Full Idea
A just blend of unity and that which opposes it is the condition of the beautiful, and it is the secret of art.
Gist of Idea
The secret of art is that beauty is a just blend of unity and its opposite
Source
Simone Weil (The Scientific Image [1941], p.169)
Book Reference
Weil,Simone: 'Late Philosophical Writings' [Notre Dame 2015], p.169
A Reaction
Rather sweeping, but the observation strikes me as fairly accurate. It seems to work for most novels, paintings and music, though more recent art may provide counterexamples.