Part I: Starting in the Middle "Starting in the Middle", Part I of ''Darwin's Dangerous Idea'', gets its name from a quote by
Willard Van Orman Quine: "Analyze theory-building how we will, we all must start in the middle. Our conceptual firsts are middle-sized, middle-distance objects, and our introduction to them and to everything comes midway in the cultural evolution of the race." The first chapter "Tell Me Why" is named after a song. Before
Charles Darwin, and still today, a majority of people see
God as the
ultimate cause of all design, or the ultimate answer to 'why?' questions.
John Locke argued for the primacy of
mind before
matter, and
David Hume, while exposing problems with Locke's view, could not see any alternative. s as an analogy. Darwin provided just such an alternative:
evolution. Besides providing
evidence of common descent, he introduced a
mechanism to explain it:
natural selection. According to Dennett, natural selection is a mindless, mechanical and
algorithmic process—Darwin's dangerous idea. The third chapter introduces the concept of "skyhooks" and "cranes" (see below). He suggests that resistance to
Darwinism is based on a desire for skyhooks, which do not really exist. According to Dennett, good
reductionists explain apparent
design without skyhooks;
greedy reductionists try to explain it without cranes. Chapter 4 looks at the tree of life, such as how it can be visualized and some crucial events in life's history. The next chapter concerns the possible and the actual, using the 'Library of
Mendel' (the space of all
logically possible genomes) as a conceptual aid. In the last chapter of part I, Dennett treats human
artifacts and
culture as a branch of a unified Design Space.
Descent or
homology can be detected by shared design features that would be unlikely to appear independently. However, there are also "Forced Moves" or "Good Tricks" that will be discovered repeatedly, either by natural selection (see
convergent evolution) or human investigation.
Part II: Darwinian Thinking in Biology '' The first chapter of part II, "Darwinian Thinking in Biology", asserts that
life originated without any skyhooks, and the orderly world we know is the result of a blind and undirected shuffle through chaos. The eighth chapter's message is conveyed by its title, "Biology is Engineering";
biology is the study of design,
function, construction and operation. However, there are some important differences between biology and
engineering. Related to the engineering concept of optimization, the next chapter deals with
adaptationism, which Dennett endorses, calling
Gould and
Lewontin's "refutation" of it an illusion. Dennett thinks adaptationism is, in fact, the best way of uncovering constraints. The tenth chapter, entitled "
Bully for Brontosaurus", is an extended
critique of
Stephen Jay Gould, who Dennett feels has created a distorted view of evolution with his
popular writings; his "self-styled revolutions" against adaptationism,
gradualism and other orthodox Darwinism all being false alarms. The final chapter of part II dismisses
directed mutation, the
inheritance of acquired traits and
Teilhard's "
Omega Point", and insists that other controversies and hypotheses (like the
unit of selection and
Panspermia) have no dire consequences for orthodox Darwinism.
Part III: Mind, Meaning, Mathematics and Morality '', which appears at the beginning of chapter 16 "On the Origin of Morality". "Mind, Meaning, Mathematics and Morality" is the name of Part III, which begins with a quote from Nietzsche. Chapter 12, "The Cranes of Culture", discusses
cultural evolution. It asserts that the
meme has a role to play in our understanding of culture, and that it allows
humans, alone among
animals, to "transcend" our
selfish genes. "Losing Our Minds to Darwin" follows, a chapter about the evolution of brains, minds and
language. Dennett criticizes
Noam Chomsky's perceived resistance to the
evolution of language, its modeling by
artificial intelligence, and
reverse engineering. The evolution of meaning is then discussed, and Dennett uses a series of
thought experiments to persuade the reader that meaning is the product of meaningless, algorithmic processes. 's chess automaton, discussed in chapter 15. Chapter 15 asserts that
Gödel's Theorem does not make certain sorts of
artificial intelligence impossible. Dennett extends his criticism to
Roger Penrose. The subject then moves on to the
origin and evolution of morality, beginning with
Thomas Hobbes (who Dennett calls "the first
sociobiologist") and
Friedrich Nietzsche. He concludes that only an evolutionary analysis of
ethics makes sense, though he cautions against some varieties of 'greedy ethical reductionism'. Before moving to the next chapter, he discusses some
sociobiology controversies. The penultimate chapter, entitled "Redesigning Morality", begins by asking if ethics can be 'naturalized'. Dennett does not believe there is much hope of discovering an algorithm for doing the right thing, but expresses optimism in our ability to design and redesign our approach to moral problems. In "The Future of an Idea", the book's last chapter, Dennett praises
biodiversity, including
cultural diversity. In closing, he uses
Beauty and the Beast as an analogy; although Darwin's idea may seem dangerous, it is actually quite beautiful. == Central concepts ==