Full Idea
When the subject in question is the good, beauty is a rigorous and positive proof.
Gist of Idea
Beauty is the proof of what is good
Source
Simone Weil (The Need for Roots [1943], III 'Growing')
Book Reference
Weil,Simone: 'The Need for Roots' [Routledge 2002], p.266
A Reaction
Purest platonism! It is incomprehensible to say 'this thing is evil, but it is beautiful'. But there are plenty of things which strike me as beautiful, without connecting that in any way to moral goodness.