Abstract Notion 33 
 
 Analysis.— The process of examining a part or quality 
 of an object in its relations to other parts or qualities. 
 
 Discrimination— The process of perceiving differences. 
 
 Comparison. — The process of perceiving resemblances. 
 
 Generalization. — The entire process involved in forming 
 a general abstract notion. It includes abstraction, analysis, 
 discrimination, comparison. The process results not 
 merely in the formation of a general abstract notion, but 
 also in the discovery of a law, or the statement of a 
 principle. 
 
 Resimilation. — The perception of resemblance. The 
 word resemblance is here used to include also difference, 
 as indicated before. The entire process of discovering 
 likeness and difference. 
 
CHAPTER HI 
 
 PROPERTIES OF THE GENERAL ABSTRACT NOTION 
 
 Origin of the Notion.— The general abstract notion is 
 the sum of all the resemblances which we have discovered 
 in the objects studied. The common noun which expresses 
 it has its meaning for us in that table of resemblances. 
 When we have said insect, we have said everything that 
 is included in table 2. In only a very few cases is such a 
 table consciously prepared, but every common noun is 
 obtained from a table that is just as real as if it were 
 consciously written out. Every general abstract notion is 
 derived from such a table. 
 
 Logical Definition. — This, however, does not enable us 
 to make a definition. We may say that a beetle is an 
 insect — , but if we stop here we have not made a defini- 
 tion. We have said a great deal; we have said everything 
 that is included in the table of resemblances, but we have 
 not defined beetle. A grasshopper is an insect, and so is 
 a bumblebee, from which we have not discriminated 
 beetle. We may make such a discrimination by inserting 
 in our definition the characters in the table of differences 
 in the column under beetle. Then we shall have a defini- 
 tion of the following form : A beetle is an insect that has 
 sheath wings, biting mouthparts, and indirect metamor- 
 phosis. 
 
 Parts of the Definition.— It will be seen that this 
 definition contains two parts; first the name of the 
 comprehensive group, which is derived from the table 
 of resemblances, and second, the differences that dis- 
 tinguish the thing we are defining from other members 
 
General Abstract Notion 
 
 35 
 
 of the same group. The first is a general abstract 
 notion derived from a table of resemblances, and is called 
 the genus. The second element of the difinition consists 
 of the characters found in the table of differences, and are 
 called the differentia. No definition can be satisfactory 
 that does not include both of these elements. Such a 
 definition is called a logical definition, and it expresses 
 the nature of the thing defined. Most of our dictionary 
 definitions are not logical definitions, but statements of 
 descriptive characteristics by means of which we may be 
 able to identify the thing described. When I say that 
 Mr. Laird's house is 318 Forest Avenue, I have not made 
 a definition of Mr. Laird's house, but merely stated one 
 characteristic by means of which it may be identified. 
 
 Notion of Arthropod. — We have now arrived at a 
 general abstract notion of insect and by a similar process 
 we may reach a general abstract notion of arthropod. If 
 we study a spider, centipede and crawfish we shall see 
 that they have characters in common with the grass- 
 hopper, but that the number is not so large as that which 
 exists between the insects previously studied. Let us 
 examine tables 3 and 4. 
 
 TABLE No. 3.— DIFFERENCES OF ARTHROPODS. 
 
 INSECTA 
 Grasshopper 
 
 ARACHNIDA 
 Spider 
 
 MYRIAPODA 
 Centipede 
 
 CRUSTACEA 
 
 Crawfish 
 
 Body divisions- 
 Skeleton 
 
 Antennae 
 
 Eyes 
 
 Breathing 
 
 Number of legs. 
 
 Three 
 
 Chitinous 
 One pair 
 Compound 
 Spiracles 
 Three pairs 
 
 Two 
 
 Chitinous 
 None 
 Simple 
 Air gills 
 Four pairs 
 
 One (differen- 
 tiated) 
 Chitinous 
 One pair 
 None 
 Spiracles 
 31 pairs 
 
 Two 
 
 Calcareous 
 Two pairs 
 Compound 
 Gills 
 Ten 
 
The Thinking Process 
 
 TABLE No. 4— RESEMBLANCES OF 
 ARTHROPODS 
 
 Grasshopper 
 Spider 
 Centipede 
 Crawfish 
 
 ' Exoskeleton 
 Jointed appendages 
 White blood 
 Jaws move sideways 
 Double nerve cord and ganglia 
 Specialized breathing organs 
 
 From table 4 we are able to arrive at a general 
 abstract notion of arthropod, and from table 3 we are able 
 to make a logical definition of insect. We may define an 
 insect as an Arthropod which has a chitinous exoskeleton, 
 two pairs of wings, one pair of antennae, seventeen body 
 segments, compound eyes, three body divisions, breathes 
 by spiracles. 
 
 Different Ranks.— It will be seen from this that the 
 notion arthropod is not of the same rank as is the notion 
 insect. Arthropod includes all the individuals that are 
 included in the notion insect, but there are many 
 arthropods that are not insects. Some arthropods are 
 spiders and others are centipedes. General abstract 
 notions are of different ranks. 
 
 Scientific Notions. — Zoologists and botanists, whose 
 subjects better illustrate the process of making a general 
 abstract notion than any others, and who have been 
 compelled to study the process by which it is made, have 
 devised a convenient method of expressing this fact. 
 The general plan is as follows : Individuals that are 
 alike, as nearly alike as parent and offspring, make up a 
 species. Species that are alike make up a genus. Genera 
 that are alike constitute a family. Families that are alike 
 make an order. Orders that are alike constitute a class. 
 Classes that are alike make up a branch, and branches 
 that are alike make up a kingdom. Individual, species, 
 genus, family, order, class, branch, kingdom are the names 
 of different ranks of general abstract notions that 
 
General Abstract Notion 37 
 
 botanists and zoologists have adopted. There are many 
 subdivisions and other ranks, but these eight rankings 
 are universally recognized. In some books on zoology 
 there are employed as many as twenty one different 
 rankings of general abstract notions. 
 
 Rank Depends Upon Degree of Resemblance.— We 
 
 have said that notions that are alike, which contain the 
 same characters, constitute the notion of the next higher 
 rank. It will be seen at once that the essential process 
 in making each notion is the perception of resemblance, 
 and that the degree of resemblance, as represented by 
 the number of characters, varies with the notions of 
 different ranks. 
 
 Genus. — We have used the term genus, in our 
 description of the process of making a logical definition. 
 It will be seen that the word means something different 
 from what it does when we speak of genus as one of the 
 distinctions of rank of general abstract notions. As we 
 use the term in making a logical definition, it means any 
 comprehensive group that is composed of groups or 
 notions of a lower rank. When we speak of genus as one 
 of the ranks of general abstract notions, we mean a rank 
 of a particular degree of complexity. In making a logical 
 definition, we must use as our genus the name of a 
 comprehensive group that shall include the one we are 
 defining. Since there may be several groups of different 
 ranks that will include the one we are defining, it is 
 necessary to know which group we ought to employ. 
 Thus in making our definition of insect we may use for 
 our genus either arthropod or animal, since both of them 
 are general abstract notions that include insect; but we 
 should always use the notion of the next higher degree of 
 complexity, or as logicians express it, the proximum genus. 
 
38 The Thinking Process 
 
 Coordinate Ranks.— Of course it will be understood 
 that kingdom, class, order and so on are names of ranks, 
 not names of notions. There may be several notions, co- 
 ordinate with each other and all having the same rank. 
 Thus in the rank of kingdom, there are three general 
 abstract notions, the animal, mineral and vegetable king- 
 doms. So zoologists describe eight different branches of 
 the animal kingdom, all coordinate with each other, but 
 each notion designated by a different name and composed 
 of a different group of characteristics. 
 
 Comparison of Tables.— If we examine tables three 
 and four, we shall see that table four is a shorter table 
 than is table two. Also we shall see that all the characters 
 found in table four exist in table 2, and that the characters 
 in table 2 which are not found in table 4 are found in 
 table 3. Table 2 has been split up into a table of 
 differences and a table of resemblances. 
 
 Comprehension. — As our notion of higher rank is 
 formed, the table of resemblances becomes shorter and 
 shorter, and the number of resemblances among the 
 individuals that have been examined become fewer. This 
 fact is expressed by saying that the comprehension of the 
 notion is less. Comprehension is that property of the 
 notion which refers to the number of characters that 
 make it up. The greater the number of characters, the 
 greater the comprehension. The table of resemblances 
 which constitutes the notion of insect is longer than that 
 which constitutes the notion arthropod, and the notion 
 insect is said to have greater comprehension than the 
 notion arthropod. 
 
 Extension.— But at the same time that the table of 
 characters has been growing shorter, the number of 
 individuals that manifest those characters has become 
 
General Abstract Notion 39 
 
 greater. There are more arthropods than there are 
 insects. This property of the notion is expressed by 
 saying that the extension of the notion has been 
 increased. Extension is that property of the notion that 
 refers to the number of individuals which manifest the 
 characters constituting the notion. In general we may 
 say that extension and comprehension are reciprocally 
 related to each other. The greater the extension the less 
 the comprehension, and the less the extension the greater 
 the comprehension. 
 
 Summum Genus. — We cannot define beetle until we 
 have a notion of insect. We cannot define arthropod 
 until we have a notion of animal, and we cannot define 
 animal until we have a notion that is extensive enough to 
 include animal and plant. We must always have a notion 
 of sufficiently high rank to include as a species the notion 
 that we are defining. So in order to define animal we 
 must have a notion, such as organic being, that would 
 include animals and plants. In order to define organic 
 being we must have a notion that will include organic 
 being and inorganic being. This notion may be called 
 simply being. But we cannot define being until we shall 
 have a notion sufficiently extensive to include both being 
 and not-being, and what we may call this notion no one 
 can say. The summum genus, in the words of the old 
 logicians, cannot be defined. But it is upon this concep- 
 tion, that being and not being are identical, that Hegel, 
 the great philosopher, founded his whole system. 
 
 Other Abstract Notions.— We have been using illus- 
 trations that lead to the formation of the general abstract 
 notion expressed by a common noun; but it must be 
 evident that it is the same process that leads us to the 
 meaning of any notion, no matter what part of speech 
 
40 The Thinking Process 
 
 expresses it. The notion expressed by a verb is as truly 
 a general abstract notion as is that expressed by a 
 common noun, and so is the notion expressed by an 
 adjective or a preposition. Nearly all of our common 
 words are of this kind. The only real things are the 
 particular individuals that we perceive. We may define 
 some of our most difficult words as expressions of general 
 abstract notions. Thus life may be defined as the general 
 abstract notion which is composed of the characters that 
 are common to all living things. Mind is the general 
 abstract notion composed of all the characters that are 
 common to all mental processes. Character is the general 
 abstract notion consisting of all the qualities common to 
 the actions of a person. These are helpful and necessary 
 processes of thinking, but we lead ourselves into error if 
 we consider them as real existing entities and make of 
 them causes. 
 
 Generalization. — So far we have been discussing the 
 formation of the general abstract notion, and have 
 described the process in detail. The entire process may 
 be called generalization, and leads not merely to the 
 formation of a general abstract notion, but when applied 
 to other processes, it may result in the formation of a law 
 or the statement of a principle. The essential element in 
 the process is resimilation, which is illustrated in our 
 physiological figure by supposing that the same cells are 
 traversed in the course of the transmission of a nervous 
 impulse through two different brain centers. 
 
 DEFINITIONS 
 
 Logical Definition. — A logical definition is a statement 
 that manifests the nature of the thing defined. It always 
 includes two elements, the genus and the differentia. 
 
General Abstract Notion 41 
 
 Genus. — Genus is the name of the comprehensive 
 group to which the thing we are defining belongs. It is 
 always a general abstract notion. 
 
 Differentia. — Differentia are the differences or 
 characters which separate the thing we are defining from 
 other members of the same group. 
 
 Extension. — Extension is that property of the general 
 abstract notion that refers to the number of individuals 
 included under the notion, or to the number of individuals 
 that manifest the characters that constitute the notion. 
 
 Comprehension. — Comprehension is that property of 
 the general abstract notion that refers to the number of 
 characters that constitute the notion. 
 
CHAPTER IV 
 
 JUDGMENT 
 
 The association of ideas in the case of judgment is almost 
 without exception an intimate association of simultaneous ideas, 
 and an association in which conceptions of relation are of special 
 importance. Of all possible associations, a judgment is just that 
 select association in which no contradictory ideas occur. — Ziehen, 
 'Physiological 'Psychology, p. 228. 
 
 Every proposition expresses resemblance or difference of the 
 things denoted by its terms.— Jeoons, 'Principles of Science, p. 24. 
 
 . A similar interpretation of the relation leads Binet to assert 
 that all perception is judgmont. Both of these terms serve merely 
 to point out the similarities of the perception process to the more 
 complicated mental processes, and in so far we may accept them.— 
 Pillsbuiy, Attention, p. 118. 
 
 Judgment is the mental assertion of the degree of relationship 
 arrived at in some one stage of the process of conception. — Baldwin, 
 Handbook, Vol. I, p. 283. 
 
 Meaning' of Judgment.— The word judgment is used 
 with a greater variety of incompatible meanings than is 
 any other word in psychology. It is employed to mean 
 discrimination, belief, perception, analysis, distribution of 
 sensational elements, the fundamental element in eyery 
 intellectual process, and perhaps several other meanings. 
 At the same time, different users of the word seem to 
 believe that they are talking about the same thing, each 
 claiming that his use of the word is the true meaning. 
 Hence it is impossible to use the word at all without a 
 careful definition of what is meant by it. 
 
 By judgment, in this book, we shall mean the move- 
 ment of thought involved in perceiving the resemblance 
 between two notions. This is the common meaning 
 employed by writers on logic, and it is both logical and 
 
Judgment 43 
 
 psychological. That there is a possibility of comparing 
 two notions will be denied by no one, and that a psycho- 
 logical process is employed in making the comparison is 
 equally evident. It is that psychological process which is 
 employed here as the content of the word judgment. 
 
 Process of Judging*. — In judging we hold in mind two 
 notions and decide that they agree or disagree. Thus we 
 may hold in mind the notion of snow and the notion of 
 whiteness and we decide that they agree. We hold in 
 mind the notion of insect and the notion of vertebrate, 
 and we decide that an insect is not a vertebrate. In every 
 case we decide upon the agreement or disagreement; we 
 discover a resemblance or a difference. We express the 
 judgment by is or is not. Such a judgment is called a 
 qualitative judgment, and there are two varieties. The 
 judgment of agreement is called the affirmative, and the 
 judgment of disagreement is called the negative judgment. 
 
 Two Kinds of Judgment.— In our study of the laws of 
 association we learned that it was possible to reduce the 
 law of contrast to the law of resemblance and that we 
 might use the term resemblance in a sense broad enough 
 to include the element of difference. Similarly it is 
 possible to discover that every judgment consists in the 
 perception of resemblance between two notions. How- 
 ever, it will be convenient for us to retain the distinction 
 between negative and affirmative judgments. 
 
 Judgment A Resimilation— We have learned that in a 
 percept we perceive the resemblance between the qualities 
 of an object, and that the percept is really the sum of 
 sensations associated by the law of coexistence and con- 
 tiguity. In forming a general abstract notion, we perceive 
 the resemblance between two or more singular concrete 
 notions. In making a judgment we perceive the resem- 
 
44 The Thinking Process 
 
 blance between two general abstract notions, although it 
 is not necessary that the notions shall both of them be 
 abstract. The similarity between perception, forming a 
 general abstract notion, and judgment, is that in all of 
 them there is the same process of the perception of 
 resemblance. The difference exists in the things between 
 which the resemblance is perceived. 
 
 Physiological Interpretation of Judgment.— The same 
 figure may be employed to express the physiological 
 process of the perception of resemblance that we have 
 already described in the process of forming the general 
 abstract notion. Two circles having a common section x 
 may represent the two combinations of cells that are 
 traversed by impulses when we experience the two 
 general abstract notions whose resemblance is perceived. 
 The nervous impulse passes directly from one brain center 
 to the other by means of the common section when we 
 make a judgment of agreement. Even if the judgment 
 be one of disagreement, we shall find that the same 
 figure will illustrate it. 
 
 Propositions. — The expression of a judgment is a 
 proposition. Every proposition contains three elements 
 which correspond to the three elements in a judgment. 
 The three elements of the proposition are the subject, 
 predicate and the copula. In every judgment we shall 
 find that there are two notions and the judgment itself. 
 The two notions, however, are not of the same rank in 
 the judgment, and perform different functions. One of 
 the notions is a standard of comparison, and the other 
 notion is brought up beside it to be compared with the 
 standard. The expression of the notion that is the 
 standard of comparison is the predicate of the proposition 
 and the expression of the notion that is compared to the 
 standard is the subject. The copula is the expression of 
 the judgment itself. 
 
Judgment 45 
 
 Varieties of Judgment. — In general it is true that the 
 extension of the notion which is expressed by the predi- 
 cate is greater than the extension of the subject notion. 
 But the comprehension of the subject is greater than the 
 comprehension of the predicate. Since we have defined 
 the notion as the sum of characters, it appears that it is 
 necessary for us to indicate the difference between the 
 two notions by making the circle which will represent the 
 cells traversed by an impulse when we experience the 
 subject notion larger than that which expresses the predi- 
 cate notion. Also, it will seem that in many cases of a 
 judgment of agreement it will be necessary to include the 
 predicate notion wholly within the circle represented by 
 the subject notion. If the agreement is complete, as may 
 be expressed by such propositions as six is six; or once 
 one is one; or pigs is pigs, then we may express the fact 
 by making the two circles coincide. Such judgments are 
 called identities. Nearly all judgments, however, are 
 perceptions of agreement in merely certain respects, or 
 partial identities. A judgment of disagreement is one in 
 which the particular element in the notion that is com- 
 pared is not found in the other. It must be represented 
 by two circles, each indicating a combination of brain cells, 
 some of which are common to the two centers, but the 
 particular cells that correspond to the element in the one 
 that is compared with the other does not belong to the 
 common section. If the two combinations were entirely 
 different, the process would not be an act of judgment 
 but one of reasoning. 
 
 Another Interpretation of Judgment.— There is another 
 opinion concerning the nature of judgment which is so 
 well known that it must be described in this place. That 
 opinion is that judgment is not a process of comparing 
 separate notions, but is setting apart and separating from 
 
46 The Thinking Process 
 
 each other the elements that enter into a single notion. 
 The notion as it is first obtained consists of an un- 
 differentiated whole. The process of judging consists in 
 separating this undifferentiated whole into its elements 
 and recognizing them as separate parts. 
 
 A Criticism. — This idea is a very old one. It was that 
 adopted by Crousaz as far back as 1724, and although it 
 has the approval of some of our best psychologists, it 
 cannot be made to conform to the process by which a 
 notion is built up in the mind of a child. The percept of 
 an apple that a child gets is obtained part at a time. In 
 case of a little child the senses do not all become 
 functional at once, and when two or more sensations are 
 experienced at the same time, no perception occurs until 
 these sensations are associated by the law of resemblance. 
 So when we see an object of complex combination, not all 
 the sensations will be experienced the first time that 
 correspond to the different qualities. A peripherally 
 initiated impulse that is established by one part of the 
 object will not be transmitted through its appropriate 
 brain center, unless the impulse becomes very strong, or 
 unless the same center has been traversed before. Hence 
 it is that although we may look at a complex object, such 
 as a landscape, we fail to experience all the sensations 
 that we shall ultimately obtain. The process of obtaining 
 a more adequate perception of the complex object is not a 
 process of analysis and separation, but a process of accre- 
 tion and association. 
 
 Judgment As The Fundamental Process.— The term 
 judgment is also employed to designate the fundamental 
 process that is common to all intellectual operations, and 
 the attempt is made to identify it with the process pre- 
 viously described. It is the purpose of this book to show 
 
Judgment 47 
 
 that all intellectual processes have a common element, and 
 that different intellectual processes differ principally from 
 each other in degree of complexity. The writer 
 believes that the fundamental process can best be 
 described by calling it resimilation, or the perception of 
 resemblance, and that to call it judgment is a very un- 
 fortunate designation. 
 
 Four Kinds of Propositions. — The distinction between 
 positive and negative judgments is called a qualitative 
 difference. But we may have judgments that apply to 
 all the particulars, or universal judgments, and those that 
 apply to only some, or particular judgments. This is a 
 distinction in quantity. Each kind of judgment, and 
 consequently each proposition, may be distinguished 
 according to both its quality and quantity. Hence we can 
 discover that there are four kinds of propositions; univer- 
 sal affirmative, universal negative, particular affirmative, 
 particular negative. These kinds of propositions may be 
 illustrated as follows : 
 
 Universal affirmative — All grasshoppers have six legs. 
 
 Universal negative — No grasshopper has six legs. 
 
 Particular affirmative — Some grasshoppers have six 
 legs. 
 
 Particular negative — Some grasshoppers do not have 
 six legs. 
 
 Although in the proposition, all" insects have six legs, 
 legs is not the grammatical predicate, but the object of 
 have, it is the psychological predicate, and the word have 
 expresses the agreement of the two notions even better 
 than the copula is. To say that an insect has six legs 
 implies that the character of six leggedness is one of the 
 group of characters in the table of resemblances which 
 constitutes the general abstract notion of insect. 
 
48 
 
 The Thinking Process 
 
 Symbolic Propositions.— The four kinds of propositions 
 are expressed in a shorthand manner by the letters A E I 
 O. A expresses the universal affirmative, E is the uni- 
 versal negative, I is the particular affirmative, and is 
 the particular negative. 
 
 Diagram of Relations.— There is an old diagram which 
 is employed to express the relations that these proposi- 
 tions bear to each other. The diagram is a square with 
 two diagonals. At the upper left hand corner of the 
 square, is placed the letter A. At the upper right hand 
 corner, E; at the lower left hand corner I, and at the lower 
 right hand corner the letter 0. 
 
 If we examine the four propositions that we have 
 employed to illustrate the different kinds of judgments, 
 we shall see that certain relation exist which are necessary 
 and inevitable. Thus if A (all grasshoppers have six legs) 
 is true, E (no grasshopper has six legs) cannot be true. 
 If A is not true, E may or may not be true, and we do not 
 know which it is. It is unknown. If E is true, A cannot 
 be true, but if E is untrue, A may or may not be true, and 
 
 Diagram of relations between symbolic propositions. 
 
Judgment 49 
 
 we can tell nothing about it. E and A cannot both be 
 true at the same time, but both of them may be untrue. 
 This relation is called the relation of contrary. 
 
 Relations o! Propositions.— Similarly, if I is true, (some 
 grasshoppers have six legs) 0, (some grasshoppers do not 
 have six legs) may or may not be true. We cannot tell 
 which it is, for we know nothing about from the fact 
 that I is true. If 1 is untrue, we know that must be 
 true. If is true, we know nothing about it; it may or 
 may not be true. If is untrue, I must be true. Both of 
 them cannot be untrue at the same time. This differs 
 from the relation between E and A, and is called the rela- 
 tion of sub-contrary. 
 
 If A is true, I must be true ; if A is untrue, I may or 
 may not be true, and we cannot tell which it is. If I is 
 true, we know nothing about A, but if I is untrue, A must 
 necessarily be untrue also. This relation is called the 
 relation of subaltern, and the same relation exists between 
 E and 0. 
 
 Contradictories. — The most important relation is that 
 which exists between A and 0. If A is true (all grass- 
 hoppers have six legs), then (some grasshoppers do not 
 have six legs) is necessarily untrue. If A is untrue, then 
 must of necessity be true. If O is true, A cannot be 
 true, and if is untrue, then A must be true. Both can- 
 not be true or untrue at the same time. If either one of 
 them is true, the other must be untrue, and if either one 
 is untrue, the other must be true. The relation is called 
 contradictory, and of two contradictory propositions one 
 must be true and the other must be untrue. It is this rule 
 that is employed in geometry in making an indirect dem- 
 onstration. The theorem that "If two planes are perpen- 
 dicular to the same straight line they are parallel, is proved 
 
50 The Thinking Process 
 
 by assuming that they are not parallel, and showing that 
 this supposition is not true. Then the contradictory pro- 
 position must be true, and the planes must be parallel. 
 
 DEFINITIONS 
 
 Judgment. — Judgment is the perception of agreement 
 or disagreement between two notions. 
 
 Affirmative Judgment.— Affirmative judgment is the 
 perception of agreement between two notions. 
 
 Negative Judgment. — Negative judgment is the percep- 
 tion of the disagreement between two notions. 
 
 Proposition. — A proposition is the expression of a 
 judgment. 
 
 Predicate. — The predicate is the expression of the 
 notion that is used as the standard of comparison. 
 
 Subject. — The subject is the expression of the notion 
 that is compared with the predicate notion. 
 
 Copula. — The copula is the expression of the judgment 
 itself. 
 
 Universal Judgment. — A universal judgment is a judg- 
 ment of agreement or disagreement throughout the entire 
 extension of the notions compared. It is indicated by all 
 or no. 
 
 Particular Judgment.— A particular judgment is a judg- 
 ment of agreement or disagreement throughout only part 
 of the extension of the notions compared. It is indicated 
 by the word some, or its equivalent. 
 
CHAPTER V 
 
 THE SYLLOGISM 
 
 I call in question any method of reasoning which can be 
 carried on without a knowledge of deductive processes.— Jeoons, 
 Principles of Science, p. 12. 
 
 Every conclusion (syllogistic) like every judgment, is merely 
 an association of ideas. But as a distinct form of association it is 
 almost of no importance psychologically. — Ziehen, Physiological 
 Psychology, p. 229. 
 
 Reasoning is a classification of relations. But what does clas- 
 sification mean ? It means the grouping together of those that are 
 alike. — Spencer, Psychology, Volume II, p. 115. 
 
 The Syllogism. — We purpose to begin our study of 
 reasoning with the syllogism, because it is the simplest 
 and the best understood process. The laws of the syllo- 
 gism were developed by Aristotle, who died 322 B. C, 
 and there has been little improvement made in them since 
 his time. Even if we can show that there are other forms 
 of reasoning, or that syllogistic reasoning is capable of 
 being reduced to other forms, it is still true that we must 
 know what a syllogism is, and the kind of study that has 
 been put upon it. 
 
 Definition and Example.— A syllogism consists of a 
 series of three propositions, two of which are so related 
 to each other that the third one can be derived from 
 them. 
 
 The classical syllogism employed by Aristotle and 
 repeated by every writer on logic since his time is as 
 follows : 
 
 All men are mortal. 
 Socrates is a man. 
 Socrates is mortal. 
 
52 The Thinking Process 
 
 Instead of using this form in which one of the notions 
 is a singular concrete notion, I should prefer to employ 
 our old friend the grasshopper as the subject of the 
 propositions, and use two general abstract notions. Let 
 us examine the following syllogism. 
 
 All insects have six legs. 
 The grasshopper is an insect. 
 The grasshopper has six legs. 
 
 Parts of a Syllogism.—-In this series the third proposi- 
 tion is called the conclusion, because it is derived from 
 the other two. The other two are called the premises, 
 the first of which is the major premise and the second is 
 the minor. It will be seen that the two premises contain 
 two general abstract notions each, but an examination of 
 the notions involved will show that there is one notion, 
 insect, that is found in both of the premises. Instead of 
 being four notions, there are only three. The notion 
 that is found in both premises, expressed by the term 
 insect, is called the middle term, and is designated by the 
 capital letter M. 
 
 Meaning of the Terms.— The major premise contains 
 the middle term, and another which is called the major 
 term. The major term is designated by the letter P, be- 
 cause it is used as the predicate of the conclusion. The 
 minor premise contains besides the middle term another 
 which is called the minor. It is designated by the letter S, 
 because it is used as the subject of the conclusion. The 
 major premise is called the major premise because it con- 
 tains the major term, and the minor premise is called minor 
 because it contains the minor term. The major term is 
 called major because, like the predicate of any other 
 proposition, it has greater extension than the minor term. 
 
The Syllogism 53 
 
 Syllogism A Process of Comparison.— In perception, we 
 perceive resemblances between the qualities of an object. 
 In forming a general abstract notion we perceive resem- 
 blances between singular concrete notions. In making a 
 judgment we perceive resemblances between general 
 abstract notions, although it is not necessary that both 
 notions shall be abstract. In a syllogism, we have a more 
 complex process, and it appears that we ought to say that 
 we compare judgments, although in fact such is not the 
 case. We compare notions in a syllogism just as we do 
 in making a judgment, with this difference, however, that 
 in a judgment, we compare two notions directly with each 
 other, while in a syllogism we compare two notions 
 indirectly by means of a third which is expressed by the 
 middle term. We perceive resemblance between two 
 notions in both judgment and in a syllogism, but in one 
 case we perceive it by a process of direct comparison, 
 while in the other, we perceive it by a process of indirect 
 comparison. 
 
 Axiom. — There is an axiom in mathematics which with 
 a slight change of meaning will apply here. Things that 
 are equal to the same thing are equal to each other. So 
 we may say that notions that are similar to the same notion 
 are similar to each other. The paraphrase is not strictly 
 true, for the similarity to the same notion may exist in 
 different qualities in notions that are compared with it. 
 
 Physiological Interpretation of a Syllogism.— We may 
 picture the physiological process that accompanies 
 the syllogism as follows : 
 
 We may represent the two notions, major and minor, 
 by two circles that do not intersect. We do not compare 
 the notions directly. The nervous impulse will encounter 
 so much resistance that it will not pass readily from one 
 
54 The Thinking Process 
 
 combination into the other. But if we draw a third circle, 
 representing the middle term M so that it shall have a 
 section common to S and M, which we may call x, and 
 another section common to M and P, which we may call 
 y, the nervous impulse may pass from S into M through 
 
 Physiological interpretation of the Syllogism. — Sx is M. Mx is P. 
 
 the common section x, and from M it may pass readily into 
 P by means of the common section y. Thus by means of 
 introducing the middle circle, representing the middle term 
 M, we shall find an easy passage from the center S to the 
 center P. The resistance that would be so great as to 
 prevent the passage directly is diminished to such an 
 extent by going through M by means of the common 
 sections x and y that the nervous impulse passes readily 
 from one to the other. 
 
 Simplicity of the Hypothesis. — While the process as 
 described is altogether hypothetical, and is without doubt 
 much simpler than that which actually occurs, it is in its 
 simplicity comparable to the syllogism itself as a form of 
 reasoning, and will enable us to comprehend the process 
 by means of the physiological image. In fact, it will be 
 found possible to describe reasoning in physiological 
 terms as the concomitant of the process by which we find 
 an easy passage for the impulse from one combination of 
 cells into another that is not directly connected with it. 
 
The Syllogism 55 
 
 Fallacies. — It is very easy to derive a false conclusion 
 from true premises. In fact, it is very difficult to employ 
 the syllogism in a proper way. The wrong kind of 
 reasoning by which a false conclusion is reached is called 
 a fallacy. There are many fallacies and rules to be 
 observed in the employment of the syllogism, and we 
 shall merely indicate some of the most common. 
 
 Undistributed Middle —The first fallacy is called that of 
 the undistributed middle and is illustrated by the following 
 syllogism : 
 
 All insects breathe by spiracles. 
 A centipede breathes by spiracles. 
 A centipede is an insect ; 
 
 which is not true. The difficulty lies in the middle term, 
 expressing the general notion of spiracle breathing. It is 
 not used in either proposition to include everything that 
 breathes by spiracles. In the first proposition the term 
 spiracle breathing includes only those spiracle breathers 
 that are insects, and in the other proposition it includes 
 only those spiracle breathers that are centipedes. So in 
 neither case does it include all spiracle breathers and 
 therefore is said to be undistributed. In the major pre- 
 mise we compare the notion insect with one group of 
 spiracle breathers, and in the other premise we compare 
 the notion centipede with a different group. So, instead 
 of comparing the two notions, insect and centipede, with 
 the same notion, we really compare them with different 
 notions, or different parts of the same notion. Hence in 
 reality we have four terms instead of three. The middle 
 term must always be distributed, and every term that is 
 distributed in the conclusion must be distributed in one of 
 the premises. Distributed means to be used in such a way 
 as to include everything to which the notion belongs. In 
 
56 The Thinking Process 
 
 order that a term may be distributed it must be used as 
 the subject of a universal or the predicate of a negative. 
 
 Illicit Process. — Another fallacy is called the fallacy of 
 the illicit process of the major, which is merely another 
 name for the fallacy of the undistributed major term. The 
 major term is distributed in the conclusion when it is not 
 distributed in the premises. 
 
 All injurious insects should be killed. 
 A cockroach is not an injurious insect. 
 A cockroach should not be killed. 
 
 The conclusion is not true. The major term is " Should 
 be killed ", and it is not distributed in the major premise. 
 There are other things that should be killed besides inju- 
 rious insects. The term is used as the predicate of a uni- 
 versal affirmative, instead of the subject. It is distributed 
 in the conclusion, because it is used as the predicate of a 
 negative. Hence we get an invalid conclusion. 
 
 Particular Premises.— Look at this syllogism : 
 
 Some insects have red wings. 
 
 Some grasshoppers do not have red wings. 
 
 Some grasshoppers are not insects. 
 
 Here the difficulty is not in the undistributed middle nor 
 the major term. The middle is distributed, since it is used 
 as the predicate of a negative. It is true that the major is 
 not distributed in the premise, but there is no way to avoid 
 this when both premises are particular propositions. The 
 rule is that from two particular propositions no conclusion 
 can be drawn. One of the premises must be universal. 
 
 Negative Premises.— 
 
 No insect has ten legs. 
 
 No grasshopper has ten legs. 
 
 A grasshopper is not an insect. 
 
The Syllogism 57 
 
 This illustrates the rule about negative propositions, which 
 is that from two negative premises no conclusion can be 
 drawn. One of the premises must be an affirmative. This 
 fallacy is well illustrated by the conundrum, " Why is an 
 elephant like a wheelbarrow ?" And the answer is, " Be- 
 cause neither of them can climb a tree." 
 
 Ambiguous Middle. — To the fallacy of ambiguous middle 
 belongs the proof that a cat has ten tails. No cat has nine 
 tails. One cat has one tail more than no cat. Therefore, 
 one cat has ten tails. So also we shall be able to see the 
 fallacy in the demonstration that two is equal to zero, that 
 every aspiring beginner in algebra so confidently shows to 
 his teacher. The square root of 1 is 1. The square root 
 of 1 is minus 1. Minus 1 equals plus 1, since things that 
 are equal to the same thing are equal to each other. Add- 
 ing 1 to both members of the equation, shows us that two 
 equals zero. The fallacy lies in the ambiguous middle 
 term. The square root of 1 may be either plus 1 or 
 minus 1. 
 
 It will be seen from the above examples that 
 the syllogism must be applied in the right way to obtain 
 valid conclusions even from correct premises. We have 
 indicated only four or five kinds of fallacies, but it is easily 
 possible to discover twenty or thirty different kinds. 
 
 Figure. — Writers on logic speak of the figure of the 
 syllogism. By this they mean the arrangement of the dif- 
 erent terms in the propositions, or it might be described as 
 the position of the middle term in the two premises. 
 
 The middle term may be used as the subject of both 
 premises, as the predicate of both premises, as the subject 
 of the major and the predicate of the minor, as the predi- 
 cate of the major and the subject of the minor. In the 
 first figure the middle term is used as the subject of the 
 major and the predicate of the minor. 
 
58 The Thinking Process 
 
 First Figure.— 
 
 All insects have six legs. 
 A grasshopper is an insect. 
 A fc^rasshopper has six legs. 
 
 This figure may be represented by the formula MP-SM- 
 SP. 
 
 Second Figure. — In the second figure the middle term 
 is used as the predicate in both major and minor premises. 
 
 All insects have six legs. 
 
 A centipede does not have six legs. 
 
 A centipede is not an insect. 
 
 The formula for this figure may be written PM-SM-SP. 
 
 Third Figure. — In the third figure the middle term is 
 used as the subject of both premises. 
 
 All insects have six legs. 
 
 All insects breathe by spiracles. 
 
 Some spiracle breathers have six legs. 
 
 The formula for this figure may be written MP-MS-SP. 
 
 Some questions may be raised why in our conclusion 
 we say some, making the conclusion particular, while the 
 premises are both universal. If the conclusion were to be 
 universal, we should distribute the minor term in the con- 
 clusion, using it as the subject of an universal, when it is 
 not distributed in the premises, where it is used as the 
 predicate of an affirmative. So we shall find that every 
 figure has its own rules, which must be regarded in order 
 to obtain a correct conclusion. 
 
 Fourth Figure. — In the fourth figure, the middle term 
 is used as the predicate of the major and the subject of the 
 minor premise. 
 
The Syllogism 59 
 
 All insects have six legs. 
 
 A six-legged animal is not a spider. 
 
 A spider is not an insect. 
 
 The formula may be written PM-MS-SP. 
 
 Mood. — Writers on logic also distinguish another 
 property of the syllogism which they call mood. By 
 mood they mean the different kinds of propositions that 
 enter into the syllogism. There are four kinds of propo- 
 sitions, and only three are necessary to make up a syllo- 
 gism. So it would appear at first sight that there are 64 
 possible moods. Sixty-four different arrangements of 
 four letters, A E I 0, may be made using three at a time. 
 There may be sixteen beginning with A, sixteen beginning 
 with E and sixteen each with I and 0. But an examina- 
 tion will show that many of these combinations must be 
 rejected. All those combinations that have E and as 
 the first two must be rejected, because E and represent 
 negative premises. So all combinations that have for the 
 first two letters and I must be rejected, because they 
 represent syllogisms in which both premises are particular. 
 All combinations in which one of the letters represent a 
 negative premise while the conclusion is affirmative must 
 be rejected, as well as all of those in which one of the 
 premises is particular and the conclusion is universal. We 
 shall thus find that there are only ten legitimate moods, 
 which may be expressed by the combinations AAA, EAE, 
 All, EIO, AEE, AOO, AAI, IAI, EAO, OAO. 
 
 Mnemonic Lines. — There is a series of barbarous 
 mnemonic lines that are intended to indicate the moods 
 that are legitimate in each figure. The lines are packed 
 with information most of which it is unnecessary to learn, 
 and it is wholly unnecessary to commit them to memory. 
 The original lines are in Latin, but the only part which it 
 
60 The Thinking Process 
 
 is necessary for us to understand is the series of words 
 which represent the moods. The moods are indicated by 
 the vowels in the words, while the consonants indicate 
 certain operations that may be performed upon the syllo- 
 gisms. The legitimate moods are represented by the words 
 
 First figure — Barbara, celarent, darii, ferio. 
 
 Second figure — Cesare, camestres, festino, baroko. 
 
 Third figure — Darapti, disamis, datisi, felapton, 
 bokardo, ferison. 
 
 Fourth figure — Bramantip, dimaris, camenes, fesapo, 
 fresison. 
 
 Although in these lines there are nineteen different words 
 indicating nineteen moods, there are so many duplications 
 that only ten different combinations of vowels are found. 
 The different moods are recognized by the words in the 
 lines. Thus the mood that contains three universal affir- 
 mative propositions is always known as the mood barbara. 
 So when we wish to indicate the mood in the fourth 
 figure that has both of its premises universal affirmative 
 and its conclusion a particular affirmative, we always 
 speak of the mood bramantip. 
 
 This discussion will show something of the nature of 
 the study that has been put upon the syllogism. The 
 importance of the syllogism as a method of reasoning is 
 not very great; but it furnishes us an easy introduction 
 into the reasoning process, and the real nature of the 
 psychological movement upon which reasoning depends. 
 
 DEFINITIONS 
 
 Syllogism. — A syllogism is a series of three proposi- 
 tions, two of which are so related to each other that the 
 third may be derived from them. 
 
The Syllogism 61 
 
 Conclusion. — The third proposition in the syllogism. 
 
 Premises. — The two propositions other than the con- 
 clusion. 
 
 Middle Term. — The middle term is the one that occurs 
 in both premises. 
 
 Major Term. — The major term is the predicate of the 
 conclusion. 
 
 Minor Term. — The subject of the conclusion. 
 
 Major Premise. — The premise that contains the major 
 term. 
 
 Minor Premise. — The premise that contains the minor 
 term. 
 
 Fallacy. — An error in reasoning by which a false con- 
 clusion is drawn. 
 
 Illicit Process. — That fallacy that arises from the major 
 term's being distributed in the conclusion when it is not 
 distributed in the premise. 
 
 Undistributed. — Used in a manner that does not indi- 
 cate the full extent of its signification. 
 
 Figure. — That property of the syllogism that designates 
 the position of the middle term in the premises. 
 
 Mood. — That property of the syllogism that designates 
 the kind of propositions which constitute it. 
 
CHAPTER VI 
 
 DEDUCTIVE AND INDUCTIVE REASONING 
 
 The sense of sameness is the very keel and backbone of our 
 thinking.— James Psychology, Volume I, p. 459. 
 
 Science arises from the discovery of identity amidst diversity. 
 — In every act of inference, or scientific method we are engaged 
 about a certain likeness, identity, sameness, similarity, resemblance, 
 analogy, equivalence, or equality apparent between two objects. — 
 Jevons, Principles oj Science, p. / . 
 
 By no inductive process can we prove the universal. But 
 reason, assuming the uniformity of thought, universalizes the 
 uniformity of nature. — Lloyd Morgan, Comparative Psychology, p. 285. 
 
 The uniformity of nature is a condition of all mental develop- 
 ment, as of all reasoning; but it is not conceived as a condition until 
 reason is firmly seated on her throne. — Lloyd Morgan, Comparative 
 Psychology, p. 285. 
 
 This principle (of identity) , is therefore the highest form of 
 thought, the postulate on which all science depends. The relation 
 of similarity underlying all association of ideas is expressed by the 
 principle of identity in an ideal and absolute form which our actual 
 associations attain at best only approximately. — Hoffding, p. 177. 
 
 Limitations of the Syllogism.— The syllogism has some 
 very serious limitations, that largely diminish its useful- 
 ness. In the first place, not all forms of reasoning are 
 capable of being reduced to the syllogistic form. I look 
 up at the sun and say that the sun dazzles my eyes. Or 
 I lay a lath between two tables and propose to walk across 
 it. The reasoning process by which you arrive at the 
 conclusion that the lath will break and precipitate me to 
 the floor is enormously complex; too complex ever to be 
 reduced to the form of a syllogism. Even if we were to 
 undertake to reduce the demonstration of a simple 
 theorem in geometry to a series of syllogisms, we should 
 find that the process is very long and difficult to accom- 
 plish. 
 
 - 
 
Reasoning 63 
 
 Fallacies. — In the second place, it is difficult to avoid 
 fallacies in making use of syllogistic reasoning. Some 
 kinds of fallacies are difficult to detect. In the preceding 
 chapter we have mentioned five kinds, but it would be 
 easy to extend the list to twenty-five. We can seldom 
 affirm that we have avoided every possible fallacy, and 
 must always assert the validity of our conclusion subject 
 to the qualification "If we have avoided all fallacies." 
 
 Not Affirm Truth of the Premises.— The third limitation 
 is that the syllogism does not affirm anything about the 
 truth of the premises. All that it does affirm is that if 
 the premises are true and all fallacies are avoided, then 
 the conclusion is true. But the test of the truth of the 
 premises must be made by some other means than by the 
 syllogism itself. 
 
 Not Discover The Premises.— The fourth limitation is 
 somewhat like the third. The syllogism does not enable 
 us to obtain the general truths that are used as the 
 premises in any train of reasoning. We must have the 
 general truths, one of which at least must be universal, 
 but there is no way in which they may be obtained by 
 syllogistic reasoning. This in itself shows that the syllo- 
 gism is not an all-sufficient form of reasoning. 
 
 A fifth limitation is that the syllogism does not dis- 
 close any new truth. Everything that is affirmed in the 
 conclusion has already been stated in the premises. When 
 I have said that all insects have six legs, I have stated the 
 fact already about the grasshopper. The conclusion is 
 already involved in the premises. 
 
 One Advantage. — The one advantage of the syllogism 
 is that it discloses truth that is involved in the premises 
 when we should not discover that it is there unless it 
 were disclosed by such a process. The truth that the 
 
64 The Thinking Process 
 
 surface of a sphere is equal to the area of four great 
 circles is involved in the definition of a sphere, a circle, 
 and two or three other definitions and axioms ; but we 
 should never discover the truth in these definitions and 
 axioms if it were not for the process of reasoning. 
 
 Deductive Reasoning. — Syllogistic reasoning was re- 
 garded, from the time of Aristotle down to the time of 
 Francis Bacon, as the only form of reasoning. It was 
 believed that the mind always reasoned syllogistically and 
 that if we wished to do so, all processes of reasoning 
 could be reduced to the syllogistic form. Francis Bacon 
 described a different form of reasoning which is called 
 induction. The syllogism is the best example of deductive 
 reasoning. 
 
 Inductive Reasoning. — Deductive reasoning begins 
 with general truths and reasons to a particular conclu- 
 sion. The premises with which we start are always wider 
 than the conclusion. It is a process of reasoning from 
 the general to the particular. Inductive reasoning starts 
 with the particulars and reasons to the general. The 
 premises are never so wide as is the conclusion. 
 
 If I wish to discover the general truth that all insects 
 have six legs, I begin with particular individuals. I 
 examine an insect and count the number of its legs. 
 Then I examine as many more insects as I can, and per- 
 haps induce all my friends to examine and report the 
 number of legs that they discover on insects. Suppose 
 that I and my friends have counted the number of legs on 
 a hundred thousand insects, then from this I reach the 
 conclusion that all insects have six legs. 
 
 One Limitation. — There is one limitation on inductive 
 reasoning as it is here described, and that is that there is 
 
Reasoning 65 
 
 no way of being certain that after having counted the 
 number of legs on a hundred thousand insects, the very 
 next insect examined may have not six but eight, or four, 
 or some other number. The sun has always risen in the 
 east, but there is no necessary connection, so far as the 
 reasoning process can discover, that will make it impos- 
 sible for it to rise in the north or west tomorrow. So 
 inductive reasoning cannot assert absolute certainty. 
 
 Complete Induction. — There is one process by which 
 absolute certainty may be attained, and that is by a pro- 
 cess of complete induction, in which every particular is 
 examined. The earth has only one moon. Everything 
 that by any possibility might be a moon has been examined, 
 and only one has been found. There is no student in 
 school that is more than 150 years old. Every student 
 has been examined in this respect. There is no building 
 in Ypsilanti that is 13 stories high. Every building has 
 been examined. In this way absolute certainty can be 
 obtained. 
 
 Not Reasoning'. — There are two things to be said about 
 complete induction. One of them is that it is not a form 
 of reasoning at all, and does not differ from direct obser- 
 vation. The other limitation is that there is no gain by 
 such a reasoning process. The conclusion is no wider 
 than the premises. So all the gain and the increase in 
 knowledge that we can acquire in reasoning must come 
 from incomplete induction. 
 
 Suppose that I have examined a hundred thousand 
 insects, and have found that all of them have six legs. I 
 reason from this to the general conclusion that all insects 
 have six legs. The conclusion is wider than the premises. 
 
66 The Thinking Process 
 
 How Reach Inductive Conclusion.— The process by 
 which this conclusion is reached may be clearly stated in 
 the following series of propositions : 
 
 All insects that I have examined have six legs. 
 
 All insects are like those that I have examined. 
 
 All insects have six legs. 
 It will be seen that this train of reasoning takes the form 
 of a syllogism of which the major premise is a complete 
 induction, all insects that I have examined have six legs. 
 The minor premise is an assumption without any positive 
 evidence of its truth, and this is the possible source of 
 error. The conclusion is derived from these two premises. 
 
 The Premises.— In the first premise, "All insects that I 
 have examined " is the middle term. The major term is, 
 " Have six legs." In the minor premise the minor term is 
 "All insects." We see that the syllogism contains three 
 propositions, all of them universal affirmative. It is a syl- 
 logism of the first figure and of the mood barbara, and we 
 shall find that the first figure of the syllogism is involved 
 in every process of inductive reasoning. 
 
 Uniformity of Nature. — Every process of inductive rea- 
 soning involves this deductive process. The minor premise 
 is obtained by assuming the uniformity of those things that 
 we have not examined with those things that we have 
 examined. Putting it in very general terms, we may say 
 that every induction involves an assumption of the uni- 
 formity of nature. I believe that the sun will rise tomor- 
 row, for my total experience has been that it has risen 
 every morning. It has always risen in the east, and it is 
 easy for me to believe that it will rise in the east again, 
 although there is nothing in the nature of my reasoning 
 process that would compel me to assent to the proposition 
 that it might not rise in the west tomorrow. If any one 
 
Reasoning 67 
 
 choses to assert that it will rise in the west tomorrow 
 morning, and challenge me to prove that it would not, 
 although I might suspect his sanity, I should be compelled 
 to reply, " Let us wait and see." 
 
 Origin of Intuitive Ideas.— The fact that every insect 
 that I have examined has six legs makes it easy for me to 
 believe that every other insect, when it is examined, will 
 be found to have six legs, and it is easy for me to make 
 the assumption without having examined every particular. 
 The experience of our ancestors with certain things has 
 been just like our own, and has probably contributed to 
 our readiness to assume the truth of the axioms of mathe- 
 matics, and the things that were designated by former 
 psychologists as intuitive ideas and necessary self-evident 
 truths. 
 
 Superstitions.^-No reasoning process is possible with- 
 out this belief in the uniformity of nature, and yet our 
 belief in such uniformity is not very strong. When we 
 overturn the salt cellar, we throw a pinch of salt over our 
 shoulder. This implies that we do not believe that things 
 will go on as they did before we overturned the salt cellar. 
 So we knock on wood, refuse to turn back when we have 
 forgotten something, hang a snake on the fence, watch for 
 the moon over our right shoulder. These things imply a 
 belief in the fact that nature is not uniform, but that some- 
 thing may constantly interfere to change the course of 
 natural events. It really involves the kind of fallacy that 
 is called irrelevant conclusion. In case of these supersti- 
 tions, there is not the necessary connection between our 
 actions and the events they are supposed to influence that 
 We assume that there is. 
 
 Insufficient Number of Particulars.— One serious error 
 in making an induction is the failure to examine a suffi- 
 
68 The Thinking Process 
 
 cient number of particulars to avoid a wrong assumption. 
 We assume a uniformity of the things that we have not 
 seen with the things that we have seen, when an examina- 
 tion of a larger number of particulars would show that 
 they are not similar. Thus the square of three is nine and 
 the square of four is sixteen. The sum of nine and six- 
 teen is twenty-five, which is a perfect square. So the 
 square of six is thirty-six and the square of eight is sixty- 
 four. The sum of thirty-six and sixty-four is one hundred, 
 which is a perfect square. The sums of all squares that I 
 have examined are perfect squares ; the sums of all squares 
 are like those that I have examined ; therefore the sum of 
 any two squares will be a perfect square, which is not true. 
 An examination of sufficient number of particulars will 
 enable us to avoid such mistakes. 
 
 Induction and Deduction Inseparable.— The conclusion 
 obtained by inductive reasoning is a general truth that 
 may be used as the major premise in a syllogism or other 
 form of deductive reasoning. Thus we see that every 
 deduction demands a previous induction, and we have also 
 seen that every inductive conclusion is reached by a deduc- 
 tive process, so that deduction and induction cannot be 
 separated, but must always go along together. In fact, 
 there are not two processes, but a single process. Writers 
 on logic are now inclined to talk about the deductive-in- 
 ductive process, but it appears that we may make a more 
 nearly accurate analysis of the entire process. In deduc- 
 tion, we perceive the resemblance between two notions, 
 and in induction we perceive the resemblance between the 
 particulars from which the notion is derived. The two 
 processes are identical in the fact that they both consist in 
 the perception of resemblance, and this is the fact that 
 connects reasoning with all other forms of the intellectual 
 
Reasoning 69 
 
 process. Reasoning is merely a complex form of resimila- 
 tion, as judgment and generalization are simpler forms. 
 We already have a physiological interpretation for the 
 process of resimilation, and so find it possible to think of 
 reasoning in physiological terms. 
 
 DEFINITIONS 
 
 Deduction. — A process of reasoning from generals to 
 particulars. The syllogism is the most typical form of 
 deductive reasoning. 
 
 Induction. — A process of reasoning from particulars 
 to generals. 
 
 Complete Induction. — A process of drawing a conclusion 
 from an examination of every particular. 
 
 Incomplete Induction. — A process of drawing a uni- 
 versal conclusion from an examination of only a part of 
 the particulars. 
 
CHAPTER VII 
 
 OTHER FORMS OF REASONING 
 
 Knowledge is impossible without hypotheses.-— f/aecfc/, 
 Wonders of Life, p. 86. 
 
 To make hypotheses, to verify them by experiment, then to 
 connect by the aid of generalizations the facts discovered, rep- 
 resents the stages necessary for the building up of all our knowledge. 
 — LefBon, Evolution of Matter, p. 317. 
 
 It is only in the present century that physicists have begun to 
 recognize this truth (i. e., that while science was supposed to be 
 advancing by the Baconian method, hypothetical investigation was 
 the real instrument of progress) . So much opprobrium had been 
 attached by Bacon to the use of hypotheses that we find Young 
 speaking of them in an apologetic tone.— Jevons, Principles of Science, 
 p. 508. 
 
 Among uncultivated observers, the tendency to remark the 
 favorable and to forget the unfavorable events is so great that no 
 reliance can be placed upon their supposed observations.— Jevons, 
 p. 402, 
 
 All science starts with hypothesis. — Huxley, Hume, p. 65. 
 
 Since perception rests upon a process that may be described 
 as involuntary comparison, it manifests itself as an activity of 
 thought by means of which we appropriate what is given in the 
 sensation, incorporate the sensation into the content of our con- 
 sciousness. — Hoffding, p. 130. 
 
 Analogy. — In deduction we begin with the general 
 and reason to the particular ; we begin with the many 
 and reason to the one. In induction we begin with the 
 particular and reason to the general ; we begin with the 
 one and reason to the many. If we reduce the many that 
 we begin with in deduction, and reduce the many that we 
 reason to in induction, we shall ultimately approximate a 
 condition in which we reason from one to one. Whether 
 
Forms of Reasoning 71 
 
 this one that we begin with is the general of deduction or 
 the particular of induction may be a question; and 
 whether the one that we reach in the conclusion is the 
 particular of deduction or the general of induction is also 
 difficult to determine. By this process, however, we are 
 able to show that deduction and induction are the same 
 process. It is a process of reasoning from particular to 
 particular, as described by John Stuart Mill, and which 
 Jevons asserts is not a form of reasoning at all. It ap- 
 pears, however, not only to be a form of reasoning, but 
 the most common form. It is a special form of induction 
 which we may call analogy. 
 
 Differs From Baconian Induction. — The very name 
 analogy implies the perception of resemblance. In 
 reasoning by analogy we begin with a particular, and this 
 is sufficient to indicate that reasoning by analogy is a form 
 of induction. The difference however, is that in the 
 typical Baconian induction, we begin with the largest 
 number of particulars that we can get. In analogy, we 
 do not try to secure the largest number of particulars, 
 but, in the most common examples, we begin merely with 
 one, and reason to the many, or the universal. 
 
 Analogy is a valid form of reasoning and is the most 
 common form of the reasoning process that we employ. 
 It leads to valid conclusions if we observe the proper 
 precautions. It is by this process that the larger number 
 of our daily actions are determined. When I find the 
 thermometer at my house flirting with the zero mark, I 
 do not need to make an examination of as many 
 thermometers as possible in order to come to the conclu- 
 sion that I shall not find balmy zephyrs blowing around 
 the normal school building. I do not need to observe the 
 ice in the pond, the hardness of the ground, the other 
 indications of frost of as many different kinds as possible, 
 
72 The Thinking Process 
 
 to come to the decision that it is cold. When I start out 
 and find one crossing is muddy, I do not need to examine 
 all other crossings in town to induce me to go back and 
 get my rubbers. I reason from the one particular that all 
 other crossings are likely to be muddy. So when I find it 
 raining at my house, I reason from this one particular that 
 it is raining in every other place in town, and get my 
 umbrella. 
 
 Deductive Process In Analogy.— Like every other form 
 of induction, analogy involves a deductive process. My 
 reasoning is as follows : This crossing is muddy. Every 
 crossing in town is like this crossing. Every crossing is 
 muddy. The mistake may occur in the second, minor, 
 premise. It may be that not all other crossings in town 
 are like this crossing, and my reasoning will lead me to a 
 wrong conclusion. 
 
 Analogy In Geometrical Demonstration.— In geometry 
 we employ the same process of reasoning. We have 
 described the demonstrations in geometry as among the 
 best examples of deductive reasoning, but there is also 
 employed in them an inductive process which is that form 
 that we have called analogy. When I have proved that 
 in one triangle the three angles are equal to two right 
 angles, I do not have to demonstrate it for as many tri- 
 angles as I can draw, and as many as I can get my friends 
 to draw. I reason from this one particular triangle to the 
 general conclusion that the sum of the angles of all 
 triangles is equal to two right angles. My minor 
 premise is that All triangles are like this triangle, and if 
 this premise is true my conclusion is a valid one. 
 
 Fallacies In Analogy. — But sometimes the analogy does 
 not involve any necessary connection between the things 
 observed and others that are assumed to be like it. There 
 
Forms of Reasoning 73 
 
 was a Mohammedan doctor who always prescribed a 
 white medicine for a chill, red medicine for fever, and 
 yellow medicine for jaundice. Similarly the story is told 
 of a negro physician who when called upon to treat a case 
 of hemorrhage of the lungs prescribed a dose of mustard 
 and a dose of mucilage. He explained this system of 
 therapeutics by saying that he wanted the mustard to 
 draw the parts together and the mucilage to make them 
 stick. When the planet Uranus was discovered, there 
 were learned men who gravely argued that there could be 
 no such planet as Uranus. There were only seven days 
 in the week, only seven metals, seven colors in the rain- 
 bow, seven intervals in the octave, and consequently 
 there could be only seven planets. As there were five 
 already known, the number with the earth and moon was 
 complete, and no other planet was possible. The diffi- 
 culty with this reasoning was that there was no necessary 
 connection between the seven days in the week and the 
 seven planets. 
 
 Origin of Superstitious Beliefs.— Many common beliefs 
 rest upon the evidence of analogy observed in a single 
 particular, and contradictory instances are neglected. If 
 it should rain on Easter Sunday it will rain for the 
 succeeding seven Sundays. One time in boyhood, the 
 writer observed this occurrence, and he has had a mild 
 form of belief that it will always happen so. Potatoes 
 planted in the light of the moon will all go to tops. A 
 cloud coffin seen in the sky foretells the death of some 
 one in the family. A bell ringing in one's ears indicates 
 the same kind of disaster. A dog howling at night indi- 
 cates a death, although in case of the writer, it is more 
 likely to be the death of the dog. Most of such beliefs 
 have probably arisen somewhere by the observation of a 
 single instance, and the general conclusion has been 
 
74 The Thinking Process 
 
 drawn. The only way to avoid such errors in reasoning 
 is to look for the evidence of a necessary connection, and 
 to examine a number of particulars, as well as to be 
 especially watchful for contrary instances. 
 
 Limitations of Analogy.— Sometimes an analogy will 
 hold for a few instances and then break down. An 
 equation containing one unknown quantity may be 
 represented by a straight line. An equation containing 
 two unknown quantities may be represented by a curve, 
 enclosing a surface. An equation containing three un- 
 known quantities, requires a solid to represent it. What 
 would represent an equation containing four unknowns ? 
 But it is from a consideration of such analogies that we 
 derive our pseudo notion of a fourth dimension of space. 
 A moving point will generate a line ; a moving line will 
 generate a surface, a moving surface will generate a solid, 
 but what will a moving solid generate ? The analogy 
 breaks down at this point. 
 
 Hypothesis. — Analogy is principally useful in suggest- 
 ing a probable truth. By means of analogy we may make 
 a guess at what a truth may be. We may act upon this 
 probable truth, or if the case is an important one and does 
 not demand immediate action, we may proceed to verify it. 
 This leads us to the form of reasoning that is called hypo- 
 thesis. Hypothetical reasoning begins with an examina- 
 tion of particulars, just as does any other form of induction ; 
 but in the typical Baconian induction we examine as many 
 particulars as possible and draw our conclusion, with which 
 the process stops. In hypothesis, we do not employ 
 as many particulars as possible, but only a sufficient num- 
 ber of the most significant. A small number of particu- 
 lars, as unlike as possible, will be more serviceable in 
 framing a hypothesis than a larger number of concordant 
 examples. When we have drawn our conclusion from the 
 
Forms of Reasoning 75 
 
 particulars considered, we have merely formed the hypo- 
 thesis, from which we proceed to reason. The termination 
 of the induction is merely the first step by which the truth 
 is established. 
 
 Second Step in Proof. — The hypothesis must agree with 
 all the observed particulars. The second step is the col- 
 lection and examination of new particulars. If all the new 
 particulars which are discovered and examined fit into the 
 hypothesis and none of them contradict it, then we have 
 another reason for believing that it is true. The hypo- 
 thesis was formed before the new particulars were exam- 
 ined, and the fact that they fit into it is rather strong evi- 
 dence of its truth. It is somewhat like the stories of two 
 witnesses who have not consulted with each other. If 
 neither knows what the other has told, the evidence is 
 stronger than if they have consulted with each other and 
 each has heard what the other has said. 
 
 Third Step. — The third step in the verification of an 
 hypothesis is a process of deductive reasoning. Assuming 
 that the hypothesis is true, we may use it as a major 
 premise and reason backward to the particulars. If the 
 particulars that we reach by our process of deductive rea- 
 soning correspond to the particulars that we observe, then 
 our hypothesis is assuming a high degree of probability. 
 When Newton proposed his hypothesis of gravitation, he 
 proceeded to test it deductively. His hypothesis was that 
 the moon, like other bodies, falls toward the earth with a 
 velocity proportional directly to the mass and inversely as 
 the square of the distance. He knew, or thought he knew, 
 the size and mass of the earth, and the distance that it was 
 from the moon. His calculations showed that the moon 
 ought to fall toward the earth at the rate of thirteen feet 
 a second, when direct observation showed that it did fall 
 
76 The Thinking Process 
 
 at the rate of fifteen feet a second. The discrepancy was 
 too great, and he abandoned his hypothesis. He laid his 
 papers away, and thirteen years afterward, learning of a 
 new measurement of the earth, he introduced this new 
 value into his calculations, and found that the calculated 
 distance agreed exactly with the observed distance. This 
 agreement testified very strongly in favor of the hypothe- 
 sis, and gave it a high degree of probability. 
 
 Fourth Step, Prediction.— But there is a fourth step in 
 the verification of an hypothesis. Assuming that the 
 hypothesis is true, we may predict that other things are 
 true, and search for those particulars which would not 
 likely be found, if it were not for the hypothesis. If we 
 can verify our predictions made from the hypothesis, we 
 have approximated the demonstration of its truth as nearly 
 as it is possible to demonstrate the truth of anything. 
 There is no higher test of the truth of a general principle 
 than this. 
 
 Newton's theory of gravitation has led to many veri- 
 fied predictions of this kind. After the planet Uranus was 
 discovered, an orbit was calculated for it according to the 
 laws of gravitation. In a few years the planet failed to 
 move accurately in the orbit. Either the law of gravita- 
 tion was not true, or there was some other cause for the 
 variation from the orbit. Accordingly, an English mathe- 
 matician, Adams, and a French astronomer, Leverrier, 
 undertook to calculate the size, position and distance of a 
 planet outside the orbit of Uranus that should account for 
 its deviation. Leverrier on the very night that he finished 
 his calculation wrote to his friend, Dr. Galle, in Berlin, 
 telling him to point his telescope at a particular spot, and 
 he would see a star of the eighth magnitude, which would 
 be a new planet, never before seen. On the very evening 
 
Forms of Reasoning 77 
 
 that he received the letter, Dr. Galle, following the direc- 
 tions of Leverrier, saw the planet. This discovery furn- 
 ished the highest possible evidence of the truth of the 
 theory of gravitation. Marconi's discovery of wireless 
 telegraphy came as a prediction based upon the theory of 
 electric waves in ether. 
 
 Examples of Hypothesis.— The theory of planetary 
 orbits, Kepler's laws, the atomic theory of matter, the 
 kinetic theory of gases, theory of light, luminiferous ether, 
 evolution, or the derivative origin of species are all 
 examples of discoveries made by hypothetical reasoning. 
 We are sometimes told that the doctrine of evolution is 
 merely a hypothesis, and has never been satisfactorily 
 demonstrated. This is true, but no other theory, not even 
 Newton's theory of gravitation, has furnished one one- 
 hundredth as many examples of verified predictions as 
 has the theory of evolution. Our hypothesis of the 
 nervous current with its psychological concomitant for 
 each element is another example of hypothetical reason- 
 ing. We cannot say that it has been demonstrated, but 
 if we find new phenomena that are explained by it, and if 
 we are able to predict and to make psychological dis- 
 coveries by means of it, and find nothing to contradict it, 
 it will reach a high degree of probability. When it fails 
 to do this, we must discard it, and substitute another 
 theory. 
 
 Validity of Hypothetical Reasoning.— By hypothetical 
 reasoning we can more nearly approximate certainty than 
 by any other process of reasoning whatever. Every 
 great discovery in science has been made in this way. 
 Notwithstanding the great admiration that has been 
 expressed for Baconian induction, no great discovery has 
 ever been made by means of it. The observation of 
 
78 The Thinking Process 
 
 additional instances according to the Baconian system 
 adds to the probability of the truth of the conclusion in 
 an arithmetical progression. Thus, for every series of x 
 instances we may express the probability of the truth of 
 the Baconian conclusion as x plus x plus x plus x, which 
 equals 4x. By means of the four lines of proof offered 
 for hypothesis, we may have the product of four factors 
 x times x times x times x, or x 4 . Hypothesis may not 
 attain a result so certain as complete induction, but com- 
 plete induction is not reasoning. 
 
 Classification. — Classification is another form of 
 reasoning. When we classify any object we put it into a 
 class that has already been formed. Suppose that we are 
 called upon to classify a plant. I examine it and find that 
 it has all the characters that constitute the general ab- 
 stract notion of Ambrosiaceae, or ragweed family. I 
 classify it in that family. The reasoning process is as 
 follows : 
 
 x characters constitute my notion of Ambrosiaceae. 
 
 This plant has x characters. 
 
 This plant is an Ambrosiaceae. 
 Such seems to be the process involved in every act of 
 classification, and it demands that we know a good deal 
 about the objects classified. The importance of this 
 process in education is frequently overlooked and mis- 
 understood. It involves, of course, a deductive process, 
 and it is essentially and necessarily a perception of 
 resemblances between the thing classified and the general 
 abstract notion that constitutes the class in which we 
 place it. 
 
 Recognition. — Recognition involves a reasoning pro- 
 cess. Whenever we recognize a person or a thing as 
 something that has been before seen or heard of or read 
 
Forms of Reasoning 79 
 
 about, we do it by a process of reasoning. I saw a man 
 with a peculiar helmet shaped hat riding a bicycle down 
 the street. Half an hour afterward I saw a man riding a 
 bicycle up another street with the same helmet shaped 
 hat. I arrived at the conclusion that it was the same man. 
 The recognition of the hat was immediate. The recogni- 
 tion of the man as the same man necessitated a process 
 of reasoning. The process is a complex one, perhaps too 
 complex to be stated in the form of a syllogism. The 
 major premise involved the immediate recognition of the 
 hat, or some other characteristic. The minor premise in- 
 volves the assumption that the hat, or other character 
 recognized directly is associated with the same characters 
 that it was associated with before. Then the conclusion 
 is drawn that this is the same man. 
 
 Naming. — Naming, or giving a name to an object, in- 
 volves a reasoning process. A little girl was precocious 
 with her needle. She made doll dresses and was 
 acquainted with the details of ladies' costume. She went 
 out of the house and brought in a ball of snow, which she 
 had scraped off the ledge above the base board. Some 
 one said, "Alice, where did you get the snow ? " "O, I got 
 it off the tuck of the house." She applied the word tuck 
 to the ledge, thus giving it a name, and indicating that 
 she perceived a resemblance between this feature of the 
 architecture of the house and the character of a lady's 
 dress to which the name tuck was applied. Whenever 
 we give a name to anything we go through the same 
 kind of a process. 
 
 Reasoning Process in Apperception.— Such examples as 
 the one given above are usually employed to illustrate 
 the process which is called apperception, and it shows 
 very clearly what reasoning process is involved in apper- 
 
80 The Thinking Process 
 
 ception. But apperception is practically only a complex 
 form of perception. It is the sum of all the sensations, 
 both faint and vivid that enter into the percept of an ob- 
 ject, with all the related ideas. The perception of the 
 relation is the essential element in reasoning, so that we 
 may describe apperception as a reasoning process. 
 
 Reasoning Process in Perception. — But naming itself is 
 scarcely more than perception, and perception involves 
 the perception of resemblance between the qualities of an 
 object. Hence in our most complex process of reasoning 
 we are brought back again to the process of perception. 
 In every process of reasoning we have found that there is 
 the same deductive process, and we shall not be surprised 
 to find in the process of perception itself an exemplifica- 
 tion of the first figure of the syllogism, of the mood bar- 
 bara. 
 
 These qualities constitute the apple. 
 
 My sensations correspond to these qualities. 
 
 My sensations correspond to the apple. 
 
 Similarity of All Intellectual Processes.— While the pro- 
 cess of reasoning is very complex, and the complexity is 
 indicated by our employment of the words constitute and 
 correspond, it is possible to show that the process of reason- 
 ing and the process of perception involve the same essen- 
 tial elements. So the point at which we have arrived is 
 our study of the most complex processes of the intellect 
 is the point from which we started. The whole intellec- 
 tual process in all its degrees of complexity resolves itself 
 into the one process of resimilation, or perception of re- 
 semblance, and we have a physiological interpretation for 
 that. The perception of resemblance is the concomitant 
 of the transmission of an impulse through the brain cells 
 that are common to two or more cell combinations. 
 
Forms of Reasoning 81 
 
 DEFINITIONS 
 
 Analogy. — A process of reasoning from a single in- 
 stance to a general conclusion. 
 
 Hypothesis. — A tentative inductive conclusion : A pro- 
 cess of reasoning by which we verify an inductive conclu- 
 sion. 
 
 Classification. — A process by which we group an object 
 with those that are like it. 
 
CHAPTER VIII 
 
 THE THINKING PROCESS. 
 
 There are every year works published whose contents show 
 them to be by real lunatics. " : - * Take the obscurer passages from 
 Hegel : It is a fair question whether the rationality included in them 
 be anything more than the fact that the words belong to a common 
 vocabulary, and are strung together on a scheme of predication and 
 relation, immediacy, self-relation, and what-not, that has habitually 
 recurred. Yet there seems no reason to doubt that the subjective 
 feeling of the rationality of these sentences was strong in the writer 
 as he penned them, or even that some readers by straining may 
 have reproduced it in themselves.— James, Vol. I, p. 264. 
 
 The sense of our personal identity is exactly like any one of 
 our other perceptions of sameness among phenomena.— James, Vol. 
 I, p. 334. 
 
 From our preceding remarks it seems that the nature of mind 
 is its behavior generalized. — Baldwin, Development and Evolution, p. 274. 
 
 In the unity which embraces and holds together the different 
 ideas and sensations and makes their interaction possible, lies the 
 germ of the conception of the ego, or the self. — Hoffding, p. 136. 
 
 Thinking. — Thinking is the process of perceiving rela- 
 tions, and we have seen that every relation may be reduced 
 to the single form of resemblance. Thinking, then, is 
 reduced to the process of perceiving resemblances. Every 
 form of thinking may be reduced to this process, and the 
 one common element is found in all. We have described 
 the forms that have been recognized under the names of 
 judgment, reasoning, generalization, and we might include 
 under the same head, perception in its simplest forms. 
 But some examples of thinking that are not commonly 
 recognized as reducible to either of these forms remain to 
 be discussed. 
 
The Thinking Process 83 
 
 Humor.— In every form of wit or humor will be found 
 this same element of perception of resemblance. A pun 
 is sometimes called the lowest form of humor, and it de : 
 pends wholly for its force upon the resemblance between 
 the forms of two words, whose meanings are generally 
 incongruous. While the humor, or fun, is a feeling, it is 
 one that accompanies a thinking process, and a resem- 
 blance must always be perceived. The point of the joke 
 is in the perception of resemblance, and if the resemblance 
 is not perceived, the point is lost, and the funny feeling is 
 not experienced. 
 
 Poetry. — True poetry is an expression of the highest 
 form of thinking. A true poet is one who perceives the 
 relations existing between ideas which an ordinary person, 
 who is not a poet, will fail to discover, and may reach only 
 by a laborious and round-about process of reasoning. 
 These resemblances the poet perceives by a " flash of in- 
 spiration," or " poetical insight." This flash of genius, or 
 fire of inspiration has never been sufficiently recognized 
 nor analyzed nor associated with other processes. It con- 
 sists essentially in the perception of relations which do not 
 appear to the ordinary man. In this respect the poet is 
 like the great mathematical geniuses, or mathematical 
 prodigies who make calculations with lightning-like rap- 
 idity, involving the instantaneous perception of relations 
 that are Worked out with difficulty by the ordinary man. 
 To Newton, in his eighteenth year, the theorems of Euclid 
 appeared to be self-evident, although most of our high 
 school students arrive at the conclusions only by a diffi- 
 cult process of reasoning. 
 
 Genius. — Genius of any kind is manifested by the per- 
 ception of relations that the non-genius can comprehend 
 only by repetition, slow reasoning, and a long process of 
 
84 The Thinking Process 
 
 thinking. The genius reaches the same goal by direct 
 route, across lots, that the ordinary non-genius must reach 
 by a roundabout journey. So the true poet, like any other 
 genius, is an example of the highest kind of thinking. 
 
 Belie!. — Belief arises whenever the relations are 
 clearly perceived. The purpose of reasoning is to lead to 
 the perception of relations; but reasoning is not more 
 likely to induce belief than is any other process by which 
 the relations are clearly perceived. Reasoning has already 
 been described as the psychological concomitant of the 
 process by which a nervous impulse is caused to pass 
 from one brain center into another with which it has no 
 cells in common. It makes no difference by what method 
 the impulse is caused to pass ; if the pathway connecting 
 the two centers is sufficiently free, then belief arises. 
 The similarity is perceived. In youth, when the cells are 
 growing and sending out dendrites, and changing their 
 shape and opening up connections with other cells, it is 
 easy to direct the impulse from one center into another, 
 with which in after years the connection would be made 
 with difficulty. This is the psychological and physiologi- 
 cal explanation of the fact that early teachings result in 
 beliefs that can seldom be modified or overthrown. 
 
 Belief From Repetition.— Repetition will ultimately 
 occasion belief, if the contradictory idea is inhibited, or 
 does not arise. If the thing is asserted a sufficient 
 number of times, belief will inevitably follow. No argu- 
 ment is so convincing as bald assertion, if the assertion is 
 made a sufficient number of times, and the contradictory 
 idea is prevented from arising. This is the psychological 
 principle that lies at the foundation of advertising- 
 Nothing would seem 4p be more foolish than to repeat the 
 same assertion time after time, but each repetition pro- 
 
The Thinking Process 85 
 
 duces its effect. Association by coexistence will become 
 as powerful, ultimately, as any other form of resemblance. 
 Given a sufficient number of trials the nervous impulse 
 will pass from one brain center to another, no matter how 
 remote they may be, nor how great the resistance between 
 them is. 
 
 Belief From Attention.— Attention is the process by 
 which a nervous impulse may be directed. Resistance 
 may be increased in one direction and diminished in 
 another. Thus attention may hasten the effect of repeti- 
 tion, or even render repetition unnecessary. So we shall 
 come to perceive relations between any two things to 
 which we attend, no matter how unrelated they may at 
 first appear to be. So we shall come to believe in that to 
 which we attend in a proper, positive way, no matter how 
 absurd the thing may be on its face, nor how much it is 
 contradicted by the testimony of the senses. The absurdity 
 of the thing in which the person believes cannot be con- 
 sidered evidence of lack of mental integrity, for the wisest 
 men have advocated most absurd propositions. 
 
 Metaphysics. — These facts, that any kind of an associa- 
 tion is possible ; that any two brain centers may be 
 connected ; that the nervous impulse by repetition, 
 reasoning, or early teaching may be induced to pass from 
 any brain center into any other, is sufficient to make us 
 distrust any conclusion that is reached by a process of 
 reasoning alone. In order to justify our faith in any 
 conclusion, we must be able to check it up by facts of the 
 external world and bring it to judgment by scientific 
 means. The testimony of consciousness is always fallible 
 in consequence of the possibility of directing our nervous 
 impulse into any brain center, and arousing belief by the 
 various means suggested. Hence it is that the great 
 
86 The Thinking Process 
 
 metaphysical systems that have been promulgated from 
 time to time must always be distrusted as systems of 
 ultimate truth, unless they are verified by the means 
 proposed in the discussion of hypothetical reasoning. The 
 fact that no two great metaphysical systems are consonant 
 with each other, but are mutually exclusive, seems to 
 indicate that they will not endure the tests applied to 
 hypothetical reasoning. But that one person is unable to 
 discover any indications of sanity in the system of one 
 philosopher should not indicate to us that the philosopher 
 is lacking in sanity. He sees the relations that he thinks 
 he sees. The difficulty is that another person is unable 
 to cause an impulse to traverse the same route between 
 two brain centers. Hence it is that all metaphysical 
 systems which fail to pass the tests applied to hypotheti- 
 cal reasoning are not likely to have a very high value in 
 developing a scientific conception of the world and the 
 functions of human life in it. 
 
 Children's Reasoning.— We are sometimes asked if 
 little children reason. The question is scarcely a proper 
 one until we have clearly stated a definition of reasoning. 
 If we define reasoning as the perception of resemblances, 
 as is done in this book, then of course children reason. 
 The little three and a half year old boy who said "If this 
 (motioning with his hand) is below, then this (another 
 motion) is be up," reasoned as truly as did any philosopher. 
 So the little boy who said to his father, sweeping out an 
 aquarium "What are you brooming it out for ? " reasoned 
 very truly. He perceived resemblance between the noun 
 and the name of the action that led him to coin a new 
 word. The evidence that children do not reason is 
 generally derived from the fact that children's actions are 
 sometimes different from those that a grown-up man 
 
The Thinking Process 87 
 
 would perform in the same situation. The difficulty is 
 not that the child did not reason; but that he did not 
 inhibit his reasoning by the contradictory modifying idea. 
 He reasoned and reached his conclusion too promptly, 
 without delaying his reasoning process, c. 
 
 Unity of all Intellectual Processes.— We see that it is 
 difficult to discriminate a reasoning process from any 
 other intellectual operation. Perception and reasoning 
 are so similar that it is possible to discover the same 
 essential element in. the two, and it is difficult to draw the 
 line of separation. It is scarcely necessary nor advisable 
 to separate the intellectual process into its different 
 varieties on the basis of complexity, since the different 
 degrees shade into each other. It is a maxim in botany 
 and zoology that if two different forms of animals or 
 plants are connected by an indefinite number of inter- 
 mediate forms the two belong to the same species, and to 
 the same line of descent. Applying this principle to the 
 processes of the intellect we shall see that it is necessary 
 to discard all specific distinctions in the intellectual pro- 
 cesses. 
 
 The Ego, or Empirical Self.— The perception of resem- 
 blance is the very core of the idea of personal identity. 
 Every mental process is similar to every other mental 
 process. We should not call them all mental if they were 
 not. But the mental processes of one person are abso- 
 lutely distinct from the mental processes of another 
 person, and this constitutes the boundary line between 
 different persons, or individuals. The ego idea is obtained, 
 like any other general abstract notion, by the process of 
 generalization, from a comparison of mental experiences. 
 It is no more an intuitive idea than is any other. 
 
88 The Thinking Process 
 
 Personal Identity.— We have found the physiological 
 concomitant of the element of sameness in mental pro- 
 cesses to be transmission of a nervous impulse through 
 the same brain cells that have been traversed before. So 
 we may find the concomitant of the element of sameness 
 that belongs to all mental experiences in the transmission 
 of an impulse in the same circumstance. After a sufficient 
 number of impulses have been transmitted, a sufficient 
 number of brain cells developed and brain centers formed, 
 it becomes practically impossible for a child to have a 
 mental experience that does not involve transmissions 
 through centers, some of whose cells have been traversed 
 before in other combinations. This we may assume to be 
 the concomitant of sameness in all mental processes, and 
 the basis of continuity involved between any series of 
 mental processes and any other. 
 
 Alterations of Personality.— As the brain cells change, 
 the identity changes, and the person becomes a different 
 being from what the little child was. Alterations of per- 
 sonality are pathological interruptions of this physiologi- 
 cal continuity, and were it complete, the total personality 
 would be altered and a new person developed. 
 
 Motives to Action. — Thinking consists in the perception 
 of relations. It may or may not terminate in action. If 
 the relations perceived are those between the individual 
 and some other object, it will in all probability result in 
 action. If the relation perceived is between two terms or 
 circumstances, neither one of which is the individual, no 
 action follows. 
 
 Idea as Motive. — Many actions are performed without 
 thought. They are reflexes arising from nervous connec- 
 tions that are already organized in the individual, have 
 
The Thinking Process 89 
 
 been established by variation, fixed by natural selection, 
 and transmitted by heredity. The motive to an action is 
 the idea of the action itself, or the idea of the result of the 
 action. In order that an idea shall result in action, it must 
 be the idea of that action or of its result. If the idea is an 
 idea of some other kind, it does not constitute a motive to 
 action. When the perception of relations terminates in 
 the idea of an action, then thinking results in activity. 
 Otherwise, thinking does not necessarily do so. 
 
 Thinking and Racial Superiority.— The human race holds 
 its position at the head of animated creation in conse- 
 quence of its greater intellectual power, which is expressed 
 by saying its ability to think, or to perceive relations. 
 Man perceives relations that other animals are unable to 
 discover, and thinking determines the actions by means of 
 which man maintains himself at the head of the animal 
 kingdom. It is thinking that determines what actions will 
 be advantageous to him, and the process results in direct 
 benefit to the individual, preserving him from dangers, or 
 adjusting him better to the situation in which he finds 
 himself placed. 
 
INDEX 
 
 Abstraction 22 
 
 Abstract Notion 21, 28 
 
 Affirmative judgment 43 
 
 Analogy... 70 
 
 Analysis 22 
 
 Angell's figure for association 15 
 
 Argon.. _ 26 
 
 Association 7 
 
 centers of 17 
 
 formula for, Titchener's 14 
 
 laws of _ _ 7 
 
 simultaneous.. _ ...13 
 
 successive 13 
 
 Attention 85 
 
 Belief 84 
 
 Centrally initiated impulse.. 21 
 
 Character. 40 
 
 Children's reasoning ._ 87 
 
 Classification... ...78 
 
 Comparison ...23, 27, 30 
 
 Complete induction 65 
 
 Comprehension 38 
 
 Common noun ...21 
 
 Concrete notion _ 8 
 
 Contiguity 8 
 
 Copula 44 
 
 Crousaz... .45 
 
 Deduction ___64 
 
 Deductive reasoning 64 
 
 Definitions 19, 32, 41, 50, 61, 69, 81 
 
 Definition, logical— 35 
 
 Differences, table 26 
 
 Differentia 34 
 
 Discrimination 23, 26 
 
 Extension 38 
 
 Fallacies ...56 
 
 Faint sensations 21 
 
 Figures of the syllogism 57 
 
 Flechsig ..17 
 
 Formula for association.Titcheners.14 
 
 General abstract notion 21, 28 
 
 Generalization 40 
 
 Genius 83 
 
 Genus _ 34 
 
 summum 39 
 
 Gravitation _. ...76 
 
 Hypothesis 75 
 
 verification of 76 
 
 Humor 83 
 
 Identity 45 
 
 personal _ 86 
 
 Imagination 18 
 
 Inductive reasoning 64 
 
 Induction, complete 77 
 
 Judgment 42 
 
 affirmative 43 
 
 negative 43 
 
 particular 46 
 
 qualitative 43 
 
 relations of 48 
 
 universal _ 46 
 
 Knowledge 30 
 
 Lord Rayliegh 26 
 
 Life, defined ._ .39 
 
 Limitations of the syllogism 62 
 
 Logical definition 35 
 
 Mathematical prodigies.. 68,83 
 
 Man's superiority 88 
 
 Metaphysical systems „ 85 
 
 Mind. _ 40 
 
 Mill, John Stuart 71 
 
 Mnemonic lines. 59 
 
 Moods of the syllogism 59 
 
 Nature, uniformity of 66 
 
 Naming 81 
 
 Negative judgment. 43 
 
 Negative premises 57 
 
 New elements 27 
 
 Neptune 77 
 
 Newton 76 
 
 Notion, general abstract ..21-28 
 
 singular concrete 8 
 
 Noun, common _ 21 
 
 proper 21 
 
 Number forms 29 
 
 Peripherially initiated impulse 21 
 
 Personal identity .86 
 
 Particular judgment 47 
 
 Poetry ..83 
 
Physiological processes in associa- 
 tion 15 
 
 Predicate ...44 
 
 Premises, negative. 57 
 
 Prodigies, mathematical.. _ 83 
 
 Propositions _ 44 
 
 kinds of 48 
 
 Proper noun 21 
 
 Qualitative judgment ...43 
 
 Quotations 7, 20, 42, 51, 68, 69, 82 
 
 Rayleigh, Lord .„_ _. 26 
 
 Rank 37 
 
 Reasoning 64 
 
 deductive 64 
 
 inductive 64 
 
 children's 87 
 
 Recognition.. _ ...78 
 
 Reflexes 88 
 
 Relation 8 
 
 Relations of propositions... 48 
 
 Relation diagram 48 
 
 Resemblances, table of 27 
 
 Resimilation 16 
 
 Sensations, faint 21 
 
 vivid 21 
 
 Sameness 86 
 
 Subject ..44 
 
 Summum genus ...39 
 
 Superstitions 67, 73 
 
 Syllogism 51 
 
 figures of 57 
 
 limitations of 62 
 
 moods of 59 
 
 Table of resemblances ...27 
 
 differences ...26 
 
 Thought, train of 8 
 
 Thinking _ 82 
 
 Titchener, formula for association. .14 
 
 Undistributed term 52 
 
 Uniformity of nature... 66 
 
 Universal judgment. 26 
 
 Uranus 72, 74 
 
 Verification of hypothesis 76 
 
 Wit _ 83 
 
 QUOTATIONS 
 
 Baldwin 24,32 
 
 Binet _ 7 
 
 Bain 21 
 
 Hamilton _..20 
 
 Haeckel 57 
 
 Hoffding. 8, 62, 70, 82 
 
 Huxley ,7, 70 
 
 James 7, 62,82 
 
 Jevons 20, 42, 59, 62, 70 
 
 LeBon. ...70 
 
 Morgan, Lloyd... 62 
 
 Pillsbury ...7,40 
 
 Spencer 7, 8, 57 
 
 Thorndike ..20 
 
 Ziehen _ 7, 8, 42. 51 
 
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