In reality, the past is preserved by itself automatically.

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

There are manifold tones of mental life, or, in other words, our psychic life may be lived at different heights, now nearer to action, now further removed from it, according to the degree of our attention to life.

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

Instinct perfected is a faculty of using and even constructing organized instruments; intelligence perfected is the faculty of making and using unorganized instruments.

It seems that laughter needs an echo.

Life does not proceed by the association and addition of elements, but by dissociation and division.