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

I do so hate to leave this world.

Civilized life has altogether grown too tame, and, if it is to be stable, it must provide a harmless outlets for the impulses which our remote ancestors satisfied in hunting.

Why repeat the old errors, if there are so many new errors to commit?

Bolshevism is to be reckoned with Mohammedanism rather than with Christianity and Buddhism. Christianity and Buddhism are primarily personal religions, with mystical doctrines and a love of contemplation. Mohammedanism and Bolshevism are practical, social, unspiritual, concerned to win the empire of the world.

The problem with the wise is they are so filled with doubts while the dull are so certain.

In attempting to understand the elements out of which mental phenomena are compounded, it is of the greatest importance to remember that from the protozoa to man there is nowhere a very wide gap either in structure or in behaviour. From this fact it is a highly probable inference that there is also nowhere a very wide mental gap.