Abstract

In the Republic Plato contrasts dialectic with mathematics on the grounds that the former but not the latter gives justifications of some kind for its hypotheses, pursuing this process until it reaches ‘an unhypothetical principle’. But which principles are unhypothetical, and why, is rather dark. One reason for this is the scarcity of forms of that precious word, ‘unhypothetical’ (aνυπoθετος), used only twice by Plato (Rep. 510 b 7, 511 b 6) and just once by Aristotle (Metaph. 1005B14). But that very scarcity also suggests the intriguing possibility that Aristotle has Plato’s text in mind when he uses the word, so we might expect to understand Plato better by grasping how Aristotle took him. That is a notoriously defeasible assumption since plenty of modern accounts of Plato want to save him from Aristotle’s numerous critiques, and hence imply that the master of them that know frequently missed the point when it came to his own master. But surely we can be more confident that Aristotle will give us access to Plato when it appears not merely that he is dealing with the same topic, but using the same rare vocabulary to boot. Hence the understandable temptation to turn to Metaphysics Γ for help in identifying Platonic unhypothetical principles. I shall argue that Aristotle is indeed thinking of Plato’s text when he uses the word for ‘unhypothetical’, and further that what is explicitly an unhypothetical principle for Aristotle might well have been one for Plato too. But later I shall claim that their joint use of a much more common word in the same philosophical context is either coincidence or misunderstanding on Aristotle’s part, for he must mean something different by it from what Plato means.