The working class is revolutionary or it is nothing.

In this sense, the theory of the Communists may be summed up in the single sentence: Abolition of private property. - Manifesto of the Communist Party

...the very cannibalism of the counterrevolution will convince the nations that there is only one way in which the murderous death agonies of the old society and the bloody birth throes of the new society can be shortened, simplified and concentrated, and that way is revolutionary terror.

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.

History repeats itself, the first as tragedy, then as farce.

History calls those men the greatest who have ennobled themselves by working for the common good; experience acclaims as happiest the man who has made the greatest number of people happy.

Labor, being itself a commodity, is measured as such by the labor time needed to produce the labor-commodity. And what is needed to produce this labor-commodity? Just enough labor time to produce the objects indispensable to the constant maintenance of labor, that is, to keep the worker alive and in a condition to propagate his race. The natural price of labor is no other than the wage minimum.