Freedom Evolves. Daniel C. Dennett. xvi + 347 pp. Viking, 2003. $24.95.
Science has always had things to say about human nature, and now more than ever. The shelves of bookshops groan with offerings that show how everything we think about ourselves is being transformed by "revolutionary developments in molecular biology, genetic engineering, nanotechnology, artificial intelligence, artificial life, chaos theory, massive parallelism, neural nets, the inflationary universe, fractals, complex adaptive systems, linguistics, superstrings, biodiversity, the human genome, expert systems, punctuated equilibrium, cellular automata, fuzzy logic, virtual reality, cyberspace, and teraflop machines. Among others." The list comes from an article by literary agent John Brockman on the upmarket scientific Web site Edge (www.edge.org). Out go fuddy-duddy Shakespeare and Proust, Aristotle and Mill, and in comes a chorus of scientific cheerleaders who believe they have all the answers to life, human nature and everything. But curiously absent are the voices of historians, anthropologists and most psychologists, whose empirical disciplines surely have some claim to tell us more than a bit about human nature.
The public may like the triumphal note of these books, but it has fewer critical weapons at its disposal than some of us might wish. Thank heavens, then, for Daniel Dennett, a distinguished philosopher with an insatiable appetite for science and especially for the places where science needs interpretation. Scientists and philosophers need one another, he observes: Philosophers need to know the relevant scientific facts, and scientists need to know the history of philosophy. As Dennett says in commenting on Brockman's article, "Scientists who think their up-to-date scientific knowledge renders them immune to the illusions that lured Aristotle and Hume and Kant and the others into . . . difficulties are in for a rude awakening." Among the topics that show the need for interpretation are consciousness (with its curious habit of eluding science) and free will. As Leibniz remarked three centuries ago, if you could blow the brain up to the size of a mill and walk about inside, you would not find consciousness. Nor would you discover the spark of human agency. You would only observe the countless events that take place in the billions of neurons and the pathways between them, each event obeying inexorable physical laws. This might lead the unwary to deny that either consciousness or free will exists, and it takes a lot of philosophical sophistication to realize that those who have attempted to unearth the roots of consciousness in this way were digging in the wrong place, or in the right place with the wrong tools. Perhaps free will can be seen more plainly in a child skipping down the street than in the teeming cellular activity in his or her brain.
A good illustration of why the scientist needs the philosopher can be found in Dennett's new book, Freedom Evolves, in a fine discussion of the experimental data of Benjamin Libet (now professor emeritus of physiology at University of California, Davis), which show that the neural activity that begins an action starts up around a third of a second before the agent's conscious decision to act. Neuroscientists have frequently interpreted this as showing that decisions are somehow illusions: Consciousness is "out of the loop." They maintain that the action is originally precipitated in some part of the brain, and off fly the signals to muscles, pausing en route to tell you, the conscious agent, what is going on (but like all good officials letting you, the bumbling president, maintain the illusion that you started it all).
Dennett excels at revealing the philosophical mistakes at work here. He shows the fallacy in supposing that the will, if it exists at all, would have to be a kind of intervention from the spirit-world, taking place behind and before physical activity. As he points out, most philosophers abandoned that conception of free will ages ago, in favor of a picture in which agency comes with ongoing control and ongoing responsiveness to reason, or other cognitive activity. This substitutes a "compatibilist" picture of free will for the discredited dualistic or "interventionist" conception. But, lo and behold, neurologists are still using the latter to interpret their data.
In the more sophisticated compatibilist picture, there need be no single "moment" of decision. A decision is something that you, the whole person, make, and there is no reason why it should not be smeared out over time just as it is over space. When a legislature makes a decision, things may happen in widely spaced committee rooms at widely spaced intervals. U.S. Senator Huey Long, "The Kingfish," was shot on a Sunday evening in the capitol building in Baton Rouge and died a day and a half later in the hospital. Thinking that there must be one moment of decision at one place from which events flow outward in the brain is like thinking that there must be one location and time for Long's murder.
When people who subscribe to the interventionist conception of free will are told how decisively evolution and culture shape them, it seems to them to imply that everything, including their values, is "engineered," and that this, if true, would take away their responsibility and turn them into robots. But the freedom they want, and think is being threatened, is nothing more than a fantasy. What the philosopher can give them is what they ought to want: an understanding of themselves as cognitively complex, capable of informed and well-shaped responses to reason. Evolution and culture, far from imprisoning us, have put us on a pedestal, from which we can see farther than any other animal. But people are loath to relinquish the dream of independence from everything natural, the fantasy of standing over and above physical nature and telling our brains how to behave. And our beliefs about these matters have political implications: Many of the battles between right and left are fought over conceptions of responsibility and free will that are to varying degrees fantastical.
One role for the philosopher is that of cautious critic or skeptic, but another is that of ideologue or cheerleader. Dennett is very unusual in playing both roles. He is able to criticize misconceptions as well as anyone and also has a boyish enthusiasm for the tools that science makes available. Although he has visited much of the territory of this work before, in books such as Consciousness Explained and Elbow Room, here he promises to integrate his views of consciousness and freedom with his other great scientific interest, evolutionary theory. I share his enthusiasm for science, although sometimes I found myself veering toward the critical, particularly when the controversial notion of a "meme" reared its head. The question is whether it is insightful or fanciful to compare cultural items like literacy or cooking recipes to the building blocks of evolution, self-replicating genes. If this is an insight, then it may be pretty literally true that a cook is a recipe's way of making another recipe. Dennett enjoys the idea; I join the doubters, but this is not an issue to be settled in a sentence or two.
Dennett is a marvelously vivid writer in total command of his argument. He is infectiously enthusiastic about the subject and the fields of knowledge that help us to examine it. Dennett is far better than almost anybody else on such hackneyed, and often ill-posed, issues as nature versus nurture. He is a perfect example of the philosopher coming out of the somewhat airless and cramped closet that is graduate school, but without abandoning the delicacy of touch and the care with ideas that such an education enforces. His book is not entirely easy, but it is never harder than the material demands. Anyone interested in the interaction between scientific theory and the way we should think about human nature could do no better than to read it.