French philosopher, the closest disciple of the philosopher Auguste Comte, who taught in his doctrine of Positivism that only knowledge verifiable by the methods of the empirical sciences is valid.

On Comte's death in 1857, Laffitte, who was one of his executors, became head of the Comité Positiviste. He was appointed professor of the general history of science at the Collège de France in 1892. His works include Leçons de cosmographie (1853; “Lectures on Cosmography”), Cours philosophique sur l'histoire générale de l'humanité (1859; “Philosophic Course on the General History of Man”), Considérations générales sur l'ensemble de la civilisation chinoise (1861), Les Grands types de l'humanité (1874; “The Great Symbols of Man”), De la morale positive (1880; “On the Positivist Ethic”), and Le “Faust” de Goethe (1899; “The ‘Faust' of Goethe”).