Computatio Universalis SEU Logica Rerum. BEING An Essay attempting in a Geometrical Method, to Demonstrate an Universal Standard, whereby one may judge of the true Value of every thing in the World, relatively to the Person. LONDON, Printed and Sold by J. Moxon at the Atlas in Warwick-Lane, 1697. TO THE Royal Society. Gentlemen, I Have made a trial how some few thoughts, relating to the common concerns of the World, would look in a Geometrical Dress, and take the boldness to present them to your Honourable Society. I know your readiness to Encourage all endeavours after useful Knowledge, and therefore presume you will show some little favour to this attempt of mine, it may be, so far as to recommend it as a hint to others of a more happy Genius, to prosecute this Argument, or also a nobler Subject upon such sort of Principles as these, I have no excuse to make for the meanness of my performance, but that I know not that this was ever aimed at by any Man till now, by Your most Humble Servant. DEFINITIONS. 1 Def. BY time or the Age of a Man, I desire may be understood all that part of a Man's Life, which he can employ as he himself judges convenient, and therefore, after he is come to the use of Reason. 2 Def. By a Man's Estate, I understand all the Wealth and Riches, which in the time of his Reason he is Master of, and has at his own disposal; whether it be by the kindness of his Relations, or the Fruits of his own Industry. 3 Def. By Happiness, I understand all the Ease, and Satisfaction, and Pleasures which a Man can procure by his Estate, and which do not come upon him without his own choice and forecast. 4 Def. By Wisdom, I understand a Sk●● and Resolution to procure all the Happiness which is procurable by such a Man. 5 Def. By a Fool, I understand one wh● either does not know how, or does not resolve to procure all the Happiness which i● procurable by him. 6 Def. By Pleasures, I mean all sorts of innocent Diversions, Conversation, Balls, Plays, Drinking, Gaming, Hunting, Hawking, and the like; according to men's different Fancies and Inclinations. POSTULATA. 1 Post. THat in order to the making a better Comparison between things, it may be allowed us to fix upon some determinate number of Years, and to call that the apparent Age or Time of a Man. 2 Post. That upon the same Account, it may be allowed us to fix upon a determinate sum of Money, and to call that, the apparent Estate of a Man. 3 Post. That it may be allowed us to subduct from the apparent Time, and from the apparent Estate of a Man, all those parts of his Age and Wealth which are not at his own disposal. 4 Post. That the value of time may be expressed by a proportionable value in Money. 5 Post. That it may be allowed us to assign different pleasures and satisfactions to the different Stages and Periods of a Man's life, and till a truer and more particular and exact one be offered, to make use of this following Scheme. All School-learning, Grammar, Arithmetic, Writing, etc. 1 Part from 9 to 16 All sorts of Academical Learning, Travels, and Pleasures, and Exercises suitable to that period. 2 P. from 16 to 25 Recreations, Courtships and Pleasures suitable. 3 P. from 25 to 36 Honours, Preferments and Pleasures suitable. 4 P. from 36 to 49 Increasing of Riches, Power and Interest, and pleasures suitable. 5 P. from 49 to 64 AXIOMS. 1 Ax. Time is as necessary to enjoy Happiness in, as an Estate is necessary to procure it. 2 Ax. The same proportion that the whole Happiness of a Man's Life bears to his whole Time and Estate, the same proportion do the distinct parts of his Happiness bear to proportionable parts of his Time and Estate. 3 Ax. Happiness is worth as much Time, and as much Money, as are absolutely necessary to procure and to enjoy it. Proposition 1. If a Man do live from his Birth to the end of 64 Years, that is, has 64 apparent years, his real time or true age is but 32 years. Demonstration. Such a Man's time (by the 1st Definition) is only that part of his Life which he can employ as he himself judges most convenient after he is come to the use of Reason, and therefore (by the 3d Postulat.) I make these following subductions. Y. M. D. H. He is to live. 64 00 00 00 Subducted out of it, viz. 1 For Childhood, before he gins to use his Reason to any purpose. 64 00 00 00 2. For Sleep, at the rate of 8 hours in 24, because he cannot employ it at he pleases in the purchase and enjoyments of satisfaction. 09 00 00 00 3. For Devotion, reckoning that as God's time. 18 04 00 00 4. For Sickness, such as disables him from taking satisfaction in the things of the World at least. 03 06 00 00 The whole sum of the Deductions. 01 02 00 00 The Remainder therefore which is the Man's time, is 32 00 0 0 Which was to be Demonstrated. 32 00 0 0 Pro. 2. If such a Man has an Estate of Inheritance of 120 l. per Ann. his whole real Estate is 4940 l. Sterling. Demonstra. By the 2d Definition, his true Estate is only so much of his Wealth, as in the time of his reason he has at his own disposal, and therefore (by the 3d Postulat.) I make the following subductions. The whole sum arising from 120 l. per Ann. during the 64 years, without interest or any other improvements amounts to. l. s. d. Subducted out of it, viz. 7680 00 00 1. For the 9 years of Childhood. 1080 00 00 2. For Charity being God's and the poors Money, and public Taxes being the Magistrates and his Country's Money 1/100 660 00 00 3. For unavoidable expenses in Sickness. 0100 00 00 4. For Food and Lodging just necessary. 0480 00 00 5. For . 0420 00 00 The whole sum of the Deductions ●740 00 00 Taken out of ●680 00 00 The Remainder is. 4940 00 00 Which is his real Estate Which was to be Demonstrated. Prop. 3. The whole Happiness of such a Man's Life is worth 32 Years and 4940 l. Demonstra. By the 3d Definition, the whole Happiness of Man's Life is all the Ease, and Pleasure, and Satisfactions which he can procure by his Estate, during the whole time of his life. But by the 1st Proposi. the time of such a Man's life is 32 Years, and by the 2d Prop. his Estate is 4940 l. and by the 3d Axiom, Happiness is worth as much time, and as much Money as are absolutely necessary to procure and to enjoin it; therefore the whole Happiness of such a Man's Life is worth 32 Years and 4940 l. Which was to be Demonstrated. Prop. 4. Such a Man is wise if he does know how, and resolves to procure as much happiness as is worth 32 Years and 4940 l. Demonstra. By the 4th Definition, Wisdom is a Skill and Resolution to procure all the Happiness which a Man can procure. But by the 3d Prop. all the Happiness of such a Man's life is worth 32 Years and 4940 l. therefore such a Man is wise if he knows how and resolves to procure as much Happiness as is worth 32 Years and 4940 l. Which was to be Demonstrated. Prop. 5. Such a Man is a Fool, if he does not know and resolve to procure as much Happiness as is worth 32 Years and 4940 l. Demonstra. By the 5th Definition, that Man is a Fool who does not know and resolve to procure all the Happiness which is procurable by him; but by the 3d Prop. all the Happiness procurable by such a Man is worth 32 Years and 4940 l. therefore such a Man is a Fool, if he does not know and resolve to procure as much Happiness as is worth 32 Years and 4940 l. Which was to be Demonstrated. Corollary. Hence it follows that such a Man is a Fool, if he lays out upon any particular and determinate part of the Happiness of his whole life, more of his 32 Years and 4940, than that part of his Happiness has proportion to his whole Happiness; for, by the 2d Axiom, the same proportion that the whole Happiness of Man's life does bear to his whole Time and Estate, the same proportion do the distinct parts of his Happiness bear to proportionable parts of his Time and Estate. Since therefore he is a Fool if he does not know and resolve to procure as much Happiness as is worth 32 Years and 4940 l. he must be a Fool if he gives more of his 32 Years and 4940 l. for any part of Happiness, than that proportion which that part of Happiness bears to the Happiness of his whole life; Ergo, he is a Fool that lives fast. (Quod saepious probatum est) which two faults we usually term, living fast, and Prodigality. Prop. 6. Such a Man is more wise as he comes nearer the procuring as much Happiness as is worth 32 Years and 4940 l. and the more a Fool as he comes shorter of procuring of it. Demonstra. This follows clearly from the 4th and 5th Propositions. Problem. 1. How to express the value of such a Man's time in Money. By the 4th Postulation, The value of Time may be expressed by a proportionable value in Money; therefore since by the 1st Prop. the whole time of such a Man is 32 Years, and by the 2d Prop. his whole Estate is 4940 l. it will follow that. l. s. d. q. 1. One of his Years is worth Sterl. 154 07 06 00 2. One Month. 12 17 03 01 3. One Day. 00 08 05 01 4. One Hour about. 00 00 04 0¼ 5. One Minute. 00 00 00 3/10 of ¼ A Table showing what common Money does amount to of such a Man's Money. viz. 7680 l. 4940 l. 1 l. come. such a Man's M. Money. lib. l. s. d. q 1 00 12 10 1 2 01 05 08 3 3 01 18 07 0 4 02 11 05 2 5 03 04 03 3 6 03 17 02 1 7 04 10 00 2 8 05 02 11 0 9 05 15 09 1 10 06 08 07 3 20 12 17 03 2 30 19 05 11 1 40 25 14 07 0 50 32 03 02 3 60 38 11 10 2 70 45 00 06 1 80 51 09 02 0 90 57 17 09 3 100 64 06 05 2 200 128 12 11 0 300 192 19 04 2 400 257 05 10 0 500 321 12 03 2 600 385 18 09 0 700 450 05 02 2 800 514 11 08 0 900 578 18 01 2 1000 643 04 07 0 1000 643 04 07 0 The Table is made according to this Proportion. As the whole time between the beginning of the 2d Period, and the end of his Life, viz. 55 Years is to his Time, viz. 32 Years; so is one Year to 212 days of his real time, and the value 89 l. 16 s. etc. Lemma. That in the following Propositions, allowances must be made for the different Inclinations and fancies of Men and expectations in the World. But what is laid down determinately, may now pass for a good general mean. Prop. 7. Such a Man is a Fool, if he lay out upon what Happiness may be included within the first period above 4 years and 26 days 13 hours of his time, and 628 l. 16 s. 6 d. of his Money. Demonstra. By the Coral. from the 5th Prop. such a Man is a fool if he lays out upon any particular and determinate part of the Happiness of his whole life, more of his 32 years and 4940 l. than that part of his Happiness has proportion to his whole Happiness. But by the Scheme in the 5th Postula. it appears, that the Happiness of the first period is answerable to 7 common years, and this amounts to 4 years and 26 days 13 hours of his time, and 628 l. 16 s. 6 d. of his Money; there fore such a Man is a fool if he lay out upon the 1st period, above 4 years and 26 days and 12 hours of his time, and above 628 l. 17 s. 6 s. of his Money. Which was to be Demonst. Prop. 8. Such a Man is a fool if he lays out upon the Happiness of the 2d period above 5 years and 86 days 7 hours of his time, and 808 l. 09 s. 9 d. of his Money. The Demonstration is the same as of the 7th Prop. Prop. 9 Or if he lays out upon the Happiness of the 3d period, above 6 Years and 146 days 8 hours of his time, and above 988 l. 03 s. 01 d. ¼ of his Money. The Demonstration is the same as that of the 7th Prop. Prop. 10. Or if he lays our upon Honours, Preferments and Pleasures, suitable to the 4th period above 7 years and 206 days 2 hours of his time, and above 1167 l. 16 s. 4 d. ¾ of his Money. The same way Demonstrated. Prop. 11. Or if upon the Happiness of the 5th and last period above 8 years and 265 days 21 hours of his time, and above 1347 l. 09 s. 8 d. ¼ of his Money. The same Demonstration Problem 2. How to express the real value of an acquired Estate. If such a Man by that time he is 30 years of Age, having discharged all former Debts and Encumbrances, has by his labour acquired just 120 l. per Ann. and is to live to 64, his Estate is 2245 l. 08 s. 0 d. For 120 l. per Ann. the other 34 Years amounts to. l. s. d. Out of which (as Prop. 2.) must be subducted. 4080 00 00 1. For Charity. 408 00 00 2. For Sickness about. 172 00 00 3. Food and Lodging. 292 00 00 4. For . 252 00 00 5. For the value of his time between the 9th and 30th Year of his Age, supposing that by the labour, to acquire that Estate 6 Hours every day came to be not at his own disposal, by the 1st Problem about. 810 12 00 The sum of which Deduction. 1834 12 00 Taken out of. 4080 00 00 The Remainder. 2245 08 00 Hence appears the true difference between an acquired Estate, and an Estate of Inheritance, the time spent in acquiring it, being converted into Money, in the above case being. 810 12 00 Problem 3. To apply the foregoing Propositions to particular uses, and for instance, by this method to find out the real value of an Horse. We proceed by these Degrees. 1. We set down the Man's Age who is to buy it, suppose 33. 2. The Period which it falls in here 'tis the 3d. 3. The remainder of the Money which the Man has to spend in the remainder of the period, which is thus found. By the 5th Postulation, the common years of the 3d Period are 11, and by the 9th Prop. the Money to be spent in those 11 Years is 988; therefore since 8 years of the 11 are now supposed to be passed, valued at 718 l. 6/11 not troubling ourselves with the Fractions; we subduuct the Money already spent, viz. the 718 l. out of 988 l. the whole, and the remainder will be 270 l. which is the sum that is at his disposal in those 3 years. 4. Suppose an indifferent Horse, and the Market Rate to be 10 l. 5. Suppose him (bating Accidents) to be serviceable 10 Years. 6. Suppose the yearly charge of keeping him to be at least 5 l. and so the Money to be laid out upon him will be 60. 7. That the Pleasure, Profit, or Service which that Horse must do such a Man, that he may be no loser by him, must be worth of such a Man's Money 60 l. in 10 years, (that is 6 l. per Ann.) and so for the 3 years of the period which the Man is then in, he must be worth 18 l. of his Money (for 10 y. 60 l. 3 y. 18 l.) and in the period he must be worth 42 l. being the remainder, and therefore. 8. The Man must consider what occasion he has for 270 l. in those 3 years, and whether he can wisely allow 18 l. being 1/15 of the value of the Happiness of the 3 years for it; and whether he may allow it or no, he may find by the Corollary of the 5th Proposition. If he finds that he must not allow so much, then by making subductions for what remains to be subducted, after taking out 14/15 from 270 l. the remainder will be the exact sum which he may afford for the Horse, and that will be to him the real value of it. That is to say, If he finds, for instance, that besides 252 l. which is 14/15 of 270 l. he shall have occasion to lay out 10 l. upon other things; let him subduct the 262 l. from 270 l. and the remainder being 8 l. will be the real value of the Horse, after the same manner the value of a Servant, Book, Garment, Watch, etc. may be found out. Est aliquid prodire tenus. FINIS. Note, That Erratas in the Calculation, may be easily mended by the Reader in observing the inferences of the Reasonings.