Full Idea
Philosophical knowledge does not differ essentially from scientific knowledge; there is no special source of wisdom which is open to philosophy but not to science.
Gist of Idea
Philosophy is similar to science, and has no special source of wisdom
Source
Bertrand Russell (Problems of Philosophy [1912], Ch.14)
Book Reference
Russell,Bertrand: 'The Problems of Philosophy' [OUP 1995], p.87
A Reaction
I agree. I take Plato's Theory of Forms, for example, to be a scientific theory, for which no one can devise an empirical test (just like string theory). Personally I consider philosophy to be the senior partner, and regard scientists as servants.