The debate over the value of pleasure among Eudoxus, Speusippus, and Aristotle is dramatically documented by the Nicomachean Ethics, particularly in the dialectical pros-and-cons concerning the so-called argument from contraries. Two similar versions of this argument are preserved at EN VII. 13, 1153b1–4, and X. 2, 1172b18–20. Many scholars believe that the argument at EN VII is either a report or an appropriation of the Eudoxean argument in EN X. This essay aims to revise this received view. It will explain (...) why these two arguments differ in premises, contents and purposes, and why these distinctions matter for a proper assessment of Aristotle’s understanding of pleasure and pain in general and his dialectical art in particular. (shrink)