Abstract
While the scientific contributions of François Jacob were outstanding, I also consider that his conception of science, and of its place among other forms of knowledge, is also highly original, and important for the future of science in our societies. His contributions to the history and philosophy of science were neither a hobby nor a secondary activity, but they were for him a natural complement to his scientific work. He fully opposed the concept of the two cultures, the literary and the scientific, proposed by C.P. Snow. For Jacob, concepts, metaphors and models circulated between the various spheres of human activity. This is obvious in his own work. This “open” conception of scientific activity did not prevent him from defending the specificity, and the superiority, of scientific knowledge.