Acknowledgments In its first incarnation, this book was a series of three lectures pre- sented in the summer of 1997 to the Facolta di Psicologia, Università San Raffale, under the sponsorship of the Sigma Tau Foundation. I’m grateful to an old Italian friend, Professor Massimo Piatelli, for having arranged the occasion; to many new Italian friends for comments and criticism; and to Dr. Donata Vercelli for having steered me through a traumatic loss of credit cards, the ultimate Jamesian crisis for an American abroad. All of the following did me the great kindness of reading through earlier versions of part or all of the manuscript and help- ing me to catch the mistakes. Much gratitude to: Ned Block, Noam Chomsky, Shaun Nichols, Zenon Pylyshyn, and Stephen Stich. The appendix was first published in Cognition. Permission to reprint is gratefully acknowledged. Not one red cent was contributed to the support of this work by: The MacArthur Foundation, the McDonnell Pugh Foundation, the National Science Foundation, or the National Institutes of Health. The author is listed alphabetically. Introduction: Still Snowing Over the years, I’ve written a number of books in praise of the Computational Theory of Mind (CTM often hereinafter). It is, in my view, by far the best theory of cognition that we’ve got; indeed, the only one we’ve got that’s worth the bother of a seri- ous discussion. There are facts about the mind that it accounts for and that we would be utterly at a loss to explain without it; and its central idea—that intentional processes are syntactic operations defined on mental representations—is strikingly ele- gant. There is, in short, every reason to suppose that the Computational Theory is part of the truth about cognition.1 But it hadn’t occurred to me that anyone could think that it’s a very large part of the truth; still less that it’s within miles of being the whole story about how the mind works. (Practitioners of artificial intelligence have sometimes said things that suggest they harbor such convictions. But, even by its own account, AI was generally supposed to be about engineering, not about sci- ence; and certainly not about philosophy.) So, then, when I wrote books about what a fine thing CTM is, I generally made it a point to include a section saying that I don’t suppose that it could com- prise more than a fragment of a full and satisfactory cognitive psychology; and that the most interesting—certainly the hard- est—problems about thinking are unlikely to be much illumi- nated by any kind of computational theory we are now able to imagine. I guess I sort of took it for granted that even us ardent admirers of computational psychology were more or less agreed on that. I am now, however, disabused of taking that for granted. A couple of years ago, The London Review of Booksasked me to write about two new publications, each of which summarized and 2 Introduction commended a theory that is increasingly influential in cognitive science: Steven Pinker’s How the Mind Works and Henry Plotkin’s Evolution in Mind. These books suggest, in quite similar terms, how one might combine CTM with a comprehensive psycholog- ical nativism and with biological principles borrowed from a neo-Darwinist account of evolution. Pinker’s and Plotkin’s view appears to be that the resulting synthesis, even if it doesn’t quite constitute a general map of the cognitive mind, is pretty much the whole story about large areas of Manhattan, the Bronx, and Staten Island. I thought both books admirable and authoritative in many respects; but, though I’m a committed—not to say fanat- ical—nativist myself, I wasn’t entirely happy with either, and I said so in my review.2 For one thing, although they accurately set out a network of doctrines about the cognitive mind that many nativists hold, nei- ther book makes as explicit as I thought it might have how the various strands fit together. For a second thing, though neither book spends a lot of time on the alternatives, the Pinker/Plotkin view is by no means the only kind of current cognitive science that’s friendly to the idea that lots of knowledge is innate. Indeed, Noam Chomsky, who is surely as close to personifying the nativist revival as anybody can get, is nevertheless quite out of sympathy with much of what Pinker and Plotkin endorse. Readers who are new to the cognitive science game may well find this puzzling, but I hope to make it clear as we go along what the disagreement is about. Third, both books insist on a connection between nativism about cognition and a neo- Darwinist, adaptationist account of how the cognitive mind evolved. That struck me as neither convincingly argued in the texts nor particularly plausible in its own right. Finally, I was, and remain, perplexed by an attitude of ebullient optimism that’s particularly characteristic of Pinker’s book. As just remarked, I would have thought that the last forty or fifty years have demon- strated pretty clearly that there are aspects of higher mental processes into which the current armamentarium of computa- tional models, theories, and experimental techniques offers van- ishingly little insight. And I would have thought that all of this is Introduction 3 common knowledge in the trade. How, in light of it, could any- body manage to be so relentlessly cheerful? So, it occurred to me to write a book of my own. I had it in mind to pick up some old threads in passing; in particular, I wanted to extend a discussion of the modularity (or otherwise) of cognitive architecture that I’d first embarked upon a million years or so ago in (Fodor 1983). But the book I thought I’d write would be mostly about the status of computational nativism in cognitive science. And it would be much shorter, and much more jaundiced, than either Pinker’s or Plotkin’s. The shortness would be mostly because, unlike them, I wasn’t going to write an intro- ductory text, or to review the empirical cognitive science litera- ture, or even to argue in much detail for the account of the field I would propose. I’d be satisfied just to articulate a geography of the issues that’s quite different from the map that Pinker and Plotkin have on offer. The jaundice would be mostly in the con- clusion: Computational nativism is clearly the best theory of the cognitive mind that anyone has thought of so far (vastly better than, for example, the associationistic empiricism that is the main alternative); and there may indeed be aspects of cognition about which computational nativism has got the story more or less right. But it’s nonetheless quite plausible that computational nativism is, in large part, not true. In the fullness of time, I embarked upon that project, but the more I wrote, the unhappier I became. I’d started off intending to take CTM more or less for granted as the background theory and to concentrate on issues about nativism and adaptationism. But in the event, that turned out not to be feasible; perhaps unsur- prisingly, what one says about any of these matters depends very much on what one thinks about the others. There are many claims about nativism, and about adaptation- ism, in the book I ended up with (and which, I trust, you have just purchased). But part of the context for discussing them is an attempt to get clearer on what’s right, and what’s wrong, about the idea that the mind is a computer.3 The cognitive science that started fifty years or so ago more or less explicitly4 had as its defining project to examine a theory, 4 Introduction largely owing to Turing, that cognitive mental processes are operations defined on syntactically structured mental represen- tations that are much like sentences.5The proposal was to use the hypothesis that mental representations are languagelike to explain certain pervasive and characteristic properties of cogni- tive states and processes; for example, that the former are pro- ductive and systematic, and that the latter are, by and large, truth preserving. Roughly, the systematicity and productivity of thought were supposed to trace back to the compositionality of mental representations, which in turn depends on their syntactic constituent structure. The tendency of mental processes to pre- serve truth was to be explained by the hypothesis that they are computations, where by stipulation a computation is a causal process that is syntactically driven.6 I think that the attempt to explain the productivity and sys- tematicity of mental states by appealing to the compositionality of mental representations has been something like an unmiti- gated success;7 in my view, it amply vindicates the postulation of a language of thought. That, however, is a twice-told tale, and I won’t dwell on it in the discussion that follows. By contrast, it seems to me that the attempt to reduce thought to computation has had a decidedly mixed career. It’s a consolation, however, that there is much to be learned both from its successes and from its failures. Over the last forty years or so, we’ve been putting questions about cognitive processes to Nature, and Nature has been replying with interpretable indications of the scope and limits of the computational theory of the cognitive mind. The resultant pattern is broadly intelligible; so, at least, I am going to claim. Before the discussion gets seriously under way, however, I want to sketch a brief overview for purposes of orientation. Here, in a nutshell, is what I think Nature has been trying to tell us about the scope and limits of the computational model: It’s been pretty clear since Freud, that our pretheoretical, “folk” taxonomy of mental states conflates two quite different natural kinds: the intrinsically intentional ones, of which beliefs, desires, and the like are paradigms;8 and the intrinsically con- Introduction 5 scious ones, of which sensations, feelings, and the like are para- digms.9,10Likewise, I claim, a main result of the attempt to fit the facts of human cognition to the classical, Turing account of com- putation is that we need a comparably fundamental dichotomy between mental processes that are local and ones that aren’t. There is (I continue to claim) a characteristic cluster of properties that typical examples of local mental processes reliably share with one another but not with typical instances of global ones.11 Three of these features are most pertinent to our purposes: Local mental processes appear to accommodate pretty well to Turing’s theory that thinking is computation; they appear to be largely modular; and much of their architecture, and of what they know about their proprietary domains of application, appears to be innately specified. By contrast, what we’ve found out about global cognition is mainly that it is different from the local kind in all three of these respects; and that, because it is, we deeply do not understand it. Since the mental processes thus afflicted with globality appar- ently include some of the ones that are most characteristic of human cognition, I’m on balance not inclined to celebrate how much we have so far learned about how our minds work. The bottom line will be that the current situation in cognitive science is light years from being satisfactory. Perhaps somebody will fix it eventually; but not, I should think, in the foreseeable future, and not with the tools that we currently have in hand. As he so often does, Eeyore catches the mood exactly: “‘It’s snowing still,’ said Eeyore, ‘. . . and freezing. . . . However,’ he said, brightening up a little, ‘we haven’t had an earthquake lately.’” This, then, is the itinerary: In chapter 1, I set out some of the main ideas that are currently in play in nativistic discussions of cognition. In particular, I want to distinguish the synthesis of nativism, computational psychology, and (neo-)Darwinism that Pinker and Plotkin both endorse from Chomsky’s story about innateness. Chomskian nativism and this New Synthesisl2are, in some respects, quite compatible. But as we’ll see, they are also in some respects quite different; and even when they endorse the same slogans, it’s often far from clear that they mean the same 6 Introduction things by them. For example, Chomskian nativists and compu- tational nativists both view themselves as inheriting the tradi- tion of philosophical rationalism, but they do so for rather different reasons. Chomsky’s account (so I’ll suggest) is primar- ily responsive to questions about the sources and uses of knowl- edge, and so continues the tradition of rationalist epistemology. Computational nativism, by contrast, is primarily about the nature of mental processes (like thinking, for example) and so continues the tradition of rationalist psychology. I expect that much of what I’ll have to say in the first chapter will be familiar to old hands, and I’d skip it if I could. However, standard accounts of New Synthesis cognitive psychology (including, notably, both Pinker’s and Plotkin’s) often hardly mention what seems to me be overwhelmingly its determining feature, namely, its commitment to Turing’s syntactic account of mental processes. Leaving that out simplifies the exposition, to be sure; but it’s Hamlet without the Prince. I propose to put the Prince back even though, here as in the play, doing so makes no end of trouble for everyone concerned. Much of this book will be about how the idea that cognitive processes are syntactic shapes the New Synthesis story; and why I doubt that the syntactic the- ory of mental processes could be anything like the whole truth about cognition, and what we’re left with if it’s not. The second chapter will discuss what I take to be the limita- tions of the syntactic account of the mental, and chapter 3 will consider some ways in which computational nativists have tried, in my view not successfully, to evade these limitations. In chapter 4, the currently fashionable “massive modularity thesis” will emerge as one such failed way out. The last chapter con- cerns the connection of all of this to issues about psychological Darwinism. It will become clear, as the exposition proceeds, that I think some version of Chomskian nativism will probably turn out to be true and that the current version of New Synthesis nativism probably won’t. I suspect that the basic perplexity of the New Synthesis is that the syntactic/computational theory of thought that it depends on is likely to hold for cognitive processes in gen- Introduction 7 eral only if the architecture of the mind is mostly modular— which, however, there is good reason to suppose that it isn’t. On the other hand, a tenable cognitive psychology does urgently need some theory of mental processes or other, and Chomsky rather clearly doesn’t have one. So if computational nativism is radically untenable, Chomskian nativism is radically incomplete. Ah, well, nobody ever said that understanding the cognitive mind was going to be easy. At least, I’m pretty sure that I never did. In fact, for whatever it may be worth, my views on these matters haven’t changed much since I started writing about this sort of topic. It’s the main point of the last chapter of The Language of Thought (1975) that the computational model is implausible as an account of global cog- nition. And it’s a central theme in The Modularity of Mind (1983) that modular cognition is where Turing’s computational story about mental processes is most likely to be true. Consistency over time isn’t a virtue I generally care a lot about. In my experi- ence, scientific progress (to say nothing of philosophical progress) is nonmonotonic as often as not. I admit, however, that the present doctrines are compatible with—indeed, that they mostly elaborate upon—several of my earlier attempts. Finally, while I’m in this confessional mood, I should empha- size that what follows, though it proposes a reading of the recent history of cognitive science, isn’t remotely a work of scholarship. Various familiar names (Eeyore, of course; but also Chomsky, Darwin, Hume, Kant, Plato, Turing, and others) will appear from time to time, and perhaps it goes without saying that I’ll be pleased if I’ve reported their views more or less correctly. But my main concern is to explicate such options for a nativistic cogni- tive science as are currently visible, and I’ll generally think of the distinguished persons we meet along the way much less as his- torical figures than as ideal types. So then, to work at last. Chapter 1 Varieties of Nativism Chomsky’s Nativism The present phase of nativistic theorizing about the cognitive mind began with two suggestions of Noam Chomsky’s: that there are substantive, universal constraints on the kinds of gram- mars that natural languages can have; and that these constraints express correspondingly substantive and universal properties of human psychology (determined, presumably, by the characteris- tic genetic endowment of our species). In effect, Chomsky pre- dicted the convergence of two lines of research: • On the one hand, empirical investigation of the range of grammatical structures that human languages exhibit would estimate the limits within which it is possible for them to vary. One then subtracts the ways that human lan- guages can differ from the ways in which it is conceivable that languages could differ. The remainder after the sub- traction is the set of linguistic universals that implicitly define “possible human language.”1 • On the other hand, empirical investigations of the condi- tions under which children learn to talk would estimate the information their linguistic environments provide, hence how much poverty of the stimulus the language learning process tolerates. One then subtracts the information that is in the environment from the information that is required for the child to achieve linguistic mastery. The remainder after the subtraction is what the child’s innate knowledge contributes to the language acquisition process. If everything goes well, it should turn out that what the child innately knows will be the same universal principles that constrain