Just as Marx used to say about the French Marxists of the late 'seventies: All I know is that I am not a Marxist.

Everything must justify its existence before the judgment seat of Reason, or give up existence.

Life is the mode of action of proteins.

In science, each new point of view calls forth a revolution in nomenclature.

What each individual wills is obstructed by everyone else, and what emerges is something that no one willed.

Freedom does not consist in any dreamt-of independence from natural laws, but in the knowledge of these laws, and in the possibility this gives of systematically making them work towards definite ends.

The proletarians, driven to despair, will seize the torch which Stephens has preached to them; the vengeance of the people will come down with a wrath of which the rage of 1795 gives no true idea. The war of the poor against the rich will be the bloodiest ever waged.