The major task of the twentieth century will be to explore the unconscious, to investigate the subsoil of the mind.

It seems that laughter needs an echo.

Homo sapiens, the only creature endowed with reason, is also the only creature to pin its existence on things unreasonable.

The present contains nothing more than the past, and what is found in the effect was already in the cause.

The only cure for vanity is laughter. And the only fault that's laughable is vanity.

The major task of the twentieth century will be to explore the unconscious, to investigate the subsoil of the mind.

It is the very essence of intelligence to coordinate means with a view to a remote end, and to undertake what it does not feel absolutely sure of carrying out.