Michel Foucault argues that, before the XIX century, the Man as we know didn’t exist. What existed was a group of knowledges, reflections and problems related to nature, order, truth, etc. but it was never a matter of the Man.
At the end of the XVIII century, the concept of humanism was invented. It was in this term that Marxism and the existentialists found roots for their theories. Paradoxically, the development of human sciences conducts us to the disappearance rather than an apotheosis of Man. As an example, Foucault gives the study of Lévi-Strauss and others about human behaviour and concluded that Man is actually being seen as a thought-system, as organisations. Man would be just a glance at the surface of big structural and formal systems, losing their individuality and their own existence.
Therefore, Foucault’s argument is that, in ancient ages, the Man was not the focus of thought. The main philosophical questions were about nature and the divine, exploring the world that surrounds us. From the end of the XVIII until the first half of the XX century, Man was invented and became the great concept of thought of this age. From mid-XX, Man as previously known, started to disappear, once the perspective changed towards a more structuralist way of thought, blending the human with systematic organisation, making men loose their individualistic touch. These phases can be seen through the human arts and thoughts production throughout history.
Interview with Michel Foucault: https://www.youtube.com/watch?v=hem1er1VJUQ