By bourgeoisie is meant the class of modern capitalists, owners of the means of social production and employers of wage labor. By proletariat, the class of modern wage laborers who, having no means of production of their own, are reduced to selling their labor power in order to live.

Thus at every step we are reminded that we by no means rule over nature like a conqueror over a foreign people, like someone standing outside nature - but that we, with flesh, blood and brain, belong to nature, and exist in its midst, and that all our mastery of it consists in the fact that we have the advantage over all other creatures of being able to learn its laws and apply them correctly.

If in all ideology men and their circumstances appear upside-down as in a camera obscura, this phenomenon arises just as much from their historical life-process as the inversion of objects on the retina does from the physical life-process.

It is a curious fact that with every great revolutionary movement the question of 'free love' comes into the foreground.

All that is real in human history becomes irrational in the process of time.

It is no longer a question anywhere of inventing interconnections from out of our brains, but of discovering them in the facts.

The state is nothing but an instrument of opression of one class by another - no less so in a democratic republic than in a monarchy.