 Auguste Comte (1798–1857) is the founder of positivism, a philosophical and political movement which enjoyed a very wide diffusion in the second half of the nineteenth century. It sank into an almost complete oblivion during the twentieth, when it was eclipsed by neopositivism. However, Comte’s decision to develop successively a philosophy of mathematics, a philosophy of physics, a philosophy of chemistry and a philosophy of biology, makes him the first philosopher of science in the modern sense, and his constant attention to the social dimension of science resonates in many respects with current points of view. His political philosophy, on the other hand, is even less known, because it differs substantially from the classical political philosophy we have inherited.