Collage parisien, on the mind-body problem
30 August 2016
As I tread the roads of this majestic city, trying to leave all work behind, one topic keeps nagging at me, somewhere in the area where mind and the subconscious overlap. It is — quite appropriately, perhaps, in the labyrinth of history that is the Latin Quarter — the mind-body problem. Appropriately, not only because a lot of the philosophical debate around the subject has taken place in this area, along the years (although it was actually The Netherlands where both philosophers considered to have initiated the debate — Descartes and Spinoza — spent most of their lives); but also because, in a month or so, I am due to give a talk on this, at an interdisciplinary seminar for medical students and philosophers.
Contrary to general belief, Descartes’ view on the subject is not so much that the soul (or the mind) and the body are separate — as the generic phrase ‘mind-body dualism’ seems to suggest. Rather, he was interested in the unity between body and mind, which he addressed in his Passions of the Soul (written as a result of his correspondence with Princess Elizabeth of Bohemia, who kept probing him on the subject.) The connection between the two lies in the brain. Indeed, according to Descartes, some form of brain activity leads to particular states of mind, which he associates with passions or emotions. In other words, our thoughts arise from the core of our body; and it is these thoughts which lead to a certain moral behaviour. Take, for example, Descartes’ paragraph 94: “What we call ‘titillation’ or ‘pleasurable sensation’ occurs when the objects of the senses arouse some movement in the nerves, a movement that could harm the nerves if they didn’t have enough strength to resist it or if the body wasn’t in a healthy condition. This creates in the brain an impression that naturally testifies to the body’s healthy condition and strength; and so represents this to the soul as a good that belongs to it in its union with the body; and so this impression produces joy in the soul.” Likewise, “The sensation we call ‘pain’ always results from an action so violent that it injures the nerves. This sensation naturally signifies to the soul the bodily damage suffered from such an action, and the body’s feeble inability to withstand it, represents both as evils that are always unpleasant to the soul except when they cause some goods that the soul values more highly.”
This isn’t far from what mainstream contemporary neuroscience suggests — namely that it is the activity taking place in the brain, which affects our thinking and emotions. More specifically, the two hemispheres are responsible for different ways of thinking — the ‘left brain’ for the analytical and conceptual one; the right brain — for the intuitive, whilst the deeper layers of our cortex, which form our limbic system, are considered to be the “emotional brain”. So for instance, “when we experience feelings of sadness, joy, anger, frustration, or excitement, these are emotions that are generated by the cells of our limbic system”. These kinds of feelings (the equivalent of what Descartes calls “passions”) are different both from the tactile experience of feeling, which we owe to our sensory system of touch (located in the post central gyrus of the brain) and from the intuitive cognition we sometimes refer to as “gut feeling”, or a “higher cognition that is grounded in the right hemisphere of the cerebral cortex” (Jill Bolte Taylor, My Stroke of Insight, 2009, pp. 19-20).