The product of mental labor - science - always stands far below its value, because the labor-time necessary to reproduce it has no relation at all to the labor-time required for its original production.

Accumulation of wealth at one pole is at the same time accumulation of misery, agony of toil, slavery, ignorance, brutality, mental degradation, at the opposite pole

The criticism of Religion is the beginning of all criticism

Wages are determined by the bitter struggle between capitalist and worker.

When commercial capital occupies a position of unquestioned ascendancy, it everywhere constitutes a system of plunder.

You are horrified at our intending to do away with private property. But in your existing society, private property is already done away with for nine tenths of the population; its existence for the few is solely due to its non-existence in the hands of those nine tenths. You reproach us, therefore, with intending to do away with a form of property, the necessary condition for whose existence is the non-existence of any property for the immense majority of society.

All freed, fast-frozen relations, with their train of ancient and venerable prejudices and opinions, are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned, and man is at last compelled to face with sober senses, his real conditions of life, and his relations with his kind.