Laughter is the corrective force which prevents us from becoming cranks.

Religion is to mysticism what popularization is to science

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

It is of man's essence to create materially and morally, to fabricate things and to fabricate himself. Homo faber is the definition I propose ... Homo faber, Homo sapiens, I pay my respects to both, for they tend to merge.

To perceive means to immobilize. To say this is to say that we seize, in the act of perception, something which outruns perception itself.

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.

To drive out the darkness, bring in the light.