Imagination is a poor substitute for experience.

We cannot remain consistent with the world save by growing inconsistent with our past selves.

...aesthetic values are changed under the influence of sexual emotion; from the lover's point of view many things are beautiful which are unbeautiful from the point of view of him who is not a lover, and the greater the degree to which the lover is swayed by his passion the greater the extent to which his normal aesthetic standard is liable to be modified.

When love is suppressed hate takes its place.

For every fresh stage in our lives we need a fresh education, and there is no stage for which so little educational preparation is made as that which follows the reproductive period.

Einstein is notmerely an artist in his moments of leisure and play, as a great statesman may play golf or a great soldier grow orchids. He retains the same attitude in the whole of his work. He traces science to its roots in emotion, which is exactly where art is also rooted.

The mathematician has reached the highest rung on the ladder of human thought.