Only in thought is man a God; in action and desire we are the slaves of circumstance.

Next to worry probably one of the most potent causes of unhappiness is envy.

Right discipline consists, not in external compulsion, but in the habits of mind which lead spontaneously to desirable rather than undesirable activities.

Philosophy, from the earliest times, has made greater claims, and achieved fewer results, than any other branch of learning.

Calculus required continuity, and continuity was supposed to require the infinitely little; but nobody could discover what the infinitely little might be.

Some people would rather die than think.

Unfortunately, however, power is sweet, and the man who in the beginning seeks power merely in order to have scope for his benevolence is likely, before long, to love the power for its own sake.