Re: Ch. 6: Threads of Actuality in Design Space
Dennett has talked about design throughout the book, and in this chapter he zeroes in on it. Not being very familiar with the rest of the literature on evolution, I wonder whether Dennett is different in this regard--seeming to embrace the word that, after all, forms part of term that creationists came up with in an attempt to argue against evolution in a more sophisticated way. And it appears that at this point, anyway, Dennett doesn't quite rule out intelligence in the design work that has gone into each living thing--or does he? He can
rule out that evolution is not the kind of process that could have been wielded by an handicrafter God, such as the God of the Bible. But could intelligence, if not actually operating at the algorithmic level, be somehow dispersed throughout the process?
What evolution does is to add to the natural process of random genetic drifting that can be compared to "typographical change," a "lifting" that produces "an accumulation of design." Just by that gerund, "lifting," Dennett brings into play certain ideas of improvement, "rising,""progress," and telos
, and he knows that he does.
These intuitions about getting somewhere important, about design improvement,
about rising in Design Space, are powerful and familiar, but are
they reliable? Are they perhaps just a confusing legacy of the pre-Darwinian
vision of Design coming down from a Handicrafter God? What is the relationship
between the ideas of Design and Progress? There is no fixed agreement
among evolutionary theorists about this. Some biologists are fastidious,
going to great lengths to avoid allusions to design or function in their own
work, while others build their whole careers around the functional analysis of
this or that (an organ, patterns of food-gathering, reproductive "strategies,"
etc.). Some biologists think you can speak of design or function without
committing yourself to any dubious doctrine about progress. Others are not
so sure. Did Darwin deal a "death blow to Teleology," as Marx exclaimed, or
did he show how "the rational meaning" of the natural sciences was to be
empirically explained (as Marx went right on to exclaim), thereby making a
safe home in science for functional or teleological discussion?
On a related point, the "forced moves in design space" that seem to mean that certain basic living structures were arrived at out of necessity, I confess a diminished belief in the randomness of evolution. While I fully acknowledge that my
existence is an entirely random result of how my genome assembled at the very moment of conception--a moment that could have been influenced by what my father ate for lunch--I'm not so sure the same can be said for our species' existence. Sure, we arrived as a result of many linked contingencies, but there would have been millions of other possible contingencies that could have happened to produce an animal with something like our characteristics. I don't think that if one contingent event hadn't happened a half billion years ago, it would have been lights out for us. There are, as Dennett would put it, a Vast number of possible books in the library of Mendel. Shades of the anthropic principle.
The section on what we might expect aliens to look like underscores that there appear to be a certain determinism about design space. Aliens would have met the basic design criterion of having a self-contained metabolism bounded by a body. It also should not surprise us to encounter aliens who have developed locomotion and an enabling ability, vision. It might surprise us somewhat more to see a bilateral body layout, and a little more to see four appendages each with five digits. But it could be that the latter arrangement has very powerful benefits that life would find it hard to avoid--we don't know. It also is well within reason to expect the aliens to have developed arithmetic because that appears to be dictate of Reason, Dennett says. If the aliens had hands, with five digits each, they might even have a base-ten number system! But what would astound us beyond measure is if the aliens used numerals the same as ours. We recognize that numbers could be a sort of a Platonic category, but the lines and squiggles of numerals that came to represent our numbers are entirely accidental, are due to our particular cultural development.