Ing and oming M. Collins Searle is a philosopher at the Uniof California at Berkeley. In 1984 delivered the BBC Reith lectures, nting his reputation as one of the est a n d mos t forceful thinkers d. He is probably best known outhe professional heartland for his ese room' argument against artificial gence, which he repeated i n his lectures. Searle imagined a person room managing conversational interges i n Chinese b y manipulating ese word-symbols according to a rule the person i n the room might might not understand Chinese. Thus e proved to nearly everyone's satisn that symbol manipulation is not same as understanding. his latest book, Searle looks at the sciences. The title is provocative in it contrasts with that o f a famous by Peter Berger and Thomas Luck- , The Social Construction of Reality 7). Searle aims to show the difference een what can and what cannot be -ally constructed. On the way he devela refreshingly clear exposition of the ems o f the social sciences, in the ve sense o f problems tha t a re cult and interesting. arle explains that the social sciences, posed to the natural sciences, have to with things that exist only because we they exist. Take paper money: on the hand there is the actual paper and mg; on the other hand there is the e that resides in money only so long as one continues to believe, act and talk ough it is valuable. (Searle includes excellent discussion o f the role o f age in the creation of 'institutional '.) Once people stop thinking, talking acting collectively as though money is ble, it stops being valuable. This is a osophical puzzle because money is at at real in its effects as subatomic -cles - as the frustrated builders of Superconducting Super Col l ider Searle thinks, then, that there is al construction o f social things and t these things are nevertheless real. nce one sees that things that exist because we think they exist affect all lives in a way that is as concrete as can the recent arguments between natural social scientists are put into context. al scientists are surprised that natural ntists have difficulty with this kind of For example, Richard Dawkins URE • VOL 376 • 13 JULY 1995 Construction of Social Reality. By R. Searle. Free Press/Allen Lane: Pp. 241. $25, £20. insists that there are no social construetivist at 30,000 feet who aren't hypocrites, yet if he has money in his pocket he is a social constructivist himself. Where Searle differs from what he perceives to be the view of social construetivists is that he thinks the existence of social things presupposes a class of things that are there whether we think about them or not. I leave the details o f the argument to the reader. Agree with him or not, in putting the matter so clearly. Searle shows the way to the interesting questions. Is it true that social things are based on nonsocial things? I f it is true, where is the boundary between social and nonsocial? How do we tel l where the boundary is? What constraints do nonsocial things place on the construction of social things and vice versa? If some social scientists have overstepped the boundary - and this may be the cause of the heat in recent debates - how can we argue the matter sensibly? How can we investigate the way in which facts come into being without each side simply trying to impose its authority? Harry Collins is at the Science Studies Centre, University of Bath, Bath BA2 7AY, UK. Science evolving Ray Percival Evolutionary Naturalism. B y Michael Ruse. Routledge: 1995. Pp. 316. 135, $49.95. MICHAEL Ruse aims t o describe what scientists actually do in their research and how they arrive at their theories - a mixed bag o f false starts, fallacious reasoning, the cultivation o f followers, the marketing o f ideas and so on. His approach, evolutionary naturalism, rejects the traditional distinction between the normative and the descriptive analysis of science. For him the path of discovery to, say, Darwin's theory of natural selection makes a difference to the theory itself, whereas for the normative analyst it is just history. Normative analysts (who probably include most readers of Nature) would say that the logical structure of the theory, its truth or falsity and its relevance to the objective problem can al l be assessed independently of the route of discovery. A scientist's problem is to produce an explanatory theory of greater truth and depth than any rival theory; a look at the path o f discovery might give us hints about how t o interpret this objective problem situation. But, having said that, it is important to distinguish between Kekule's tail-biting snakes a n d h i s problem situation ( h o w t o explain benzene phenomena), a distinction one BOOK REVIEWS wishes Ruse had explored systematically. It is worth stressing that problems, which Ruse (following the philosopher Larry Laudan) believes introduce a n obviously subjective element, can b e treated as objective abstract entities. Anyone who doubts this can consult the surprisingly interesting Guidelines f o r Examination in the European Patent Office (European Patent Office, 1994). It is clear from this document that a person's subjective conception of an objective problem may be wrong and may fail to be decisive in the eventual solution. Ruse writes as if Karl Popper never said a word about the evolution of scientific theories from objective problems. Ruse's use of Thomas Kuhn to undermine Popper's falsification theory is a weak assault on normative analysis. In the Structure of Scientific Revolutions (University of Chicago Press, 1962), Kuhn says that "[no] process yet disclosed by the historical study of scientific development at all resembles the methodological stereotype of falsification by direct comparison with nature". This passage is the start of the myth that Popper was a naive falsificationist (that is, someone who believes in conclusive falsification) and o f the confusion that his falsificationism was an historical thesis. Falsificationism was meant as a normative proposal based on a logical analysis of the situation facing the scientist eager to learn from mistakes made in blindly groping for the truth. Only secondarily was it meant to suggest what actually happens in science. Nevertheless, there are many interesting examples that conform t o the pattern o f Popper's conjecture and refutation, for example Rutherford's refutation of J. J. Thomson's theory of the atom in 1911. (For more, see Popper's Realism and the Aim of Science, Hutchison, 1983). There are two strange things about the above passage from Kuhn. First, we are supposed to regard it as a falsification of falsificationism. But why should we, if, as Ruse insists, scientists ignore falsifications? The naturalist does not have an answer, because he cannot tell you what you should or should not do. Second, rhetorically the argument trades on the tacit assumption that scientists mostly get things mostly right (and if there is a best method, then they will be using this soon if not now). But, being fallible, all of them may one day get i t not just mostly, but completely wrong (or at least overlook a better method). And in fact, they have. The naturalist defines away this possibility. The normative analyst can also ask: how can we promote the growth of scientific knowledge? What method(s) should the scientist adopt if this is his aim? How should w e control error? A l l these questions are lost in naturalism. Ruse does shy away from a crude scientism that says that all problems can be 131 BOOK REVIEWS solved by science, but there are many forms o f naturalism and i t is unclear exactly where Ruse stands (see Susan Haack's Evidence and Enquiry (Blackwell, 1993) for clear distinctions and refutations of some forms of naturalism). In the section on evolutionary epistemology, Ruse argues t h a t scientific thinking (indeed, all thinking) is to be understood with the help of "epigenetic rules". These are rules of thinking that we are disposed to follow because of our evolutionary history, such as the law of non-contradiction. I f our ancestors were inclined to regard sabre-toothed tigers as both dangerous and not dangerous at the same time, they would not have been our ancestors. The approach is much more promising than that of, say, the philosopher David Hull, who sees the scientific success of a theory simply in terms of the proliferation of memetic copies, without considering the rational filters at work. But, although promising, Ruse's approach shows its defects when he goes on to say that the necessity of logical rules is based on nothing but our feelings of necessity shaped by evolution. He neglects the fact that conforming t o the law o f noncontradiction saves us from moving in an argument from true premises to a false conclusion, and also enables us to test the implications of our theories (because a false conclusion o f a valid argument implies a false premise). Logical necessity and validity are emergent properties of language and cannot be defined in terms of feelings (evolved or not). Such a view also neglects the most interesting thing about evolution - the emergence of radically new structures and properties not fully derivable from, contained in or explicable by those that came before. Once we have language, f o r instance, we can build theories that no one person can fully grasp: they are no longer just a part o f our psychology. Perhaps the ability to count, for example, was selected phylogenetically, but after Godel's famous incompleteness proof, we must say that the linguistically formulated theory of natural numbers has unfathomable content and that this is a fact independent o f the way we feel about the proof. I f this is not enough to convince Ruse that we are capable of producing systems that have independent properties, I would suggest looking at Danny Hillis's work, which suggests that self-evolving computer programs may produce perfectly working airline navigation systems containing millions of lines o f program that nobody could possibly understand. There arc surely elements of marketing in the selection of scientific theories, but, i f one wants to know about that, it is wise to consult advertising and marketing specialists. At the end of the day we have still to analyse what is the best method for enhancing the growth of scientific truth. 132 We can teach students how t o falsify theories and how to obtain jobs, and with enough ingenuity, there need be no conflict. I have focused mainly on a few problems in Evolutionary Naturalism, but i t covers in an informative way many other interesting areas. In the discussion of evolutionary ethics, for example, Ruse argues that our morals are, like our logic, based on biological evolution. The book is a readable and forthright presentation o f his views on the relevance of evolution to philosophy and could serve as a useful introduction for students. Ray Percival, an associate editor of Journal Relative values Sean Nee Macroecology. B y J a m e s H . B rown . University o f Chicago P r e s s : 1 9 9 5 _ Pp. 269. $42.50, 133.95 (hbk); $15.95, 112.75 (pbk). FROM 1736, generations of the Marsham family, who lived near Norwich, England, each year meticulously recorded facts such as the dates of the first snowdrops and cuckoos, resulting in an invaluable data set for studying how species respond to variations in climate. Darwin provides the best example o f how endless catalogues of facts about natural history, each fairly dull in itself, can be illuminating when looked at, imaginatively, as a whole. This stamp-collecting instinct is rife in ecology. Starlings weigh 80 grams and four million of them live in Sweden. Ecologists do not of course stare blankly at these facts, mesmerized. Rather, they ask how and why starling numbers have changed over time, and how a starling's weight affects its chances of surviving the winter. These questions take us in one direction, towards the particular. James Brown invites us to go in the other direction and to ask, for example, about the relationship between body size and abundance of birds in general - that is, to put all the facts into one big data set, to find empirical generalizations and to t ry to understand them. Clearly, there are many permutations. If we just look at the shape of the distribution of bird body sizes, we see that i t is skewed, with many more small species than medium or large ones. This is true not only for birds but for mammals, fish, trees, bacteria and insects as well, suggesting that there is a general principle to be unearthed. The main variables for which macroecologists have data are the body size, abundance, habitat specificity and geographical range of species, providing us with spaces of up to four dimensions in which to plot species points and look for interesting features in the resulting cloud. Brown demonstrates that with imaginative use of these data, meaningful hypotheses can be posed and many of their implications can be tested. This is not a "radical new research agenda", as the publishers would have us believe, although i t is interesting and important, and this is the first book to package the field for wide consumption. But i t does contain some radical ideas. For example, Brown offers an argument to explain the distribution of animal body sizes that defines fitness as the rate at which animals invest energy in reproduction. Because this invites us to discard current theories of life-history evolution, the author indeed "makes a major intellectual leap", but perhaps into the abyss. Our thinking about allometry is also challenged. I t is well known that larger mammals live longer, bear fewer young, have higher metabolic rates and so on. In other words, the relationship between body size and just about everything else is mono-tonic. Brown suggests that many of these relationships may in fact be triangular, with very small-bodied species showing the opposite overall trend. If true, this would be important. But so, far there is only anecdotal evidence, with one exception. Certain data sets reveal a triangular relationship between body size and abundance, with the most abundant species having intermediate sizes. B u t i t has been argued in the literature that the relationship is merely a sampling artefact, although Brown does not mention this. In fact, there is much that Brown does not discuss, and other macroecologists reading this book wil l , qui te rightly, be annoyed by the extent to which their work is ignored. One is given no hint, for example, tha t people have been using species–area relationships to predict extinctions for decades before the publication of a paper coauthored by Brown in 1992, which gets a chapter al l to itself. Nevertheless, Brown is a dominant figure in this field and his work is a suitable vantage point fo r an overview o f the macroecological research programme Sean Nee is in the Department of Zoology, University o f Oxford, South Parks Road, Oxford OXI, 3PS, UK. •The Chambers Dictionary of Science and Technology is 55 years old this year and was l as t revised seven years ago. The seventh edition, edited by Peter Walker, has just been published as the Larousse Dictionary of Science and Technology. I ts 1,236 pages contain 49,000 entries, over 500 illustrations and many appendices. Larousse, £45 (hbk),1,19.99 (pbk). NATURE • VOL 376 1 3 JULY 1995 Evc cot Naturg giving at the theory define a test, THE lenl their yo interacti work of that nat expressc equivalc degree t est, par amount subject content and on( mental faction wonder possible standin betweet Althoul togethe are nev theory applied social a the pri history within on the sion oi parent Pare selectic morph expre& parent descen assumi tive va to all i ences try to becau5. presen spring relate( relate( brood NATUF of Social and Evolutionary Systems, is at