Full Idea
Chance is not the contrary of necessity; it is not incompatible with necessity. On the contrary, it never appears except at the same time as necessity.
Gist of Idea
Chance is compatible with necessity, and the two occur together
Source
Simone Weil (The Scientific Image [1941], p.175)
Book Reference
Weil,Simone: 'Late Philosophical Writings' [Notre Dame 2015], p.175
A Reaction
She illustrates it with the six terminating results of a die throw, and the innumerabe ways the throw can occur. This thought strikes me as relevant to discussions of free will. …But I'm not sure I fully understand it.