And finally, these connections between the productivity of labor and the co-ordination of those who co-operate in it are changed with the changing of the instruments--in the broad sense of the word--necessary to production. The _processes_ and the progress of technique, as they are the index, are also the condition of all the other _processus_ and of all progress. Society is for us a fact, which we cannot solve, unless it be by that analysis which reduces the complex forms to the simpler forms, the modern forms to the older forms: but that is to remain always, nevertheless, in a society which exists. History is but the history of society--that is to say, the history of the variations of human co-operation, from the primitive horde down to the modern State, from the immediate struggle against nature, by the means of a few very simple tools, down to the present economic structure, which reduces itself to these two poles; accumulated labor (capital) and living labor (proletarians). To resolve the social _complexus_ into simple individuals, and to reconstruct it afterwards by the acts of free and voluntary thought; to construct, in fine, society with its reasons, is to misunderstand the objective nature and the immanence of the historic _processus_. Revolutions, in the broadest sense of the word, and in the specific sense of the destruction of a political organization, mark the real and proper dates of historic epochs. Seen from afar, in their elements, in their preparation and their effects, at long range, they may appear to us as moments of a constant evolution, with minute variations; but considered in themselves, they are definite and precise catastrophes, and it is only as catastrophes that they are historic events. X. Ethics, art, religion, science, are they then but products of economic conditions?--expositions of the categories of these very conditions?--effluvia, ornaments, emanations and mirages of material interests? Affirmations of this sort, announced with this nudity and crudity, have already for some time passed from mouth to mouth, and they are a convenient assistance to the adversaries of materialism, who use them as a bugbear. The slothful, whose number is great even among the intellectuals, willingly fit themselves to this clumsy acceptance of such declarations. What a delight for all careless persons to possess, once for all, summed up in a few propositions, the whole of knowledge, and to be able with one single key to penetrate all the secrets of life! All the problems of ethics, aesthetics, philology, critical history and philosophy reduced to one single problem and freed thus from all difficulties! In this way the simpletons might reduce the whole of history to commercial arithmetic; and finally a new and authentic interpretation of Dante might give us the Divine Comedy illustrated with the process of manufacturing pieces of cloth which the wily Florentine merchants sold for their greater profit!