A student of Plato who held that pleasure is the supreme Good. His arguments are as follows:
  • All creatures, rational and irrational, are attracted to pleasure.
  • What is desirable is good, so what is most desirable must be Best.
  • Since all creatures desire pleasure, that which draws all must be best for all.
  • That which is good for all must be the supreme Good.
Eudoxus felt that the best "desirable" things were those that were not chosen as a means to some other desirable thing; and that pleasure was this kind of thing. No one ever asks why a person would want to enjoy herself. So pleasure is something seeked for its own sake alone; and for this reason, to Eudoxus at least, its a noble end.

Aristotle, in Book 10 of the Nicomachean Ethics, tells us that Eudoxus was a man of excellent character and self control. So people did not believe he advocated this position because he himself was a pleasure seeker, but because "the facts really were so." (It need hardly be stated that Aristotle goes on to demolish this simple and pleasant ethic.)

What Aristotle did not bring up is this: if pleasure is the supreme good, and if Eudoxus was a man of exceptional self control (meaning, I assume, that he did not conspicuously pursue pleasure), why wasn't Eudoxus held to be a hypocrite? His contemporaries seemed to admire Eudoxus for his self denial but, given the views he was spouting, they should have reviled him on the same account.