Full Idea
Stoics say that pleasure is, if anything, a byproduct which supervenes when nature itself, on its own, seeks out and acquires what is suitable to the animal's constitution.
Gist of Idea
Stoics say pleasure is at most a byproduct of finding what is suitable for us
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.86
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.113
A Reaction
It would be nice if pleasure were just an indicator that you are successfully living according to nature. Human refinement of alcohol and opium have rather undermined that view (but note 'on its own'). Note also the parenthetical 'if anything'.