Carl Georg Lange (1834 - 1900) is a Psychologue and Physicien Danish. Doctor of medicine, Carl Lange follows studies in psychology. He works out in 1884 in the same time as William James, his version of the theory of the emotion: Theory James-Lange . For them, the emotion translates a physiological answer to the modifications. Quotation: “We feel sad because we cry, in anger because we strike somebody and frightened because we tremble. ”