Full Idea
It is not possible to live pleasantly without living intelligently and finely and justly, nor to live intelligently and finely and justly without living pleasantly.
Gist of Idea
Pleasure and virtue entail one another
Source
Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 5), quoted by Julia Annas - The Morality of Happiness Ch.16
Book Reference
Annas,Julia: 'The Morality of Happiness' [OUP 1995], p.340