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Authors: Daniel C. Dennett

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by the curious similarity between his arguments and those of the philologists Where might this be from?

studying the genealogy of languages (not, as in the case of the Plato scholars, the genealogy of specific texts). In
The Descent of Man
(1871, p. 59) he pointed explicitly to their shared use of the distinction between homologies and analogies that could be due to convergent evolution: "We find in distinct languages striking homologies due to community of descent, and analogies due to a similar process of formation."

Imperfections or errors are just special cases of the variety of marks that speak loudly—and intuitively—of a shared history. The role of chance in twisting the paths taken in a bit of design work can create the same effect FIGURE 6.1

without creating an error. A case in point: In 1988, Otto Neugebauer, the Before reading on, try it. You can probably figure it out even if you don't great historian of astronomy, was sent a photograph of a fragment of Greek really know how to read the old German
Fraktur
typeface—and even if you papyrus with a few numbers in a column on it. The sender, a classicist, had don't know German! Look again, closely. Did you get it? Impressive stunt!

no clue about the meaning of this bit of papyrus, and wondered if Neuge-Neugebauer may have his Babylonian column G, but you quickly deter-bauer had any ideas. The eighty-nine-year-old scholar recomputed the line-mined, didn't you, that this fragment must be part of a German translation of to-line differences between the numbers, found their maximum and minimum some lines from an Elizabethan tragedy
(Julius Caesar,
act III, scene ii, lines limits, and determined that this papyrus had to be a translation of part of 79-80, to be exact). Once you think about it, you realize that it could hardly

"Column G" of a Babylonian cuneiform tablet on which was written a be anything else! The odds against
this
particular sequence of German letters'

Babylonian "System B" lunar ephemeris! (An ephemeris is, like the
Nautical
getting strung together under any other circumstances are Vast. Why? What
Almanac,
a tabular system for computing the location of a heavenly body for is the particularity that marks such a string of symbols?

every time in a particular period.) How
could
Neugebauer make this Sherlock Nicholas Humphrey (1987) makes the question vivid by posing a more Holmes-ian deduction? Elementary: what was written in Greek (a sequence drastic version, if you were forced to "consign to oblivion" one of the of sexagesimal—not decimal—numbers) was recognized by him to be part—

following masterpieces, which would you choose: Newton's
Principia,
column G!—of a highly accurate calculation of the moon's Chaucer's
Canterbury Tales,
Mozart's
Don Giovanni,
or Eiffel's Tower? "If the choice were forced," Humphrey answers,

I'd have litde doubt which it should be: the
Principia
would have to go.

How so? Because, of all those works, Newton's was the only one that was 4. Scholarship marches on. With the aid of computers, more recent researchers have shown "that the nineteenth-century model of the constitution and descent of our manu scripts of Plato was so oversimplified that it must be counted wrong. That model, in its original form, assumed that all the extant manuscripts were direct or indirect copies of 5. I am grateful to Noel Swerdlow, who told this story during die discussion following his one or more of the three oldest extant manuscripts, each a literal copy; variants in the talk "The Origin of Ptolemy's Planetary Theory," at the Tufts Philosophy Colloquium, more recent manuscripts were then to be explained either as scribal corruption or arbi October 1, 1993, and subsequently provided me with Neugebauer's paper and an expla-trary emendation, growing cumulatively with each new copy ___ " (Brumbaugh and Wells nation of its fine points.

1968, p. 2; the introduction provides a vivid picture of the fairly recent state of play.) 140 THREADS OF ACTUALITY IN DESIGN SPACE

The Unity of Design Space
141

replaceable.
Quite simply: if Newton had not written it, then someone else methods are cranes, which can be borrowed, with acknowledgment, and used would—probably within the space of a few years __ Tne
Principia
was a to do lifting in other parts of Design Space. In the extreme case, the crane glorious monument to human intellect, the Eiffel Tower was a relatively developed by a scientist may be of much more value than the particular minor feat of romantic engineering; yet the fact is that while Eiffel did it
his
lifting accomplished by it, the destination reached. For instance, a proof of a way, Newton merely did it God's way.

trivial result may nevertheless pioneer a new mathematical method of great value. Mathematicians put a high value on coming up with a simpler, more Newton and Leibniz famously quarreled over who got to the calculus first, elegant proof of something they have already proved—a more efficient and one can readily imagine Newton having another quarrel with a crane.

contemporary over who should get priority on discovering the laws of In this context, philosophy can be seen to lie about midway between science gravitation. But had Shakespeare never lived, for example, no one else would and the arts. Ludwig Wittgenstein famously stressed that in philosophy the ever have written his plays and poems. "C P. Snow, in the
Two Cultures,
process—the arguing and analyzing—is more important than the product—the extolled the great discoveries of science as 'scientific Shakespeare'. But in conclusions reached, the theories defended. Though this is hotly (and one way he was fundamentally mistaken. Shakespeare's plays were correctly, in my opinion) disputed by many philosophers who aspire to solve Shakespeare's plays and no one else's. Scientific discoveries, by contrast, real problems—and not just indulge in a sort of interminable logotherapy—

belong—ultimately—to no one in particular" (Humphrey 1987). Intuitively, even they would admit that we would never want to consign Descartes's the difference is the difference between discovery and creation, but we now famous "cogito ergo sum" thought experiment, for example, to oblivion, even have a better way of seeing it. On the one hand, there is design work that though none would accept its conclusions; it is just too nifty an intuition homes in on a best move or forced move which can be seen (in retrospect, at pump, even if all it pumps is falsehoods (Dennett 1984, p. 18). Why can't you least) to be a uniquely favored location in Design Space accessible from copyright a successful multiplication of two numbers? Because anyone could many starting points by many different paths; on the other hand, there is do it. It's a forced move. The same is true of any simple fact that a genius isn't design work the excellence of which is much more dependent on exploiting (

needed to discover. So how do the creators of tables or other routine (but and amplifying) the many contingencies of history that shape its trajectory, a labor-intensive) masses of printed data protect themselves from unscrupulous trajectory about which the bus company's slogan is an understatement: copiers? Sometimes they set traps. I am told, for instance, that the publishers getting there is much more than half the fun.

of
Who's Who
have dealt with the problem of competitors' simply stealing all We saw in chapter 2 that even the long-division algorithm can avail itself their hard-won facts and publishing their own biographical encyclopedias by of randomness or arbitrary idiosyncrasy—choose a digit at random (or your quietly inserting a few entirely bogus entries. You can be sure that if one of favorite digit) and check to see if it's the "right" one. But the actual idio-those shows up on a competitor's pages, it was no coincidence!

syncratic choices made as you go along cancel out, leaving no trace in the In the larger perspective of the whole Design Space, the crime of plagia-final answer, the right answer. Other algorithms can incorporate the random rism might be defined as
theft of crane.
Somebody or something has done choices into the structure of their final products. Think of a poetry-writing some design work, thereby creating something that is useful in further design algorithm—or a doggerel-writing algorithm, if you insist—that begins: work and therefore may have value to anyone or anything embarked on a

"Choose a noun at random from the dictionary ____ " Such a design process design project. In our world of culture, where the transmission of designs can produce something that is definitely under quality control—selection from agent to agent is enabled by many media of communication, the pressure—but which nevertheless bears the unmistakable signs of its par-acquisition of designs developed in other "shops" is a common event, almost ticular history of creation.

the defining mark of cultural evolution (which will be the topic of chapter Humphrey's contrast is sharp, but his vivid way of drawing it might 12). It has commonly been assumed by biologists that such transactions were mislead. Science, unlike the arts, is engaged in journeys—sometimes races—

impossible in the world of genetics ( until the dawn of genetic engineering).

with definite destinations: solutions to specific problems in Design Space.

You might say, in fact, that this has been the Official Dogma. Recent But scientists do care just as much as artists do about the routes taken, and discoveries suggest otherwise—though only time will tell; no Dogma ever hence would be appalled at the idea of discarding Newton's actual work and rolled over and died without a fight. For instance, Marilyn Houck (Houck et just saving his destination (which someone else would eventually have led us al. 1991.) has found evidence that, about forty years ago, in either Florida or Central America, a tiny mite that feeds on fruit flies happened to to in any case). They care about the actual trajectories because the methods used in them can often be used again, for other journeys; the good 142 THREADS OF ACTUALITY IN DESIGN SPACE

The Unity of Design Space
143

puncture the egg of a fly of the
Drosophila willistoni
species, and in the dependent not just on their authors' biological inheritance, but on the books process picked up some of that species' characteristic DNA, which it then that have come before them. This dependence is conditioned by coincidences inadvertently transmitted to the egg of a (wild)
Drosophila melanogaster
fly!

or accidents at every turning. Just look at my bibliography to discover the This could explain the sudden explosion in the wild of a particular DNA main lines of genealogy of this book. 1 have been reading and writing about element common in
D. willistoni
but previously unheard of in
D. melano-evolution since I was an undergraduate, but if I had not been encouraged by
gaster
populations. She might add: What else could explain it? It sure looks Doug Hofstadter in 1980 to read Dawkins'
The Selfish Gene,
I probably like species plagiarism.

would not have begun coalescing some of the interests and reading habits Other researchers are looking at other possible vehicles for speedy design that have been major shapers of this book. And if Hofstadter had not been travel in the world of natural (as opposed to artificial) genetics. If they find asked by
The New York Review of Books
to review my book
Brainstorms
them, they will be fascinating—but no doubt rare—exceptions to the (1978), he probably would never have hit upon the bright idea of proposing orthodox pattern: genetic transmission of design by chains of direct descent that we collaborate on a book,
The Mind's I
(1981), and then we would not only.6 We are inclined, as just noted, to contrast this feature sharply with have had the opportunity for mutual book-recommending that led me to what we find in the freewheeling world of cultural evolution, but even there Dawkins, and so forth. Even if I had read the same books and articles by we can detect a powerful dependence on the combination of luck and following other paths, in a different order, I would not be conditioned in copying.

exactly the same way by that reading, and hence would have been unlikely to Consider all the wonderful books in the Library of Babel that will never be have composed (and edited, and re-edited)
just
the string of symbols you are written, even though the process that could create each of them involves no now reading.

violation or abridgment of the laws of nature. Consider some book in the Can we measure this transmission of Design in culture? Are there units of cultural transmission analogous to the genes of biological evolution? Daw-Library of Babel that you yourself might love to write—and that only you kins (1976 ) has proposed that there are, and has given them a name:
memes.

could write—for instance, the poetically expressed autobiographical tale of Like genes, memes are supposed to be replicators, in a different medium, but your childhood that would bring tears and laughter to all readers. We know subject to much the same principles of evolution as genes. The idea that there that there are Vast numbers of books with just these features in the Library of might be a scientific theory, memetics, strongly parallel to genetics, strikes Babel, and each is composable in only a million keystrokes. At the daw-dling many thinkers as absurd, but at least a large part of their skepticism is based rate of five hundred strokes a day, the whole project shouldn't take you much on misunderstanding. This is a controversial idea, which will get careful longer than six years, with generous vacations. Well, what's stopping you?

consideration in chapter 12, but in the meantime we can set aside the You have fingers that work, and all the keys on your word-processor can be controversies and just use the term as a handy word for a salient (
mem-depressed independently.

orable) cultural item, something with enough Design to be worth saving—or Nothing is stopping you. That is, there
needn't
be any identifiable forces, stealing or replicating.

or laws of physics or biology or psychology, or salient disabilities brought on by identifiable circumstances (such as an ax embedded in your brain, or a gun pointed at you by a credible threatener). There are Vastly many books The Library of Mendel (or its

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