Whatever may be the case, the first subject which seriously occupied his mind was mathematics. Being admitted to the _Ecole polytechnique_ a year before the usual age, he began to study the natural sciences. At the same time he “meditates” upon Montesquieu and Condorcet. He approaches philosophy properly so called by reading the Scottish philosophers, Ferguson, Adam Smith, Hume, and he sees very well that the last one is far above the others. Having left the _Ecole polytechnique_, he remains in Paris, and while giving lessons to earn his living, he completes his scientific education with Delambre, de Blainville, and the Baron Thénard. He reads assiduously Fontenelle, d’Alembert, Diderot, and especially Condorcet who has distilled and clarified the philosophy of the XVIII. century. While studying Descartes and the great mathematicians who came after him, he also follows attentively the labours of naturalists and of biologists, of Lamarck, for instance, of Cuvier, of Gall, of Cabanis, of Bichat, Broussais and of so many others. He understands the philosophical importance of these new sciences, as already pointed out by Diderot. But for all that he does not neglect historical and social studies. He has read the ideologists, among whom he especially esteemed Destutt de Tracy. Without giving up Montesquieu or Condorcet, he studies the traditionalists: M. de Bonald, this “energetic thinker” and, more than the others, Joseph de Maistre who made the deepest and most enduring impression upon his mind. Before knowing Saint-Simon then--and his correspondence with Valat testifies to the fact--Comte already possessed a large portion of the materials for his future system. Up to this time his labours had borne upon two distinct orders of subjects. The one scientific proper (mathematics, physics and chemistry, natural sciences) the other more properly political (history, politics, and social questions). In 1818 Comte meets Saint-Simon. He is attracted and surrenders himself almost unreservedly. For four years he works with Saint-Simon. He loves and venerates him as a master. He feeds upon his ideas, and collaborates in his labours and enterprises. He calls himself “pupil of M. Saint-Simon.” However, from 1822 he detaches himself from this greatly-admired master, and in 1824 the rupture is complete and final. What can have happened?