It is in our hearts that evil lies, and it is from our hearts that it must be plucked out.

Philosophy arises from an unusually obstinate attempt to arrive at real knowledge. What passes for knowledge in ordinary life suffers from three defects: it is cocksure, vague and self-contradictory. The first step towards philosophy consists in becoming aware of these defects, not in order to rest content with a lazy scepticism, but in order to substitute an amended kind of knowledge which shall be tentative, precise and self-consistent.

Logic must no more admit a unicorn than zoology can.

What the world needs is not dogma but an attitude of scientific inquiry.

We do not like to be robbed of an enemy; we want someone to hate when we suffer. It is so depressing to think that we suffer because we are fools; yet, taking mankind in the mass, that is the truth.

This is one of those views which are so absolutely absurd that only very learned men could possibly adopt them.

What is best in mathematics deserves not merely to be learnt as a task, but to assimilated as a part of daily thought, and brought again and again before the mind with ever-renewed encouragement.