The aim of this paper is to clarify Paul Valéry’s idea of purity of poetry in relation to his thought on physiology. Curiously Valéry found that the ideal type of artistic experience was a physiological phenomenon related to the nature of the retina. This phenomenon was the perception of complementary colors. Complementary colors produced by the eye as “antidote” against colors that stimulate it are certainly subjective impressions and may become unsettling factors to objective recognition. However, Valéry regarded this pure sensation set free from external objects of reference as a mode of perception of our own body whose functions would otherwise be imperceptible. Indeed, we directly find out about our body only when it doesn’t function properly. By using means such as rhythm, rhyme, inversion and surprise, poetry captures the reader’s body and interferes with its smooth, automatic, and somehow prosaic activity. This is the point where pure poetry and physiology intersect. Both help us to construct a representation of our body by drawing our attention to physical unsettling. The body, according to Valéry’s idea, emerges thus as a system consisting of various functions.