You cannot make a socialist revolution without really trying.

Mistakes in themselves are unavoidable.

Only under conditions of revolutionary crises do you have the highest level of self-organization; this is the Soviet type of organization, which is to say, workers' councils, people's councils, call them what you want, popular committees.

For us, Marxism is always open because there are always new experiences, there are always new facts, including facts about the past, which have to be incorporated in the corpus of scientific socialism.

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

And you cannot have a socialist revolution commandeered from the top, ordered around by some omniscient leader or group of leaders

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