It seems probable to me that God in the beginning formed matter in solid, massy, hard, impenetrable, moveable particles of such sizes and figures and with such other properties, and in such proportion to space, as most conduced to the end for which he formed them; and that these primitive particles, being solids, are incomparably harder than any porous bodies compounded of them—even so very hard as never to wear or break in pieces, no ordinary power being able to divide what God himself made one in the first creation. While the particles continue entire, they may compose bodies of one and the same nature and texture in all ages. These principles I consider not as occult qualities, supposed to result from the specific forms of things, but as general laws of nature, by which the things themselves are formed; their truth appearing to us by phenomena, though their causes be not yet discovered. For these are manifest qualities, and their causes only are occult. And the Aristotelians gave the name of occult qualities not to manifest qualities but to such qualities only as they supposed to lie hid in bodies and to be the unknown causes of manifest effects—such as would be the causes of gravity, of magnetic and electric attractions, and of fermentations—if we should suppose that these forces or actions arose from qualities unknown to us and incapable of being discovered and made manifest. To tell us that every species of things is endowed with an occult specific quality by which it acts and produces manifest effects is to tell us nothing, but to derive two or three general principles of motion from phenomena and afterward to tell us how the properties and actions of all corporeal things follow from those manifest principles would be a very great step in philosophy, though the causes of those principles were not yet discovered.
Image: Newton, by William Blake, 1795.