Aristotle, Nicomachean Ethics
H. Rackham, Ed.

To apply the term ‘compulsory’ to acts done for the sake of pleasure or for noble objects, on the plea that these exercise constraint on us from without, is to make every action compulsory. For （1） pleasure and nobility between them supply the motives of all actions whatsoever. Also （2） to act under compulsion and involuntarily is painful, but actions aiming at something pleasant or noble are done with pleasure. And （3） it is absurd to blame external things, instead of blaming ourselves for falling an easy prey to their attractions; or to take the credit of our noble deeds to ourselves, while putting the blame for our disgraceful ones upon the temptations of pleasure.