Full Idea
Just as there is no benefit to medicine if it does not heal the sicknesses [nosos] of bodies, so too there is none to philosophy unless it expels that affections of the soul.
Gist of Idea
The aim of medicine is removal of sickness, and philosophy similarly removes our affections
Source
Epicurus (fragments/reports [c.289 BCE], fr 221), quoted by James Allen - Soul's Virtue and the Health of the Body p.78
Book Reference
Adamson,Peter: 'Health: a history', ed/tr. Adamson,Peter [OUP 2019], p.78
A Reaction
This sounds rather Buddhist, if the only route to happiness is to suppress the emotions. Epicurus probably refers to the more extreme desires, which only lead to harm. Galen quotes Chrysippus as endorsing this idea (see footnote 5).