Isidore Auguste Marie Francois Xavier Comte (1798-1857) was the leader of the positivist school in France. He was one of the founders of sociology. Comte developed a humanist religion that called for the replacement of God with a supreme being who was centered on the essence of humanity. Although he was overshadowed by figures such as Marx, Comte influenced diverse thinkers including George Eliot and John Stuart Mill.

Comte was born in Montpellier, France, to a staunch Royalist and Roman Catholic family who rejected the republicanism of the French Revolution. He entered the Ecole Polytechnique at age 16, but he rejected the royalism of his family. After being expelled from the Polytechnique, Comte settled in Paris where he became the secretary to the reformer and socialist Claude-Henri de Saint-Simon. While with Saint-Simon, Comte worked with his mentor to develop a science of human behavior. Comte broke with Saint-Simon in 1824 and gained his own fame after he delivered a series of lectures on positivism.

These lectures provided the basis for Comte's greatest work, Cours de philosophie positive (Course of Positive Philosophy). The six-volume work was written between 1830 and 1842. In his opus, Comte asserted that each science needed its own methodology and that each science is dependent on its antecedents. Hence, philosophy is dependent on history, physics dependent on astronomy, and so forth. He contended that each science goes through three distinct phases: theological (where humans view nature and natural law as dependent on the will of a deity); metaphysical (cause and effect begin to replace divine will); and positive (the quest for absolute knowledge of an area). Comte's positivism manifested itself in the belief that progress was both irreversible and inevitable. However, he did not believe that humans could obtain perfect knowledge.

Comte helped develop the modern discipline of sociology (and he coined the term sociology). He contended that sociology had not yet entered the positive stage but that it ultimately would clarify the other sciences. Sociology would be able to provide a framework by which social customs and traits could be quantified into laws. He envisioned the modern division of sociology into two distinct branches: social statics, or the comparative study of different social systems; and social dynamics, or the study of social change. Comte also differentiated between order and progress. Order was marked by consensus on the fundamental principles of a society, while progress was marked by change in the underlying principles as had been the case in Europe from the Reformation through the French Revolution. Comte asserted that a synthesis of order and progress could produce a global society that would not fight over religious or political differences. Comte's later works included the 1848 book Discours sur l'Ensemble du positivisme (A General View of Positivism), and the 1851 piece, Systeme de politique positive (System of Positive Polity).

In Comte's estimation, the events of the French Revolution had been negative in that they had broken down the old order but had not produced a new one. He advocated a new religion of humanity that would be led by an industrial-elite priesthood and that would have as its highest deity a supreme being who combined the essence of existence with the harmony of nature. Scientific principles would guide everyday life, and Comte devised a new calendar based on honoring 13 great thinkers, including Aristotle, Dante, and Shakespeare.