Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and unbearable pity for the suffering of mankind.

Modern life cannot be constructed on . . . physically strenuous principles. A great deal of work is sedentary, and most manual work exercises only a few specialized muscles.

The governors of the world believe, and have always believed, that virtue can only be taught by teaching falsehood, and that any man who knew the truth would be wicked. I disbelieve this, absolutely and entirely. I believe that love of truth is the basis of all real virtue, and that virtues based upon lies can only do harm.

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.

I do not pretend to start with precise questions. I do not think you can start with anything precise. You have to achieve such precision as you can, as you go along.

Curious learning not only makes unpleasant things less unpleasant but also makes pleasant things more pleasant.

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.