Now one great fact, above all others, dominates the period in which the positive philosophy appeared. It is the French Revolution, as Comte expressly states: without it, neither the theory of progress, nor consequently social science, nor consequently again positive philosophy would have been possible. Was it not, moreover, inevitable that this extraordinary social upheaval should by reflex action have determined a vast and prolonged movement in philosophical and political speculation? The effects of this reflex action varied according to the value and the originality of the minds which experienced them. But in the greatest as in the most mediocre we recognise infallibly certain common features. For instance, men and women, in the rising generation at the beginning of the XIX. century, never fail to put the same question to themselves: “What social institutions should be established after the Revolution?” and by this all understand not only the political form of government, but the very principles of social order: a problem which appeared as urgent from the practical point of view, as it was supreme from the theoretical point of view. It is this problem in various forms which preoccupies Chateaubriand as well as Fourier and Saint-Simon, and Joseph de Maistre as well as Cousin and Comte. All agree upon the first point. We must “reconstruct.” An “organic” period must succeed the “critical” period which has just come to an end. According to Saint Simon’s striking expression, humanity is not made to inhabit ruins. The revolutionary storm had been so formidable, the din so deafening, the social back-wash so violent, that no one exactly measured the effect which had been produced. Many institutions which had only been shaken seemed to be overthrown. A good part of the old régime had even gone through the crisis without being too greatly damaged, and had survived. But this fact, which was very well appreciated by the men of 1850, could not yet be discovered by the first generation of the century. It conscientiously believed that the old régime had crumbled altogether, and that the task either of restoring it, or of again laying down the very bases of society belonged to it. In this the first generation remained faithful to the spirit of the Revolution, which had considered itself as an effort to institute an entirely new social and political system, a thought in which the civilised world had shared. Now, in spite of the labours of the revolutionary assemblies, in spite of the power and of the great talent which the Convention had at its command, this ambitious hope had not been realised. The question remained open after the Directoire and after the Empire. When the old régime was supposed to have been destroyed, how was society to be “reorganised”?