And, from another point of view, what is the famous doctrine of “class-struggle” which Marx revealed as the positive key of human history, but the Darwinian law of the “struggle for life” transformed from a chaotic strife between individuals to a conflict between collectivities?

Just the same as every individual, every class or social group struggles for its existence.  And just as the bourgeoisie struggled against the clergy and the aristocracy, and triumphed in the French Revolution, in the same way to-day the international proletariat struggles, and not by the use of violence, as is constantly charged against us, but by propaganda and organization for its economic and moral existence at present so ill assured and depressed to so sadly low a plane.

As regards the theory of evolution, how can any one not see that it most flagrantly contradicts the classical theories of political economy, which looks upon the basic laws of the existing economic organization as eternal and immutable laws?

Socialism, on the contrary, maintains that the economic institutions and the juridical and political institutions are only the historical product of their particular epoch, and that therefore they are changing, since they are in a state of continuous evolution, which causes the present to differ from the past, just as the future will be different from the present.

Herbert Spencer believes that universal evolution dominates over all orders of phenomena, with the exception of the organization of property, which he declares is destined to exist eternally under its individualistic form.  The socialists, on the contrary, believe that the organization of property will inevitably undergo—­just as all other institutions—­a radical transformation, and, taking into consideration its historical transformations, they show that the economic evolution is marching and will march faster and faster—­as a consequence of the increased evils of individualist concentration—­toward its goal, the complete socialization of the means of production which constitute the physical basis of the social and collective life, and which must not and can not therefore remain in the hands of a few individuals.

Between these two doctrines it is not difficult to decide which is the more in harmony with the scientific theory of physical and social evolution.

In any case, with all the respect due to our intellectual father, Herbert Spencer, but also with all the pride to which my scientific studies and conscience give me the right, I am content with having repelled the anathema which Herbert Spencer—­without having read my book and on indirect and untrustworthy information—­has thought proper to hurl with such a dogmatic tone against a scientific thesis which I have affirmed—­not merely on the strength of an ipse dixi (a mode of argument which has had its day)—­but which I have worked out and supported with arguments which have, up to this time, awaited in vain a scientific refutation.