In this bold and engaging book, Christiana Olfert defends a novel account of the notion of “practical truth” and explains its significance for Aristotle's ethics and philosophy of action. That practical truth should play a central role in Aristotle's argument in the Nicomachean Ethics may seem surprising: “alêtheia praktikê” appears exactly once in Aristotle's corpus, at Nic. Eth. VI 2, 1139a26–27,1 and is not usually counted among Aristotle's significant conceptual innovations.
Olfert argues that the notion of practical truth in fact underpins one of Aristotle's most famous distinctions: between theoretical and practical reason. If her analysis is correct, this division presupposes the existence of a particular kind of truth—practical truth—that differs in species from theoretical truth: because there is practical truth, there is practical reason. While both types of truth according to Olfert are propositional, and therefore truths in the “perfectly ordinary” sense that Aristotle describes at...
