Since only what is material is perceptible, knowable, nothing is known of the existence of God.

When the sufferers learn to think, then the thinkers will learn to suffer.

The history of all previous societies has been the history of class struggles.

The ideas of the ruling class are in every epoch the ruling ideas, i.e., the class which is the ruling material force of society, is at the same time its ruling intellectual force.

Religion is only the illusory sun which revolves round man as long as he does not revolve round himself.

Darwin's book is very important and serves me as a basis in natural science for the class struggle in history. One has to put up with the crude English method of development, of course. Despite all deficiencies not only is the death-blow dealt here for the first time to 'teleology' in the natural sciences, but their rational meaning is empirically explained.

The most interesting acquaintanceship I have struck up here is that of Colonel Lapinski. He is without doubt the cleverest Pole - besides being an homme d'action [man of action] - that I have ever met. His sympathies are all on the German side, though in manners and speech he is also a Frenchman. He cares nothing for the struggle of nationalities and only knows the racial struggle. He hates all Orientals, among whom he numbers Russians Turks, Greeks, Armenians, etc., with equal impartiality.... His aim now is to raise a German legion in London.