id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
en-wikipedia-org-9424		Unobservable - Wikipedia			.html	text/html	1266	207	53	An unobservable (also called impalpable) is an entity whose existence, nature, properties, qualities or relations are not directly observable by humans. In philosophy of science, typical examples of "unobservables" are the force of gravity, causation and beliefs or desires.[1]:7[2] The distinction between observable and unobservable plays a central role in Immanuel Kant's distinction between noumena and phenomena as well as in John Locke's distinction between primary and secondary qualities. The ontological nature and epistemological issues concerning unobservables are central topics in philosophy of science. It contrasts with instrumentalism, which asserts that we should withhold ontological commitments to unobservables even though it is useful for scientific theories to refer to them. It contrasts with instrumentalism, which asserts that we should withhold ontological commitments to unobservables even though it is useful for scientific theories to refer to them. The third kind is the physically unobservable, that which can never be observed by any existing sense-faculties of man.	./cache/en-wikipedia-org-9424.html	./txt/en-wikipedia-org-9424.txt