The masses are in reality their own leaders, dialectically creating their own development process.

Self-criticism, cruel, unsparing criticism that goes to the very root of the evil, is life and breath for the proletarian movement.

[Geology] opens up such wide intellectual vistas and supplies a more perfectly unified and more comprehensive conception of nature than any other science.

Freedom is always and exclusively freedom for the one who thinks differently.

We will be victorious if we have not forgotten how to learn.

Being human means throwing your whole life on the scales of destiny when need be, all the while rejoicing in every sunny day and every beautiful cloud.

The working classes in every country only learn to fight in the course of their struggles.