The 19th century was a century represented by its actors as one of irreversible progress – one that the advance of the sciences was driving towards an increasingly developed future. In this future, it was thought, knowledge would allow man to emancipate himself once and for all; he would be freed from the heaviest and most punishing tasks, which would be carried out by machines and other new technologies. The control of fossil fuels allowed for the invention of the train, and electricity appeared, as did photography and the telegraph. Medicine progressed. Scientific research permitted an increasing number of illnesses to be cured and treated through, for example, the first vaccines, which were enabled by Pasteur’s discoveries. Amid this effervescence, science found itself placed at the centre of all scholarly thought, ripe for theorisation. The advances of chemistry, physics and biology fascinated those who Honneth has rightly called philosophers of the social (1994). And at the time, more than one of these philosophers envisaged the application of natural science’s methods to the study of human societies. The idea that it is possible to identify the principal natural laws that govern the development of human groups – just like it is possible to identify the laws that govern the physical world (in order to control it) – gained ground. Saint-Simon (1760-1825), envisaged a social physiology whose task would be to observe social phenomena as we observe natural phenomena. But it was Auguste Comte (1798-1857) who, theorising what we still understand today as sociology, would endorse the particular stand of social philosophy that constituted positivism.