Full Idea
Those who define good as pleasure are clearly confused, and are compelled to admit that there are bad pleasures, so that the same thing is both good and bad.
Gist of Idea
Even people who think pleasure is the good admit that there are bad pleasures
Source
Plato (The Republic [c.371 BCE], 505c)
Book Reference
Plato: 'Republic', ed/tr. Waterfield,Robin [OUP 1993], p.231
A Reaction
The issue is whether the pleasure can be disentangled from the action. 'It was a hideous murder, but at least the murderer enjoyed it'. Sounds wrong to me.