SECT. XLIV. Matter Cannot Think.

Knows.

But the body of man, which appears to be the masterpiece of nature, is not to be compared to his thought. It is certain that there are bodies that do not think: man, for instance, ascribes no knowledge to stone, wood, or metals, which undoubtedly are bodies. Nay, it is so natural to believe that matter cannot think, that all unprejudiced men cannot forbear laughing when they hear any one assert that beasts are but mere machines; because they cannot conceive that mere machines can have such knowledge as they pretend to perceive in beasts. They think it to be like children's playing, and talking to their puppets, the ascribing any knowledge to mere machines. Hence it is that the ancients themselves, who knew no real substance but the body, pretended, however, that the soul of a man was a fifth element, or a sort of quintessence without name, unknown here below, indivisible, immutable, and altogether celestial and divine, because they could not conceive that the terrestrial matter of the four elements could think, and know itself: Aristoteles quintam quandam naturam censet esse, è quâ sit mens. Cogitare enim, et providere, et discere, et docere. . . . in horum quatuor generum nullo inesse putat; quintum genus adhibet vacans nomine.

But let us suppose whatever you please, for I will not enter the lists with any sect of philosophers: here is an alternative which no philosopher can avoid. Either matter can become a thinking substance, without adding anything to it, or matter cannot think at all, and so what thinks in us is a substance distinct from matter, and which is united to it. If matter can acquire the faculty of thinking without adding anything to it, it must, at least, be owned that all matter does not think, and that even some matter that now thinks did not think fifty years ago; as, for instance, the matter of which the body of a young man is made up did not think ten years before he was born. It must then be concluded that matter can acquire the faculty of thinking by a certain configuration, ranging, and motion of its parts. Let us, for instance, suppose the matter of a stone, or of a heap of sand. It is agreed this part of matter has no manner of thought; and therefore to make it begin to think, all its parts must be configurated, ranged, and moved a certain way and to a certain degree. Now, who is it that knew how to find, with so much niceness, that proportion, order, and motion that way, and to such a degree, above and below which matter would never think? Who is it that has given all those just, exact, and precise modifications to a vile and shapeless matter, in order to form the body of a child, and to render it rational by degrees? If, on the contrary, it be affirmed that matter cannot become a thinking substance without adding something to it, and that another being must be united to it, I ask, what will that other thinking being be, whilst the matter, to which it is united, only moves? Therefore, here are two natures or substances very unlike and distinct. We know one by figures and local motions only; as we do the other by perceptions and reasonings. The one does not imply, or create the idea of the other, for their respective ideas have nothing in common.