The first class opposition that appears in history coincides with the development of the antagonism between man and woman in monogamous marriage, and the first class oppression coincides with that of the female sex by the male.

The way in which the vast mass of the poor are treated by modern society is truly scandalous. They are herded into great cities where they breathe a fouler air than in the countryside which they have left.

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

One day we shall certainly 'reduce' thought experimentally to molecular and chemical motions in the brain; but does that exhaust the essence of thought?

Ideas often kindle each other, like electrical sparks.

Freedom is the recognition of necessity.

We discovered that in connection with these figures the German national simpletons and money-grubbers of the Frankfurt parliamentary swamp always counted as Germans the Polish Jews as well, although this dirtiest of all races, neither by its jargon nor by its descent, but at most only through its lust for profit, could have any relation of kinship with Frankfurt.