Of the tremendous scientific revolutions in the past hundred years, in understanding the physical structure of reality, the genetic basis of humanity, and the history of the universe, understanding how the mind rules us is only now coming to the fore. Dr. Antonio Damasio, Professor and head of the department of neurology at the University of Iowa Medical Center, has published the third in his series of books that attempts to popularize key parts of that breakthrough. Looking for Spinoza continues his exposition of the overwhelming role of emotion in life and, exploiting the intuitive understandings of the seventeenth-century philosopher named in the title, hypothesizes how biology might link to ethics and a desirable lifestyle. Although that latter expansion seems a contrived and wooly digression, the first half of the book is a summary of such important findings that this reviewer highly recommends its study.

Ever since Descartes, the “mind/body problem” has puzzled intellectuals. The brain, of course, is part of the body, but the mind, which can perform introspection, was considered something non-physical and, for many, persists after death as the soul. Modern neurology has demonstrated that the mind is, instead, “a process” of the body, that the brain draws on signals from the body through the nervous system and the bloodstream to create a self whose main motivation is preservation. The brain constructs neural maps of every body part, down to the cells, and develops its “feelings” as a result of its self-regard. There’s back chatter, of course—the brain manages its body’s life both autonomously and consciously.

All this has fundamental derivatives. First, the brain would be lost without its body. Damasio notes that patients without inputs lose complete consciousness. Secondly, emotions derive from this interrelationship and form will. The computer, without the interplay of body and brain-determined drives created by eons of evolution, will only be able to follow engineered rules. Contrary to some science fiction, it will never be an analogue of the mind. And, despite the triumph of reductionism in this explanation of the mind, the immense chorus of influences both mental and physical will continue to make determined thoughts and acts unpredictable.

Damasio supports his thesis with a lot of evidence, but little proof. He shows us corroborative examples using brain-damaged patients and MRI scans but, due to the nature of the enquiry, cannot show us empirical experiments that limit variables. Still, he and his quoted peers are very believable. As time passes, their understandings will add to the secularization of intellectuals as well as “…allow biomedical science to develop effective treatments for pain and depression…”

The scientific discussion is quite lucid, although not as taut as this reviewer would like, while the flow sometimes stutters by the insertion of Latin names for parts of the brain. As noted, the latter part of the book dabbles with Spinoza’s biography and the author’s philosophy of life. The book is hard reading in spots, but well worth the struggle.