Why did Foucault criticize the idea that “man” is a timeless category?

Michel Foucault criticized the idea that "man" is a timeless category because he viewed it as a recent, historically contingent invention rather than an immutable essence. In his work The Order of Things, Foucault argued that the concept of "man"—as a creature possessing a dual nature as both an object of scientific study and a free subject—emerged only during a specific shift in Western "epistemes" or discursive regimes around the turn of the 19th century.12

Foucault’s skepticism was rooted in his historical analysis, which revealed that conceptions of human beings vary dramatically across time and place. He contended that the "man" of the human sciences was a conceptual prerequisite for modern social institutions and practices, such as those found in discipline and biopolitics, which sought to manipulate and reform populations. By framing "man" as a product of historically specific power-knowledge dynamics, Foucault aimed to expose the artificiality of this figure and suggest that it would eventually disappear as knowledge systems evolve.21