Knowledge is always accompanied with accessories of emotion and purpose.

The paradox is now fully established that the utmost abstractions are the true weapons with which to control our thought of concrete fact.

A philosopher of imposing stature doesn't think in a vacuum. Even his most abstract ideas are, to some extent, conditioned by what is or is not known in the time when he lives.

The guiding motto in the life of every natural philosopher should be, seek simplicity and distrust it.

The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.

Algebra reverses the relative importance of the factors in ordinary language.

The purpose of education is not to fill a vessel but to kindle a flame.