Aristotle’s Philosophy of Nature and Theory of Potentiality

Abstract

The possible (δυνατóν) is, obviously a close relative of potentiality (δύναμις), but how close are they, exactly? And, to start with, when is something possible? If we define it, as we tend to, as that which does not involve any contradiction or impossibility were it to actualise, it would follow that almost anything is possible. If this is a view too wild to hold, its presupposition must be rejected, and this presupposition is that what is thus possible may not actualise. For by rejecting this seemingly innocent assumption, the range of the genuine possibles is at once drastically reduced to just those which actualise, and thus not everything can be said to be genuinely possible. This is how Aristotle conceived the alternatives:

If, as we said, that [alone, Z.B.] is possible which does not involve impossibility, it cannot be true to say that a thing is possible but will never be, for it would imply that there is nothing incapable of being [anything else. Z.B].

(Met. 1047b3) So, the two assumptions (a) the possible is that which does not involve impossibility, (b) some things are impossible, entail the consequence that (c) the possible must actualise. Aristotle’s implied proof of this entailment is that the conjunction of (a) and the negation of (c) entails the negation of (b), which is an absurdity. Hence the negation of (c) is inconsistent with the conjunction of (a) and (b).