Our book today is the new one from Jerome Kagan, the emeritus professor of psychology at Harvard University. The book is On Being Human: Why Mind Matters (a pleasingly sturdy hardcover from Yale University Press), consisting of a series of connected meditations on topics ranging from the power of societal norms to the suggestive effects of education to the nature of the human psyche – all rich, fat topics here examined in an easy, erudite prose that strikes a near-perfect balance between formal essay and personal conversation. When Kagan writes that his essays are “best read in the evening, preferably over a glass of wine,” he’s not being smarmy; these pieces really do feel like “the reflections of a retired academic psychologist who has morphed into a well-fed stowaway admiring the talented crew solving problems he could not have imagined in the summer of 1954 when he left New Haven with his pregnant wife to take his first faculty position at Ohio State University.”

The book will provide a feast of ideas for the challenge-hungry reader, but some of the bits are more easily palatable than others. The crux of the book, in fact, is downright indigestible.

Over and over, Kagan returns to the concepts of mind and brain, of genetics and the intangible, of biological materialism and … well, what lies outside of biological materialism? Narnia?

He spends a good deal of time writing about thoughts. Not neurons firing, not electrolytes flashing, but something else, some combination that’s demonstrably more than the sum of its parts. Throughout On Being Human, Kagan contends that although medical science understands the workings of the human brain better than ever, the human mind remains a mystery that cannot be scientifically quantified:

An understanding of the feelings and thoughts evoked by listening to Beethoven’s Ninth Symphony in a quiet room on a winter night, seeing the torture of a prisoner on a television screen, or walking in an autumn forest when the foliage is at peak color requires evidence that a brain cannot provide and sentences that are inappropriate for neurons and circuits.

He looks at several series of experiments done to prove both a reinforcement and a disconnect of the thoughts in a human brain and the corresponding responses in a human body – including the famous placebo effect, in which a patient’s belief that he’s been given effective medicine can often produce physical results roughly analogous to what the actual medicine would have produced. In Kagan’s view, this powerfully intuitive phenomenon clinches that idea that we are minds inhabiting brains rather than brains manufacturing minds:

If Western scientists had not decided that material substances were the foundations of all events, there would have been no need to invent the word placebo. This term is needed to explain why immaterial thoughts can have beneficial consequences on the body or mood. Only those who believe that the water they are drinking has a sacred power benefit from drinking it.

But of course thoughts aren’t immaterial. They arise entirely out of specific physical, chemical processes (dead people don’t have thoughts; noses don’t have thoughts; kidney stones don’t have thoughts). It’s no more mysterious that “immaterial” thoughts could temporarily produce a placebo improvement in a sick person than it is that “immaterial” thoughts could make an athlete train hard and run a marathon.

“The neuroscientist’s distrust of the invisible, immaterial processes,” Kagan writes, “makes it easy to regard thoughts as epiphenomena that one day will be explained and understood as derivatives of the brain.” This is almost exactly right. Neuroscientists – indeed, all scientists – distrust the immaterial because nothing immaterial has ever been demonstrated to exist. Scientists distrust the idea of the immaterial because the immaterial is surpra-natural and therefore supernatural, and rational inquiry has been exposing and shrinking the supernatural for five hundred years without ever encountering a verifiable obstacle. There is absolutely no logical reason to think that process won’t continue. That process is continuing, in laboratories all over the world, every day. On Being Human thinks it’s an inquiry into the fundamental limits of neuroscience, but it isn’t. It’s actually just a progress report – and an inadvertently promising one at that. In less than a hundred years, in less than fifty years, Hell, some first-year med student might be having a crucial insight right now, there will be sentences completely appropriate for neurons and circuits. And they won’t make Beethoven’s Ninth in a quiet room on a winter’s night one single bit less moving.