Sadness does not inhere in things; it does not reach us from the world and through mere contemplation of the world. It is a product of our own thought. We create it out of whole cloth.

There is no society known where a more or less developed criminality is not found under different forms. No people exists whose morality is not daily infringed upon. We must therefore call crime necessary and declare that it cannot be non-existent, that the fundamental conditions of social organization, as they are understood, logically imply it.

It is science, and not religion, which has taught men that things are complex and difficult to understand.

This solidarity can grow only in inverse ratio to personality... Solidarity which comes from likenesses is at its maximum when the collective conscience completely envelops our whole conscience and coincides in all points with it... when this solidarity exercises its force, our personality vanishes, as our definition permits us to say, for we are no longer ourselves, but the collective life.

The roles of art, morality, religion, political faith, science itself are not to repair organic exhaustion nor to provide sound functioning of the organs. All this supraphysical life is built and expanded not because of the demands of the cosmic environment but because of the demands of the social environment.

Socialism is not a science, a sociology in miniature: it is a cry of pain.

The man whose whole activity is diverted to inner meditation becomes insensible to all his surroundings.