Our laughter is always the laughter of a group.

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.

Sex-appeal is the keynote of our whole civilization.

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

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

In laughter we always find an unavowed intention to humiliate and consequently to correct our neighbour.

In short, intelligence, considered in what seems to be its original feature, is the faculty of manufacturing artificial objects, especially tools to make tools, and of indefinitely varying the manufacture.