These formulae indeed do not permit us to explain, by the immediate examination of the various interests which are at its base, every particular law which has appeared in history. The facts of history are very complicated; but these general formulae suffice to indicate the style and the method of research which has been substituted for legal ideology. IX. Here I must give certain formulae. Granted the conditions of the development of labor and the instruments appropriated to it, the economic structure of society, that is to say, the form of production of the immediate means of life, determines, on an artificial field, _in the first place and directly_, all the rest of the practical activity of those associated, and the variation of this activity in the _processus_ which we call history, that is to say:--the formation, the frictions, the struggles and the erosions of the classes;--the corresponding regulations relative to law and morality;--and the reasons and modes of subordination and subjection of men toward men and the corresponding exercise of dominion and authority, in fine, that which gives birth to the State and that which constitutes it. It determines, _in the second place_, the tendency and in great part, _in an indirect fashion_, the objects of imagination and of thought in the production of art, religion and science. The products of the _first_ and of the _second stage_, in consequence of the interests which they create, the habits which they engender, the persons whom they group and whose spirit and inclinations they specify, tend to fix themselves and isolate themselves as independent entities; and thence comes that empirical view, according to which different independent factors, having an efficacy and a rhythmic movement of their own, contribute to form the historic _processus_ and the social configurations which successively result from it. It is the social classes, in so far as they consist in differentiations of interests, which unfold in definite ways and in forms of opposition (--whence come the friction, the movement, the process and the progress--), which have been the factors--if it was ever necessary to employ this expression:--the real, proper and positive factors of history, from the disappearance of primitive communism until to-day. The variations of the underlying (economic) structure of society which, at first sight, show themselves intuitively in the agitation of the passions, develop consciously in the struggles against law and for law, and become realized in the shaking and in the ruin of a definite political organization, have in reality their adequate expression only in the change in the relations which exist between the different social classes. And these relations change with the change of the relations which previously existed between the productivity of labor and the (legal-political) conditions of co-ordination of those who co-operate in production.