In proportion as the bourgeoisie, i.e., capital, is developed, in the same proportion is the proletariat, the modern working class, developed - a class of labourers, who live only so long as they find work, and who find work only so long as their labour increases capital. These labourers, who must sell themselves piecemeal, are a commodity, like every other article of commerce, and are consequently exposed to all the vicissitudes of competition, to all the fluctuations of the market.

There is no royal road to science, and only those who do not dread the fatiguing climb of its steep paths have a chance of gaining its luminous summits. (Preface to the French edition).

Necessity is blind until it becomes conscious. Freedom is the consciousness of necessity.

There are no bigger donkeys than these workers.... Look at our 'craftsmen'; Sad that world history should be be made with such people.

...the French Revolution gave rise to ideas which led beyond the ideas of the entire old world order. The revolutionary movement which began in 1789... gave rise to the communist idea which Babeuf's friend Buonarroti re-introduced in France after the Revolution of 1830. This idea, consistently developed, is the idea of the new world order.

Keep people from their history, and they are easily controlled.

...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.