Darwin’s Dangerous Idea
The study of Darwinian theory has attracted many of the brightest minds and best writers of the late twentieth century. Because of fundamental philosophic and religious implications, the theory of evolution has become a battlefield for scholars and amateurs in a wide range of disciplines as diverse as ethics, paleontology, linguisics, and theology. In Darwin’s Dangerous Idea: Evolution and the Meanings of Life, Daniel C. Dennett attempts to integrate this enormously diverse research into a coherent but popularly understandable defense of neo-Darwinian thought. Charles Darwin’s “dangerous idea” is clearly held forth and reiterated throughout the book—that all products of evolutionary change, from orchid shape to human intelligence, are manufactured at the algorithmic level. “No matter how impressive the products of an algorithm,” he writes, “the underlying process always consists of nothing but a set of individually mindless steps succeeding each other without the help of any intelligent supervision.”
Dennett employs several strategies in presenting his carefully constructed argument. For one, he writes in an amusing and unaffected manner. Though he deals with many abstruse topics, he is never boring. As he notes in his preface, it is possible to fashion rigorous, watertight philosophical arguments that are nevertheless ignored by everyone outside the discipline. Thus in seeking to get “thinkers in other disciplines to take evolutionary thinking seriously,” he makes no apologies for telling a story. “I know you won’t be swayed by a formal argument,” he reasons, “. . . so I start where I have to start.”
Dennett leads the reader forward by analogy, often to some work in the humanities. If few people know much about the laws of astronomical probability, for example, many know something about Moby Dick (1851) and the potential importance of a single misplaced character: “Call me, Ishmael.” In considering the almost infinite varieties of Moby Dick that might have been possible with one, two, ten, or one hundred typographical errors per page (yet each version recognizable as Moby Dick), one begins to sense the vast opportunities of biological possibility during the five- billion-year course of evolution.
On the whole, Dennett succeeds admirably in humanizing his theory of algorithmic evolution. Yet he recognizes the limitations in dealing with so plebeian a medium. In treating the case of Elaine Morgan, an amateur science writer who is the principal exponent of the controversial aquatic-ape theory, he notes that she has been “accused” of telling a good story—as if it were a crime. Dennett neither defends nor attacks her theory, which is irrelevant to his argument, but he uses her situation as a study in professional jealousy, suggesting that established scientists and philosophers, whose theories are equally speculative, will be inherently resistant to her evidence.
At the level of argument, Dennett has confronted the necessary multiplicity of factors by grouping them into three categories, each designed to build upon the previous one in the accumulation of suggestive studies in favor of mindless algorithmic evolution. Just as Darwin had hit on the Principle of Accumulation of Design to explain the scientific processes involved in evolution, Dennett employs the Prin- ciple of an Accumulation of Evidences to convince readers that Darwin was right. Because he knows that even a watertight philosophical argument will not win the day, he adopts an engineering approach, in which all the competing claims are evaluated and either incorporated into the pyramid of evidence or discarded. By the end of the book, the reader has been raised to a pinnacle above the cacophony, with a clear view of the evolutionary landscape.
In part 1, Dennett again follows his hero in “Starting in the Middle.” Because Darwin had no concept of genes, DNA-based reproduction or other microdesign features of evolution, he was forced to begin with the plant and animal variations with which he and the scientific world were familiar, and then to work back from them. Dennett begins his argument by placing evolution within the familiar context of the pre-Darwinian philosophical ideas of Philo, John Locke, and David Hume, in which the human mind was given an independent and preeminent role in understanding the cosmos. After carefully defining the algorithmic process by which natural selection occurs, Dennett shows how this overturned previous philosophical viewpoints. Finally, he establishes a fundamental determinant in tracing the mindless, algorithmic process of evolution: “There is only one Design Space, and everything actual in it is united with everything else.” Though Darwin did not quite realize that he had said this, Dennett gives him credit for the discovery. Indeed, this leads Dennett to lay his “cards on the table,” confessing that Darwin deserves the award for the...
(The entire section is 2035 words.)