 The resumption of the Course of Positive Philosophy in January 1829, marks the beginning of a second period in Comte’s life that lasted 13 years and included the publication of the six volumes of the Course (1830, 1835, 1838, 1839, 1841, 1842). In addition, during this period, more and more of his ties with the academic world were severed. After being named tutor in analysis and mechanics at the École Polytechnique in 1832, in 1833 he sought to create a chair in general history of science at the Collège de France, but to no avail. Two unsuccessful candidacies for the rank of professor at the École Polytechnique led him in 1842 to publish a ‘personal preface’ to the last volume of the Course, which put him at odds with the university world forever. The two years that followed mark a period of transition. In quick succession, Comte published an Elementary Treatise on Analytic Geometry (1843), his only mathematical work, and the Philosophical Treatise on Popular Astronomy (1844), the fruit of a yearly course, begun in 1830, for Parisian workers. The Discourse on the Positive Spirit, also from 1844, which he used as the preface to the treatise on astronomy, marked a sharp change of direction by its emphasis on the moral dimension of the new philosophy: now that the sciences had been systematized, Comte was able to return to his initial interest, political philosophy. Public recognition of the positivist Comte, as opposed to the saint-simonian, twenty years earlier, came with Émile Littré’s articles in Le National.