Full Idea
Logic has become more mathematical, and mathematics has become more logical. The consequence is that it has now become wholly impossible to draw a line between the two; in fact, the two are one.
Gist of Idea
In modern times, logic has become mathematical, and mathematics has become logical
Source
Bertrand Russell (Introduction to Mathematical Philosophy [1919], XVIII)
Book Reference
Russell,Bertrand: 'Introduction to Mathematical Philosophy' [George Allen and Unwin 1975], p.194
A Reaction
This appears to be true even if you reject logicism about mathematics. Logicism is sometimes rejected because it always ends up with a sneaky ontological commitment, but maybe mathematics shares exactly the same commitment.