The bourgeoisie cannot exist without constantly revolutionizing the instruments of production, and thereby the relations of production, and with them the whole relations of society.

The human being is in the most literal sense a political animal, not merely a gregarious animal, but an animal which can individuate itself only in the midst of society.

Once the inner connection is grasped, all theoretical belief in the permanent necessity of existing conditions collapses before their collapse in practice -- Letter to Ludwig Kugelmann (July 11, 1868)

The whole proletariat must be armed at once with muskets, rifles, cannon and ammunition, and the revival of the old-style citizens militia, directed against the workers, must be opposed.

A man cannot become a child again, or he becomes childish.

Every provisional political set-up following a revolution requires a dictatorship, and an energetic dictatorship at that.

Force is the midwife of every old society pregnant with a new one.