Periodically, the workers do revolt against bourgeois society, not by a hundred, five hundred, or a thousand, but by the millions.

Revolution is an instrument, like a party is an instrument.

There is a process of social and of political differentiation going on in the real working class all the time.

Mistakes in themselves are unavoidable.

There has been hardly a single year since 1917, and in a certain sense since 1905, without a revolution somewhere in the world in which the workers participated in a rather important way.

Revolution is not a goal in itself.

For Marx, 'pure' economic theory, that is economic theory which abstracts from a specific social structure, is impossible.