Note 1 — Chapter XIX · THE MORAL SCIENCE OF THE EPICUREANS. GENERAL PRINCIPLES.

The only unconditional good, according to Epicurus, is pleasure; the only unconditional evil is pain.1 No proof of this proposition seemed to him to be necessary; it rests on a conviction supplied by nature herself, and is the ground and basis of all our doing and not doing.2 If proof, however, were required, he appealed to the fact that all living beings from the first moment of their existence pursue pleasure and avoid pain,3 and that consequently pleasure is a natural good, and the normal condition of every being.4 Hence follows the proposition to which Epicurus in common with all the philosophers of pleasure appealed, that pleasure must be the object of life.