Summary In establishing what he called the metaphysics of science , the French naturalist Buffon was confronted with the problem of situating the place occupied by man in the natural world, a problem which ultimately depended on discerning his true nature. The paradox of Descartes' dualism offered various solutions — the extremes being, either to condemn man's material nature as corrupted in order to exalt his spiritual nature as a moral being, as Pascal had done, or to reduce man's pretended (...) spiritual nature to nothing more than a manifestation of his material organization, the solution of La Mettrie. Buffon could accept neither, proves man's duality, and proceeds to establish his gnoseological principle on his critique of these two radical solutions. (shrink)