Was Norbert Wiener a metaphysician?

Relying on a careful analysis of Norbert Wiener's implicit philosophy, this article aims at showing the presence of a palpable tension in his general conception of human beings. Wiener saw no essential difference between living and non-living beings and even less between human and non-human beings. He explicitly and repeatedly made this claim. Furthermore, he defines us as sophisticated machines. But, how then can there be unsurpassable machines, as he said in many writings? I will try to find ways to answer this question. The thesis of this article is that the presence of some contradictions in Wiener's philosophy testfies to a strong tension between two poles fighting in him. A tension that marked his life as a thinker : a tension between the scientfic mathematician and the philosophical metaphysician.