Talk by Robin Carhart-Harris at the conference "Études psychédéliques - approche historique de la construction d'un champ disciplinaire" organized by the French Psychedelic Society on May 9, 2018 at the Muséum national d'Histoire naturelle in Paris, with the support of the Centre Alexandre-Koyré, the Institut des humanités en médecine, the Société des amis du Muséum, the HAR research team and UMR TELEMMe. At the public launch of the French Psychedelic Society, Robin Carhart-Harris (Imperial College London) detailed the mechanisms of psychedelics in the mind and brain. He discussed topics such as the effect of serotonin 2A receptors agonism, the function of serotonin 2A receptors agonism, the acute effects of psychedelics on human brain, the entropic brain activity, the psychedelic therapy, the entropic and bayesian brain, context sensitivity, psychedelics insights, the evolutionary and developmental function of 5-HT2A receptors. https://societepsychedelique.fr / psysocfr / sopsyfra [email protected]