Aristotle maintains that every man has, or should have, a single end (τέλς), a target at which he aims. The doctrine is stated in NE I 2. ‘If, then, there is some end of the things we do which we desire for its own sake (everything else being desired for the sake of this), and if we do not choose everything for the sake of something else (for at that rate the process would go on to infinity, so that our desire would be empty and vain), clearly this must be the good and the chief good. Will not the knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what is right?’1 (1094a 18–24). Aristotle does not here prove, nor need we understand him as claiming to prove, that there is only one end which is desired for itself. He points out correctly that, if there are objects which are desired but not desired for themselves, there must be some object which is desired for itself. The passage further suggests that, if there were one such object and one only, this fact would be important and helpful for the conduct of life.