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

Descartes' philosophical perspectives have exerted tremendous influence on science and medicine for more than three hundred years. As scientific knowledge progressed, some of his theories, such as his conviction that fine particles in the blood distill into "animal spirits," have been empirically contradicted. But, his most famous dictum, "I think, therefore I am," still wields considerable influence. In their companion volume to the latest revision of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Maxmen and Ward maintain that symptoms can emerge and affect both the mind and the brain; thus Cartesian dualism continues into 1995. This dualism, Descartes' "man the machine metaphor" and the computer model used to describe the human brain, dominate medicine and scientific research.

In his book, Descartes' Error: Emotion, Reason, and the Human Brain, Antonio Damasio strives to overturn Descartes' theory by tackling three difficult questions: how, if at all, does emotion influence decision-making processes; where, in the human brain, does reasoning originate; and, how do the brain and the body interact to create the "world" uniquely experienced by each of us.

Damasio uses Phineas Gage's accident as a starting point. As a result of a blasting accident, Phineas Gage suffered significant brain damage in the Summer of 1848. An iron rod pierced his left cheek, entered the base of his skull and proceeded to exit through his frontal lobe. Surprisingly, Gage remained conscious and intelligently answered his doctor's questions. But Gage changed. From a quiet, well-respected man, Gage became irreverent and irresponsible. He would start projects but never finish them. His ability to plan for the future, conduct his life according to social rules, and act advantageously no longer existed. Then, from his own patients' experiences with emotion and reasoning, Damasio demonstrates that similar lesions have similar outcomes. This kind of damage to the frontal lobe impaired his patients' emotional capacity and subsequently their logical abilities.

Readers familiar with general semantics will appreciate Damasio's thesis for several reasons, especially its rejection of Cartesian dualism. His thesis will also remind them of the mind-body example frequently used by writers to illustrate the extensional device of the hyphen. Damasio explicates the neural mechanisms that permit semantic reactions to take place. He illuminates the interaction of the environment, socialization, and behavior, and by doing so brings contemporary scientific support to some general-semantics premises. Consider Damasio's statement: "Perhaps the most indispensable thing we can do as human beings, every day of our lives, is remind ourselves and others of our complexity, fragility, finiteness and uniqueness." (Page 252.) And, readers will recognize the Aristotelian logic embedded in Descartes' dualistic postulates.

Damasio's book stands on its own merits and does not need parallel treatises to bolster it. Nevertheless, readers with a background in general semantics will enjoy developing these harmoniously intertwined themes as they read Damasio's intriguing book.

Damasio's work raises some interesting "follow-up" research questions such as: do frontal lesions impact on "free-will"?; do repressed memories have proven neurological correlates?; and does pre-verbal memory exist?

Damasio's elegant linking of feelings and emotions to reason and adaptive social behavior opens new vistas for social and scientific research. Readers with little or no knowledge of neuroscience need not feel intimidated by Damasio's text. His style and his liberal use of diagrams make the subject clear and understandable. Those readers with neuroscience in their background will enjoy his trailblazing synthesizations and his thought-provoking assertions.

Maxine S. Theodoulou, Ph.D. Bronx, New York