Philosophy and the Mirror of Nature: Thirtieth-Anniversary Edition (Princeton Classics)

by Richard Rorty

For Aristotle, and still for St. Thomas, the paradigm of a substance was an individual man or frog. Detached parts of men or frogs were, like clumps of turf or pailsful of water, dubious borderline cases—they were “capable of existing separately” in one sense (spatial separation), but they did not have the functional unity or “nature” which proper substances should have. Aristotle, when worried about such cases, was wont to dismiss them as “mere potencies”—as neither accidents, like the frog’s color, nor proper actualities, like the living, leaping frog itself.36 Descartes pretends that he is using “distinct substance” in the standard sense of “capable of separate existence,” but he does not mean either spatial separation or functional unity.37 He means something like “capable of having everything else disappear [or be “thought away”] and still being around.”38 This definition of “capacity for separate existence” fits the One, the Platonic Ideas, and Aristotle’s Unmoved Movers, but almost nothing else. Given such a definition, it is hardly surprising that there should turn out to be, at most, only three substances—God, mind, and matter. Nor is it surprising that Malebranche and Berkeley should begin to have doubts about the third candidate, and Spinoza about both third and second. It would not have occurred to Aristotle to think that frogs, stars, and men were simply so many accidents of one big substance merely on the ground that if we imagine all the other bodies in the ...

09-02-2020. 65.