I think it would be just to say the most essential characteristic of mind is memory, using this word in its broadest sense to include every influence of past experience on present reactions.

One of the most interesting and harmful delusions to which men and nations can be subjected is that of imagining themselves special instruments of the Divine Will.

Beggars do not envy millionaires, though of course they will envy other beggars who are more successful.

To create a healthy philosophy you should renounce metaphysics but be a good mathematician.

The experience of overcoming fear is extraordinarily delightful.

To modern educated people, it seems obvious that matters of fact are to be ascertained by observation, not by consulting ancient authorities. But this is an entirely modern conception, which hardly existed before the seventeenth century.

A hallucination is a fact, not an error; what is erroneous is a judgment based upon it.