Positivism consists essentially of a Philosophy and a Polity. These can never be dissevered; the former being the basis, and the latter the end of one comprehensive system, in which our intellectual faculties and our social sympathies are brought into close correlation with each other. For, in the first place, the science of Society, besides being more important than any other, supplies the only logical and scientific link by which all our varied observations of phenomena can be brought into one consistent whole[1]. Of this science it is even more true than of any of the preceding sciences, that its real character cannot be understood without explaining its exact relation in all general features with the art corresponding to it. Now here we find a coincidence which is assuredly not fortuitous. At the very time when the theory of society is being laid down, an immense sphere is opened for the application of that theory; the direction, namely, of the social regeneration of Western Europe. For, if we take another point of view, and look at the great crisis of modern history, as its character is displayed in the natural course of events, it becomes every day more evident how hopeless is the task of reconstructing political institutions without the previous remodelling of opinion and of life. To form then a satisfactory synthesis of all human conceptions is the most urgent of our social wants: and it is needed equally for the sake of Order and of Progress. During the gradual accomplishment of this great philosophical work, a new moral power will arise spontaneously throughout the West, which, as its influence increases, will lay down a definite basis for the reorganization of society. It will offer a general system of education for the adoption of all civilized nations, and by this means will supply in every department of public and private life fixed principles of judgment and of conduct. Thus the intellectual movement and the social crisis will be brought continually into close connexion with each other. Both will combine to prepare the advanced portion of humanity for the acceptance of a true spiritual power, a power more coherent, as well as more progressive, than the noble but premature attempt of mediaeval Catholicism. The primary object, then, of Positivism is two-fold: to generalize our scientific conceptions, and to systematize the art of social life. These are but two aspects of one and the same problem. They will form the subjects of the two first chapters of this work. I shall first explain the general spirit of the new philosophy. I shall then show its necessary connexion with the whole course of that vast revolution which is now about to terminate under its guidance in social reconstruction.