This is the great discovery which the genius of Karl Marx has expounded in his Critique de l’economie politique.  I will examine further on the question as to what this sole source or basis of the varying economic conditions is, but the important point now is to emphasize their constant variability, from the pre-historic ages down to historical times and to the different periods of the latter.

Moral codes, religious creeds, juridical institutions both civil and criminal, political organization:—­all are constantly undergoing transformation and all are relative to their respective historical and material environments.

To slay one’s parents is the greatest of crimes in Europe and America; it is, on the contrary, a duty enjoined by religion in the island of Sumatra; in the same way, cannibalism is a permitted usage in Central Africa, and such it also was in Europe and America in pre-historic ages.

The family is, at first (as among animals), only a sort of sexual communism; then polyandry and the matriarchal system were established where the supply of food was scanty and permitted only a very limited increase of population; we find polygamy and the patriarchal system appearing whenever and wherever the tyranny of this fundamental economic cause of polyandry ceases to be felt; with the advent of historical times appears the monogamic form of the family the best and the most advanced form, although it is still requisite for it to be freed from the rigid conventionalism of the indissoluble tie and the disguised and legalised prostitution (the fruits of economic causes) which pollute it among us to-day.

How can any one hold that the constitution of property is bound to remain eternally just as it is, immutable, in the midst of the tremendous stream of changing social institutions and moral codes, all passing through evolutions and continuous and profound transformations?  Property alone is subject to no changes and will remain petrified in its present form, i. e., a monopoly by a few of the land and the means of production![48]

This is the absurd contention of economic and juridical orthodoxy.  To the irresistible proofs and demonstrations of the evolutionist theory, they make only this one concession:  the subordinate rules may vary, the abuses may be diminished.  The principle itself is unassailable and a few individuals may seize upon and appropriate the land and the means of production necessary to the life of the whole social organism which thus remains completely and eternally under the more or less direct domination of those who have control over the physical foundation of life.[49]

Nothing more than a perfectly clear statement of the two fundamental theses—­the thesis of classical law and economics, and the economic and juridical thesis of socialism—­is necessary to determine, without further discussion, this first point of the controversy.  At all events, the theory of evolution is in perfect, unquestionable harmony with the inductions of socialism and, or the contrary, it flatly contradicts the hypothesis of the absoluteness and immutability of the “natural” laws of economies, etc.