Full Idea
How could there be no evil in the world? The world has to be foreign to our desires. If this were so without it containing evil, our desires would be entirely bad. That must not happen. God's world is not the best possible, but contains all good and evil.
Gist of Idea
If the world lacked evil, then the evil would be in our desires, which would be worse
Source
Simone Weil (Gravity and Grace [1942], 'Evil')
Book Reference
Weil,Simone: 'Gravity and Grace', ed/tr. Crawford/De Ruhr [Routledge 1952], p.78
A Reaction
What an original mind she had! Doesn't seem to answer the standard problem, of why a benevolent God gave us evil desires.