Essay Review STEVEN ROSE

CAN PHILOSOPHY HELP BIOLOGY, OR PHILOSOPHERS UNDERSTAND BIOLOGISTS?

Alexander Rosenberg, Darwinism in Philosophy, Social Science and Policy (Cambridge: Cambridge University Press, 2000). 257 pp., ISBN 0-521-66407-1. Philosophy of science used to be a terrain colonized largely either by ex-physicists or trained philosophers attracted to the seeming certainties of physicist law-givers. Physics (and to a lesser extent, chemistry) has all the features a philosopher could desire. Its generalisations are universal, its regularities, dignified as laws, can be expressed with mathematical certainty, and its structures of experimental verification are models of clarity and precision. Even the theoretical debates within physics have become the stuff of philosophical analysis. The only other domain for philosophers appeared to be that provided by psychology, with its historical roots and current connections to the theory of mind and even consciousness. But as psychology merged into neuroscience in the 1960s, the space available for traditional philosophy seemed steadily to reduce. Recently, this has been vigorously re-occupied by a new group of ‘neurophilosophers’ (typified perhaps by Patricia Churchland), who are immensely attracted to the prospects of reducing both mind and brain to computational algorithms. How very different is the state of the biological sciences! Intensely empirical, our experimental findings are contingent and apparently incapable of generalisation, with virtually nothing recognisable as a ‘law’ in the sense that physicists know. Furthermore, biology was and is divided into numerous subsections, from animal behaviour and ecology to molecular biology, with seemingly few points of contact between these distinct disciplines. A delight to some who relish the infinite variety of ‘natural history’ and the pleasures of pluralism, these messy discourses, with their richness of data and inadequate standards of proof, have been a philosopher’s nightmare.

Minerva 40: 181–187, 2002. © 2002 Kluwer Academic Publishers. Printed in the Netherlands.

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This was so until the time when, perhaps a couple of decades ago, the shades of Popper were cast off, and the one seemingly ‘fundamental’ biological ‘law’ attracted the attention of philosophy. I am speaking, of course, of evolution by natural selection, the Darwinian insight which, at the beginning of this new century, seems to have colonized virtually all fields of intellectual inquiry.1 Darwinian evolution, dismissed half a century ago by Popper as untestable and therefore unscientific, became by the 1990s Daniel Dennett’s ‘universal acid’, a fundamental law of nature that eats through everything it touches, from physics to ethics and art appreciation. Hence it has become the focus of work for a new generation of philosophers of biology. Michael Ruse, the general editor of the series of Cambridge Studies in Philosophy and Biology, is typical in this context, and the series titles, ranging from Elliott Sober’s From a Biological Point of View, which appeared in 1994, to Alexander Rosenberg’s new book, reflect this focus. Indeed it would seem as if little else in biology interests such biological philosophers, though few of Ruse’s authors write with Dennett’s arrogant panache. How far such studies affect what we biologists actually do is another question entirely. Although most biologists would recognize the truth of Dobzhansky’s famous dictum that ‘nothing in biology makes sense except in the light of evolution’2 – and this is the dictum so readily seized upon by the new generation of philosophers of biology – the hard truth is that most biologists, molecular through to organismic, proceed in practice with complete indifference to such evolutionary concerns. It isn’t even that we are speaking prose without knowing; it is that evolutionary questions scarcely impinge upon our everyday work. However, for Rosenberg, ‘. . . the main principles of Darwin’s theory . . . are the only trans-temporally exceptionless laws of biology’ (p. 70). ‘The generalisations in biology which have consistently led to the discovery of new phenomena are those embodied in the theory of natural selection itself . . . evolutionary theory . . . has led repeatedly to the discovery of remarkable and unexpected phenomena. This should be no surprise since the theory of natural selection embodies the only set of laws – strict or non-strict – to be discovered in biology’ (p. 64). As Rosenberg fails to identify any of these ‘unexpected phenomena’, I am left puzzling a little as to what they might be. I assume that he is referring to selectionist accounts 1 See Hilary Rose and Steven Rose (eds.), Alas Poor Darwin: Arguments Against Evolutionary Psychology (London: Jonathan Cape, 2000). 2 I prefer ‘nothing in biology makes sense except in the light of history’, which embraces evolution, development, life-history and for humans – social, cultural and technological history, too. See S. Rose, Lifelines: Biology, Freedom, Determinism (Harmondsworth: Penguin, 1997).

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of adaptations, the mathematization of evolutionary stable strategies, sex ratios, and some of the sociobiological accounts of kin selection. Some of these would warrant a Popperian humph, as mere ‘just-so’ stories; others are indeed genuinely common-sensically surprising until explained as selective mechanisms. But, in most respects, Darwinian natural selection represents not so much a generator of unexpected findings as a marvellously satisfying synthetic account of one of the principal mechanisms by which life emerged from the primeval soup, and indeed how, in due course, both philosophers and biologists appeared on earth. Rosenberg’s argument that proper laws must be trans-temporal is itself problematic. On the one hand, even some physicists and cosmologists, such as Lee Smolin – attracted by Dennettian universal acids – are suggesting that the laws of physics themselves evolve.3 On the other hand, Rosenberg ignores the attempts to create a non-historical, structural biology, as in the work of Webster and Goodwin which would surely have suited his argument better.4 Webster and Goodwin claim, for instance, following a pre-Darwinian French tradition, that once the trans-historical laws of form have been identified, evolutionary studies will become ‘mere antiquarianism’. Is this really what Rosenberg wants? There is a certain irony in praising that supremely historical science of evolution as ‘transtemporal’. And for those of us who rejoice in biology’s essential historicity, this rejection of the very core of our subject’s style would seem at best quixotic. Further, Rosenberg’s exclusion of other law-like explanations of biological phenomena is definitely too restrictive. As a biochemist, I would point to the general principles of catalysis embodied in enzyme action, and, as an unexpected and surprising phenomenon, the theory of allosteric interactions in enzymology – neither of which can be derived from or owe specific allegiance to natural selection theory, although this theory can be invoked to explain how such mechanisms may have become better perfected over evolutionary time. This idealistic interpretation of what science is about is why philosophers such as Rosenberg are still able to dismiss much of biology as not properly scientific, a comment that reappears through several of the essays in his new collection.5 ‘Proper’ science must still conform to the physics model and, as it would appear from the quotation above, and 3 Lee Smolin, The Life of the Cosmos (London: Weidenfeld and Nicolson, 1997). 4 Gerry Webster and Brian Goodwin, Form and Transformation: Generative and

Relational Principles in Biology (Cambridge: Cambridge University Press, 1996). 5 I should declare an interest at this point. Rosenberg and I had a series of fairly sharp exchanges at a conference on reductionism in biology held in 2000 in Paris. The editor of Minerva was warned of this when I was invited to contribute this review. Fortunately, the

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others similarly dispersed through the volume, only Darwinian evolution can fit the bill. The eleven essays he reprints here, published originally at various times from 1987 to 2000, all loosely fit his title, ranging as they do from debates within philosophy proper – such as that over naturalistic ethics and eliminative materialism – to reflections on the utility – or otherwise – of evolutionary theory to economics, and the merits of the human genome project. The result is somewhat lacking in coherence. Present day philosophers, it seems to me, are rarely self-reflective. Rosenberg’s views – for instance on holism versus reductionism – shift significantly between the reprinted essays, and it would have been interesting for the reader to find him brooding on this, and his own intellectual trajectory, in his introduction, which is otherwise rather impersonal. Sociologists and historians of science, I find, seem to have little problem in accepting that science is what scientists do. So the biological sciences are indeed sciences; they are just different sorts of science from physics, which is after all but one small branch of the body of human knowledge about the world in which we live. Philosophers find this harder, which is partly why they are troubled by the lack of significant universal biological laws. Indeed, as Rosenberg points out himself, among the few generalisations dignified by the name of ‘law’ in biology, the best known are Mendel’s Laws in genetics, which turn out to be so replete with exceptions as to be no more than a very special case of the rules of genetic inheritance, and which furthermore, as he points out, do not map well onto current theories in molecular genetics. They thus do not meet the requirement of that sought-for philosopher’s stone, of being formally reducible. A proper science, Rosenberg implies, should be able to explain, not merely describe, the phenomena it studies. But he never reflects on what he regards as a proper explanation, rather than a description. When a physiologist refers to the cause of a muscle contraction as the firing of the motor nerve to that muscle, is that an explanation or a description? Following Tom Nagel,6 Rosenberg implies that this is merely a description; an explanation, although he never spells this out, would presumably require reducing the phenomenon to some more general statement in the molecular or atomic languages of physics and chemistry. Admittedly, towards the close of one of the central essays in this volume, he reluctantly concedes that such unreduced explanations may be the best we can do differences between us at that meeting only peripherally impinge on the subject matters of the essays under review here. 6 See my discussion with Nagel in the Ciba Foundation symposium, The Limits of Reductionism in Biology (London: Wiley, 1997).

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– that the limitations of our evolved minds mean that biology can never become a full science in the sense of physics, and we may have to put up with explanations that are emotionally but not rigorously philosophically satisfying. If this were to be the case, so much the worse for philosophy. After all, neither explanations nor descriptions exist in some philosophical vacuum outside human concerns; they are accounts of phenomena that humans give for a purpose, and the purpose for which a physiologist may wish to discuss muscle contraction may very well mean that talking about a prior nerve impulse has greater explanatory power than a discussion of ions moving across a cell membrane or the sliding of the actin and myosin protein filaments which constitute the macromolecular constituents of the muscle. Such a molecular account may indeed be a mere description, missing some essential explanatory element of the phenomenon, such as its function in the life of the organism, and therefore failing to provide the explanation required by physiology. And just why a philosopher has the right to adjudicate that such a physiological account should fall ‘so far short of scientific adequacy’ (p. 71) tells us more about philosophical arrogance than it does about how to do science. But to concede that either explanations or descriptions are human tools moves closer than Rosenberg is prepared to go to social constructionism, which for him is the ultimate cop-out. This tension is most apparent in the two most biologically central of the essays. The first of these, ‘Reductionism Redux’, takes as its starting point the claim, by the developmental biologist Lewis Wolpert in his book The Triumph of the Embryo, that ultimately the embryo may be computable – that is, predictable from a full knowledge of its DNA content. The second, ‘What Happens to Genetics when Holism Runs Amok?’, reflects on a prior paper by Griffiths and Grey arguing for a developmental systems approach to understanding life processes. Oddly, Rosenberg seems sympathetic to both positions, as if in the three years between the two essays he has sharply shifted his views. It is here that I would have preferred a little debate between Rosenberg a and Rosenberg b, but his authoritative style will not permit such mischievous reflections. As it happens, my own prior review of Wolpert’s book specifically criticized his claim as to the potential computability of the embryo, as ignoring the shaping power of both temporal and spatial constraints. Rosenberg sees this as a claim to ‘downward causation’, a pernicious idea due, I believe, originally to Roger Sperry. But for those who like myself embrace an autopoietic viewpoint on development – the term originally provided by Humberto Maturana and Francisco Varela – ‘downward causation’ is as absurd a concept as ‘upward

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causation’, confusing as it does the question of levels of organisation in biological systems and – oddly for a philosopher – failing to distinguish between even the various uses of the word ‘cause’ which date back to Aristotle. Insofar as Rosenberg (at least in his b version) sympathizes with the developmental systems perspective offered by Griffiths and Grey, and distances himself from Wolpertian triumphalism, I am happy indeed to go along with him. As he points out, because adaptive strategies interact, ‘timeless truths in terrestrial biology [are] impossible to come by’ (p. 114), and biology’s ‘regularities and models . . . will never give rise to anything recognizably nomological by the lights of physical science, but . . . are indispensible for all that’ (pp. 115–116). Cheers! The essays that follow reflect critically on the increasing tendency to seek evolutionary justifications for moral ethical and social dilemmas. Is an ‘evolutionary code of ethics’ based on a better understanding of human nature – as E.O. Wilson, and following him new generations of evolutionary psychologists argue – possible or desirable? Rosenberg is rightly dubious, although it is a pity that this essay, dating from 1990, could not have been updated to take into account more current claims, such as those of Geoffrey Miller.7 Something of the same problem afflicts the otherwise welcome critique of evolutionary economics that follows. By focusing his critique on the work of Alchian dating from 1950, he misses the dubious flowering of this new mix of metaphor and misunderstanding that the evolutionary economics of the 1990s have generated. Nonetheless, the critical analysis of what might be the best case scenarios for such evolutionary claims is welcome, although more robustly dealt with in a recent book edited by Hardcastle.8 Rosenberg’s collection ends with a rather weak and dated essay on the Human Genome Project, which concludes with the view that it should never have been state financed, but left to private venture capital and market forces – which in practice would probably have meant Craig Venter owning patents on the entire genome (and as a result, perhaps, no one being able to propagate their own genes except under a Venter licence). The remaining essays in the book deal with primarily philosophical issues, including a major analysis of naturalist epistemology, following Quine. As a non-philosopher I found these informative, if not exactly easy reading, but it would be even more presumptious of me than usual to venture too far into what is, after all, the philosopher’s rather than the 7 Geoffrey Miller, The Mating Mind: How Sexual Choice Shaped the Evolution of

Human Nature (Oxford: Heinemann, 2000). 8 Valerie Gray Hardcastle (ed.), Where Biology Meets Psychology: Philosophical Essays (Cambridge, MA: MIT Press, 1999).

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biologist’s terrain. But my impression remains, now having read several books in the Cambridge series, that the venture of bringing philosophy to bear on biology is too important to ignore. And I don’t mean just for philosophers. A science which is ignorant of its own history and indifferent to its own epistemology is fatally flawed, and this is the condition in which most biological research is conducted. However, it cannot be done in the rather abstract way that Rosenberg’s – or even Sober’s – approach implies. One of the attractive features of the new work coming from the neurophilosophers, like Patricia Churchland, for instance – is that its authors have actually gone to the extent of immersing themselves in the day-to-day working lives of neurophysiological and behavioural laboratories. Perhaps an exchange programme that brought philosophers into ecology and molecular biology labs is what is now needed, if we are to move forward.

A BOUT THE AUTHOR Steven Rose is Professor of Biology and Director of the Brain and Behaviour Research Group at the Open University, and joint Professor of Physic at London’s Gresham College. A neuroscientist by profession, his recent books include Lifelines: Biology, Freedom, Determinism (Harmondsworth: Penguin, 1997) and, jointly edited with the sociologist Hilary Rose, Alas Poor Darwin: Arguments against Evolutionary Psychology (London: Jonathan Cape, 2000).

The Open University Milton Keynes MK7 6 AA UK E-mail: [email protected]