Life is the mode of action of proteins.

In a political struggle of class against class, organization of trade unions is the most important weapon.

Freedom does not consist in any dreamt-of independence from natural laws, but in the knowledge of these laws, and in the possibility this gives of systematically making them work towards definite ends.

Don't forget any affront done to you and to all our people, the time of revenge will come and must be put to good use.

It is no longer a question anywhere of inventing interconnections from out of our brains, but of discovering them in the facts.

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.

Three hundred years after its appearance Christianity was the recognized state religion in the Roman World Empire, and in barely sixty years socialism has won itself a position which makes its victory absolutely certain.