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.

...it was always our view that in order to attain this [proletarian revolution] and the other far more important aims of the future social revolution, the working class must first take possession of the organised political power of the state and by its aid crush the resistance of the capitalist class and organise society anew.

Labour is the source of all wealth, the political economists assert. And it really is the source -- next to nature, which supplies it with the material that it converts into wealth. But it is even infinitely more than this. It is the prime basic condition for all human existence, and this to such an extent that, in a sense, we have to say that labour created man himself.

Just as Marx used to say about the French Marxists of the late 'seventies: All I know is that I am not a Marxist.

By the same right under which France took Flanders, Lorraine and Alsace, and will sooner or later take Belgium — by that same right Germany takes over Schleswig; it is the right of civilisation as against barbarism, of progress as against stability.

Life is the mode of action of proteins.

People have learned by bitter experience that the "European fraternal union of peoples" cannot be achieved by mere phrases and pious wishes, but only by profound revolutions and bloody struggles; they have learned that the question is not that of a fraternal union of all European peoples under a single republican flag, but of an alliance of the revolutionary peoples against the counter-revolutionary peoples, an alliance which comes into being not on paper, but only on the battlefield.