Friedrich Engels Funeral Oration for Marx

Just as Darwin discovered the law of evolution in organic nature, so Marx discovered the law of evolution in human history; he discovered the simple fact, hitherto concealed by an overgrowth of ideology, that mankind must first of all eat and drink, have shelter and clothing, before it can pursue politics, science, religion, art, etc, and that therefore the production of the immediate material means of subsistence and consequently the degree of economic development attained by a given people or during a given epoch, form the foundation upon which the state institutions, the legal conceptions, the art and even the religious ideas of the people concemed have been evolved, and in the light of which these things must therefore be explained, instead of vice versa as had hitherto been the case. But that is not all. Marx also discovered the special law of motion governing the present-day capitalist mode of production and the bourgeois society that this mode of production has created. The discovery of surplus value suddenly threw light on the problem in trying to solve which all previous investigators, both bourgeois economists and socialist critics, had been groping in the dark. Two such discoveries would be enough for one life¬ time. Happy the man to whom it is granted to make even one such discovery. But in every single field which Marx investigated—and he investigated very many fields, none of them superficially—in every field, even in that of mathematics, he made independent discoveries. Such was the a historically dynamic, revolutionary force. However great the joy with a historically dynamic, revolutionary force. However great the joy with which he welcomed a new discovery in some theoretical science whose practical application perhaps it was as yet quite impossible to envisage, he experienced quite another kind of joy when the discovery involved immediate revolutionary changes in industry and in the general course of history.

Marx discovered the law of evolution in human history, how memes took over from our genes if social circumstances allow for it.