Descartes' Error: Emotion, Reason, and the Human Brain

The case studies of sensory agnosia were very interesting, especially the one where the patient had apparently lost the functioning of the part of his brain that stored the awareness of one side of the patient's body, to the point where the patient had no awareness or perception of that half at all, and even denied that he even had a problem with it. There can be no clearer demonstration of the fact that our consciousness and awareness depends entirely on that 3-pound, convoluted mass of nerve cells we call the brain.

As someone with a pretty fair background in the area myself (I did a master's and almost completed a Ph.D. in psychobiology) I can vouch for Damasio's command of the scientific and technical issues and details (notwithstanding that fact that Damasio is both an M.D. and a Ph.D.) so he has a good command of the medical issues also. The book is very well written, although not easy, but Damasio does a fine job of explaining the more difficult ideas.

One further comment, I read one review that was critical of Damasio for supposedly misinterpreting Descartes's dictum, "I think, therefore I am," and then spent the whole review discussing Descartes instead of Damasio's book. The reviewer also stated that because of this Damasio lacks scientific objectivity. Since his comment is itself a good starting point for discussing the most important aspect of Damasio's book, I thought I'd write a little more on it here.

Whether or not Damasio's interpretation of Descartes dictum is wrong or not, (and from the other reviewer's disjointed discussion, that itself isn't very clear), this is a minor detail, since Damasio simply uses this as a point of departure and from there on the vast majority of the book is devoted to a discussion of the neurological and brain issues, not to the technical details of the philosophy of mind-body dualism, for which there are already plenty of other discussions out there (having read many of them myself).

However one should precisely interpret Descartes's famous statement, Damasio is completely correct in pointing out the most important aspect of Descartes's idea--that the mind is fundamentally different from the brain itself and that one needs a dualistic theory to explain the separation of the apparently immaterial mind from the more material body--is wrong.

Although echoes of this theory can still be seen in modern philosophy, and were an important influence on idealist philosophers that followed Descartes, such as Kant, and even continue to have an influence on modern neo-Kantian theory and other thinkers, the advance of modern neurobiology has shown that these theories are fundamentally wrong.

Since we're on the subject--and to be completely fair--I will that say that one aspect of Kant's theory is quite accurate--that the mind is actively involved in organizing the data of the senses--and that ideas about the external world could not exist unless there were corresponding mental capabilities and constucts to match. Our understanding of sensory information processing and of advanced cortical abilities certainly show that the brain has evolved in a way that reflects the need for specific capabilities to enhance our survival in a dangerous world. Kant's idea that there are inborn mental faculties that allow us to form ideas about the external world isn't so different from this idea, and in that sense, Kant was right. (This would have been a good point for the other reviewer to make, but he got lost in the trivial details, and failed to see "the forest for the trees" (as he himself incorrectly said of Damasio)).

Anyway, returning to Damasio's book, this is well-written book on a fascinating aspect of modern neurobiology, and which has profound implications for western philosophies of idealism and dualism. Although not an easy book for the non-specialist, it's worth the effort.

I have one final suggestion to make, and that is you might want to read Michael Gazzaniga's more general introduction to neurobiology: "Nature's Mind: The Biological Roots of Thinking, Emotions, Sexuality, Language, and Intelligence," before tackling this one. It's also an excellent book and you'll have a more well-rounded understanding of the brain field which should stand you in good stead to tackle this book, or any other brain-oriented books, after reading it.


Some hints for enjoying this book more   December 25, 2003
Brad4d (United States)
13 out of 13 found this review helpful

Other reviewers have surely summarized and analyzed this fine book far better than I could, so here are some hints that may help you productively enjoy it:
1.) scan sections of the book before and after you read them. The author's simple expositions are terrific but the organization and data blending can be confusing, and the pace of such a book often slows uncomfortably. 2.) If you are new to this subject (and any non-professional who hasn't had a CNS course recently is probably a beginner) I'd supplement this book with a good but lighter introduction to brain research (I'd strongly recommend the NYT Book of the Brain). 3.) I'd advise using a good neuroanatomy text or atlas like Barr or Hanaway. The author's maps are surprisingly skimpy and I strongly hope he includes a few pages of neuroanatomical diagrams in any future editions. 4.) You may want to underline terms and definitions, and note the reference at the back of the book -- the book has no glossary and the index is annoyingly weak. 5.) I thought the most valuable sections were on the Somatic Marker Hypothesis, the Body-Minded Brain, and the Postscriptum -- consider scanning these sections first.
Good luck and enjoy. The author's credentials are superb, his perspective complements other authors such as Edelmann and LeDoux, and he brings the unique and empathetic perspective of a neurologist who has specialied in analyzing the changes associated wtih discrete neuropathological conditions. The ideas you may receive from this wonderful book should be well worth the effort, and you should gain some insight into the miracle of how we think/feel/are.


Challenging an old idea   March 3, 2003
Stephen A. Haines (Ottawa, Ontario Canada)
22 out of 25 found this review helpful

A "negative" title such as this carries unfortunate implications. The "error" must be identified, then explained and refuted. For newcomers to cognitive studies, Descartes "error" might seem an obscurity . Yet it has been the basic tenet of education and social thinking in the Western world for three centuries. "Cogito ergo sum" was translated into the belief that the mind and the remainder of the body were separate entities. Behaviour was controlled by the mind, while the body went about its own business. Damasio demolishes that long-standing mistake for good in this superbly written groundbreaking study.

The first indication of the relationship of the mind and body was the bizarre penetration of a railway worker's skull in 1848. The worker lived, but the damage to his brain left him with severe personality changes. The case opened the door to research leading to mapping areas of the brain that reflected various personality traits. Damasio recounts the incident, matching it with numerous clinical studies of his own. Additional work, some of it strongly innovative led Damasio and his colleagues to a reformulation of how the mind and body interact.

He reminds us that the brain is much more than a collection of electrically interacting cells. The body is sending information to the brain almost continuously, with the brain replying or initiating communication. These signals are both electrical and chemical. More importantly, Damasio reflects on the evolutionary origins of these conditions. For him, it is inevitable that the mind and body interact intimately. His proposed appellation for Emotions aren't separated from our reasoning processes, but are an integral part of them. The attempts by parents and educators to "train out" emotions in children are thus doomed to fail.

Damasio's thesis hinges on what he calls "somatic markers." The markers are areas of the brain which continuously interact with the body, particularly those areas we associate with emotions. If confronted with emotionally charged choices, the stomach "knots," the face may "flush" warmly, and perspiration may increase markedly. These body/brain functions begin developing early in the embryo. Indeed, they have a long evolutionary history, which firmly establishes their roots. In humans, the brain not only controls/reacts with the body in addressing stressful circumstances, but retains some level of memory of the events causing the reactions. Hence, even thinking about such circumstances can lead to bodily reactions associated with them. You need not be confronting an emotional situation to be able to express the feelings associated with it. This, of course, is most notably seen in actors or other performers. Damasio offers the excellent example of orchestra conductor Herbert von Karajan, whose pulse rate was higher while conducting than when confronted with an emergency situation in an airplane. To Damasio, "Descartes' error" was that he placed all these controls in a central location of the "mind" where, in fact, they are scattered over much of the brain.

The implications from this book will be far reaching. Besides impacting academic courses on behaviour, there will be changes in how we parent, how we deal with education, and even in the realm of law. Binding reason and emotion will revise uncountable long-standing ideas about how the mind deals with our surroundings. It is a work addressing fundamental questions about what make us human. Read it with care, aware that many preconceptions are likely to be challenged. The rewards for this effort will be great in years to come. [stephen a. haines - Ottawa, Canada]


CLASSIC!   March 9, 2008
Alexander Kemestrios Ben (Allendale, Mi. USA)
9 out of 9 found this review helpful

This book is already a classic of its kind. Yes, the hypotheses are not new, and yes, there is some speculation. So what?!

Damasio takes the abstruse and technically demanding field of neuroscience and turns it into a novel. The book is not dumbed down, nor is it patronizing.

Damasio's main contention is that logic and reason are impossible without emotion. That is why intuitions are called gut feelings. He goes over many case studies, experiments, and introspection, to drive this point home.

Our body is where the action takes place. Only after (or sometimes concurrent with) the body makes up its mind, does the mind follow. For a quick example, suppose you are sitting down in a college classroom. There is an open seat next to you. Suddenly, you spot a voluptuously delightful young lady walking toward you. What happens to you? Your heart starts to beat faster, your palms sweat a little, your body tenses up; and neurotransmitters release a cascade of chemicals into your blood stream which modulate your body's internal viscera. You focus your attention on this women. Do you invite her to sit next to you? Or, are you to nervous to do so? If you are too nervous, think about what is going on. Is it because your brain is telling you that you are? No. Your body is sending signals to your brain and vice versa in a feedback loop. Your brain then 'reads' the signals comming from your body as nervousness. Without a body, you could 'feel' nothing. There would be no emotion.
Thus, to a large degree, your decision was made prior to conscious awareness, and you could not control it.

This way of thinking seems anathema to Westerners who love to believe that rationality means pure logic without emotion. You know what happens to decision making when your emotions become blunted due to brain damage? It goes completely out the window.

As Damasio says: "No body, never mind."

I think the take home message of this book is that we are biological organisms through and through. There is no Cartesian soul: Nothing that makes humans unique machines of deduction. We are at the mercy of our passions.

This should not be surprising. Great thinkers from Augustine to Hume have suspected as much. Now we have the science to confirm such insights.

N.B. some of the material in this book is dated. Consult Damasio's later books and Journal articles by Ledoux, Damasio et al. For the latest progress in neuroscience.


Don't Read Damasio 'Less You're Interested in Cerebating   January 7, 2005
Edgar Foster (United States)
14 out of 17 found this review helpful

What one thinks of Damasio's lovely work, _Descartes' Error_, will largely depend on how interested one is in matters pertaining to the human brain, consciousness and the self. Additionally, one who does not have much of an appetite for technical language will probably not get very fair in this work. Much of Damasio's study is also hypothetical in nature. Therefore, I would not recommend this work to those who have little to no tolerance for abstracta or theoria. But if you are intensely intrigued by the inner workings of the human brain, this book is for you. Damasio initiates his discussion with a fascinating story about Phineas Gage, a man who had a 3 1/2 foot iron rod pass through his head and lived to tell about it. Damasio moves from Gage to other patients who have experienced damage to their frontal lobes and reviews the effect it had on their lives. He argues that reason and emotions are both needed in order for sound judgment or prudence to obtain. Finally, Damasio challenges Cartesian dualism, which posits the anthropological notion of a RES EXTENSA and RES COGITANS. Damasio winds up contending that the "self" which has received so much theoretical attention throughout human history is no doubt neural in nature, unlike Descrates envisioned it. In short, there is no self without a functioning brain in a body. At least, not on this earth. The one drawback that I find with this book is that Damasio does not spend enough time critiquing Cartesian dualism. Nevertheless, the journey that terminates in an analysis of Cartesianism is well worth the ride. Moreover, the author offers an alternative to Descartes' theory that is both compelling and thought-provoking.