The author seeks to show that Freud's fundamental concepts of how the psyche works (the unconscious and the process of après-coup) are not invalidated by the so-called rational sciences, but are in fact precursors in these fields of research. She examines the thorny issue of the relationship between the body and the mind, and more specifically between the brain and thought, a truly multidisciplinary challenge. Through his study of hysteria, Freud seems to have rejected the Project and lost interest in neurology when he realized that neuronal events were not isomorphic to psychological events. His intuition regarding the primacy of unconscious processes is now a fundamental hypothesis in neuroscience and cognitive psychology. The paradox of the process of après-coup, with its retroactive effect, is found in neurophysiology (the backdating of delayed sensory experience) and quantum physics (delayed choice).