Full Idea
Unfortunately, Russell's new logic, as well as preventing the deduction of paradoxes, also prevented the deduction of mathematics, so he supplemented it with additional axioms, of Infinity, of Choice, and of Reducibility.
Gist of Idea
Russell's improvements blocked mathematics as well as paradoxes, and needed further axioms
Source
report of Bertrand Russell (Mathematical logic and theory of types [1908]) by Alan Musgrave - Logicism Revisited §2
Book Reference
-: 'British Soc for the Philosophy of Science' [-], p.102
A Reaction
The first axiom seems to be an empirical hypothesis, and the second has turned out to be independent of logic and set theory.