Descartes Error opens with a story that has surely gained a life of its own by now. The story of the most unfortunate Phineas Gage who sustained a horrific injury from a steel tamping rod passing through his brain. The story is compelling because, not only did Gage survive, but he seemed to survive without harm. He could walk, talk, think and all of the things you’d expect.
Except he wasn’t without harm. To steal the punchline, he sustained an injury that left him unable to function properly in society. Damasio hypothesizes, based on similar cases with similar injuries, that Gage lost his ability to connect emotion into reasoning, and ultimately lost his ability to make judgements about preferred future states.
This book is now over 20 years old, and it remains a classic in neuroscience. Its central hypothesis is the “somatic marker” hypothesis, which essentially states that reason is connected to embodied emotion. That decision making isn’t just rational and disembodied, but it is also connected deeply into feelings across the body.
These feelings, or somatic markers, enable certain options to be prioritised over others. Somatic markers are informed by the continual, day to day senses, decisions and consequences. The are, in this sense, emergent. They can be conscious or unconscious, but what they do is facilitate “rational” decision making in the complex world that makes up human society. So much so that, without them (as demonstrated by Damasio’s case studies), people are paralysed in their decision making.
Emotions are vital for rational thought. And that fact that this statement is relatively uncontroversial is sign of how significant this book has become. Its subject matter has led to a vast array of writing around the neuroscience of decision making, the self, and how to potentially overcome these embodied emotions. It has led to the recognition that the body and how it processes emotion is critical for how to enhance the performance of the mind, and similarly how the mind is vitally important for how the body functions.
A fascinating book that provides the baseline for so much of what is out in the marketplace of ideas around decision making and emotion. A book that is at times heavy reading, but is for the most part a ripping yarn that rearranges a number of pieces of the human puzzle to derive a compelling hypothesis for how we think.