The vitalist believes t h a t life cannot b e explained in terms of physics o r chemistry. In t h e nineteenth century, in Germany and France, a t least, his w a s t h e dominant voice before Darwin; and natural philosophers. such as Cuivier o r von Baer, o r Geoffrey St. Hilaire, dismissed mechanism with a kind of troubled confidence that suggests. in retrospect, a combination of assurance and wistful- ness. Orthodoxies have subsequently reversed themselves with no real gain in credibility. David Hull, in surveying this issue. concludes that neither mechanism nor vitalism is plausible, given t h e uninspiring precision with which each position is usually cast.[ll] D'dccord. To t h e e x t e n t t h a t t h e refutation of vitalism involves t h e reduction of biological to physical reasoning, t h e effort involved appears to m e misguided. and reflects a discreditable, almost oriental, desire for t h e Unity of Opposites. On t h e standard view of reduction, t h e sciences collapse downward until they hit physics: Rez-da-Chausee; but our intellectual experience is divided: mathematics. physics, biology, t h e social sciences. Each science extends sideways for some time and then simply stops. The a r d e n t empiricist, surveying t h e contemporary scene, might w e l l incline to scientific polytheism, with mathematics under t h e influence of an austere Artin-like figure, and biology directed by a God much like Wotan: furious, bluff. subtle, devious, and illiterate.
Still, t h e philosopher of science is bound to wonder why so many philose phers have remained partial to t h e reductionist vision, and hence to mechanistic thought in biology. David Armstrong. J.J.C. Smart, Michael Ruse, and even t h e usu- ally cagey W.v.0. Quine, call on elegance t o explain their attachment. Were t h e sci- ences irreducibly striated, one set of laws would cover physics, another biology, and still a third, economics and urban affairs, with t h e whole business resembling nothing so much as a parfait in several lurid and violently clashing colors. This is an aesthetic argument, and none t h e worse for that, but surely none t h e b e t t e r
The L a n g u a g e of Life 19
either. If elegance is inadequate as a motive, intellectual anxiety, realized uncons- ciously, is not. copper i t would conduct electricity as well. I t has often appeared t o philosophers of science t h a t specifying what i t means for something
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an z , say-
t o be much biology have a natural and legitimate interpretation in linguistic terms. I am myself indifferent t o t h e fate of t h e Darwinian theory, and perfectly prepared t o believe, along with Wickramasinghe and t h e luckless Hoyle, that life originated in outer space. o r t h a t t h e Universe-as-a-Whole is alive and breathing stertorously;20 D. Berltnskt
but if Darwinian theories work in life, they should work elsewhere
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in language- like systems, I should think. Should they fail t h e r e , this may be taken as evidence f o r t h e inadequacy of Darwinian theories, o r as evidence for t h e inadequacy of t h e analogy t h a t prompted t h e comparison in t h e f i r s t place.I stress this point if only because i t has so often been misunderstood.
Life as a language-Like system
It w a s von Neumann who gave t o t h e idea t h a t life is Like language a p a r t of i t s curious c u r r e n t cachet. The last years of his life h e devoted to a vast and clumsy orchestration of cellular automata. showing in a partial fashion t h a t when properly programmed they could, like a b s t r a c t elephants, reproduce themselves. Some years before. McCulloch and Pitts had constructed a series of neural nets in o r d e r to simulate simple reflex action; Kleene demonstrated t h a t their nets had t h e power of finite automata and were capable of realizing t h e class of regular events;
von Neumann's automata had t h e f u l l power of Turing machines. Michael Arbib, E.F.
Codd. G.T. Herman, A. Lindenmayer, and many others, have carried this work for- ward. with results t h a t asymptotically approach u t t e r irrelevance.[lZ] Yet t h e analogy between living systems and Living languages has not lost any of its brassy charm. There is information, of course, which is apparently what t h e genes store;
replication. coding; messages abound in t h e bacterial cell. with
E.
C o l i . in particu- lar, busy as a telephone switchboard. So striking has t h e appropriation of termi- nology become, t h a t some biologists now see t h e processes of life. in all their gran- deur, as t h e effort of a badly protected and vulnerable bit of genetic material t o keep t a k i n g for all eternity.UnIike an argument. an analogy stands o r falls in point of plausibility; good arguments in favor of bad analogies are infinitely less persuasive than bad argu- ments in favor of good analogies. Certainly t h e proteins. to stick with one class of chemicals. may be decomposed t o a finite base
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t h e 20 amino acids. The precise, delicate, dance-Like s t e p s t h a t are involved in their formation suggest, moreover, t h a t they satisfy some operation as abstract as concatenation. On the other hand, t h e number of possible proteins, although large, is finite; but one of t h e joys of analogical reasoning is t h e vagueness with which t h e line between success o r failure may be drawn.The grammatical strings of a language-like system a r e low in Kohogorov com- plexity, and so are not random. Such is t h e fastidiousness of a language-like sys- tem. What of t h e proteins?
If
they are random, i t makes Little sense to think of them as biological words o r sentences. Jacques Monod, whose metaphysical attitude toward biology suggested nothing so much as a kind of chirpy bleakness, drew attention t o t h e random c h a r a c t e r of t h e proteins inLa
h u s a r d et la necessite;his argument has been gravely accepted by many molecular biologists.[l3] In fact, t h e evidence leading t o his conclusion is fragmentary; the standards of random- ness to which h e appealed, imprecise. Thus it struck Monod that knowing, say, 249 amino acid residues in a chain 250 residues in length, one could yet not predict t h e last member of t h e chain; much t h e same is true for English sentences, of course; i t is, in any case, simply untrue t h a t protein strands exhibit such wanton degrees of freedom. Within protein chemistry, t h e r e a r e many instances of what appear t o b e strong internal regularities: palindromic patterns, for example.
The L a n g u a g e opL.tpe 21
Nonetheless, I am in sympathy with Monod t o this e x t e n t : i t is unlikely t h a t t h e analogy between life and language will b e profitably pursued on t h e atomistic level of t h e nucleic acids o r t h e proteins themselves.