Les Neurosciences au XVIIe siècle (ou l'erreur de Damasio)

Abstract

In his book, Descartes' error, Antonio R. Damasio attributes the separation of mind and body in Western medicine to Descartes' writings from the 17th century. According to the author, this separation may have hindered the development of disciplines such as neuropsychology and psychosomatics for several centuries. Careful reading of Descartes' work does not confirm these assertions and even provides contradictory evidence. Contrary to Damasio's assertion, Descartes locates pain as “a perception that refers us back to our body”. Throughout his work, he confirms his belief in an intricate mind-body relationship, as indicated by such remarks as: “… Indeed, all these feelings of hunger, thirst, pain, etc., are nothing more than certain confused ways of thinking that originate in, and depend upon the union and, what appears to be an intermingling of the mind with the body”. In a similar fashion, in his treatise on Passions of the Soul, Descartes devotes several chapters to what is presently referred to as psychosomatics. He even describes what is currently known as breath holding spells (white form) in the infant, under the following title: Why some Children turn pale instead of crying? Descartes' followers pursued their research in the same direction. In the same vein, Nicolas Malebranche studied “Of the link between ideas from the mind and traces from in brain”, which completely fits our current definition of neuropsychology, with of course a chapter devoted to the subject “Of memory”. He goes as far as suspecting the existence of the nerve impulse by differentiating it from its anatomical basis and shows an interest in “The communication which exists between the mother's brain and the child's”. The reasons for such a misunderstanding of Cartesian thinking probably reside in the confusion Damasio makes between two terms, mind and soul, which he uses interchangeably, whereas Descartes viewed them as very discrete entities. The first term relates by its very nature to brain functioning and is relevant to neurosciences, while the second term, which is radically distinct from the substratum, allows one to exert the free choices of human thinking, as emphasized by Socrates in Platon's Phedon (or about the soul). The same confusion is responsible for Damasio's interpretation of the famous “I think, therefore I am” in the Discours de la méthode (Discourse on method) as an assertion of the existence of thought outside of any organic support, which is not what Descartes meant. Through this assertion, Descartes was trying to extract knowledge from the irrational world to which it had belonged up until then, and to anchor it into rational evidence and logical reasoning. This is what scientists are still trying to do today. It is therefore clear that nothing in Descartes' work goes against the principles of modern neuropsychology; in fact it is quite the opposite. It remains to be seen whether the confusion between mind and soul is of little importance, outside of a few polemists like us, or whether it raises the issue of the limits of the field of investigation of neuropsychological sciences. Can our thinking be reduced to cognitive activities or can these favor the expression of something else?