"We are not interested in the future for its own sake, but only in so far as it affects the present."

"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."

"Freedom does not consist in any dreamt-of independence from natural laws, but in the knowledge of these laws, and in the possibility, therefore, of putting them to work purposefully for definite ends."

"The English working class is, after all, only a branch of the German working class."

"All that is solid melts into air."