The papers collected in this volume are the proceedings of the 1999 Royal Institute of Philosophy conference: the theme of the conference, the same as the title of this collection, Naturalism, Evolution and Mind. The essays collected here cover a wide array of disparate themes in philosophy, psychology, evolutionary biology and the philosophy of science. They range in subject matter from the mind/body problem and the nature of philosophical naturalism, to the naturalization of psychological norms to the naturalization of phenomenal and intentional content, from the methodology cognitive ethology to issues in evolutionary psychology. They are united by the simple thought that the great promise of current naturalism in philosophy of mind resides in its potential to reveal mental phenomena as continuous with other phenomena of the natural world, particularly with other biological phenomena.

By now, even the kid down the street must be familiar with the functionalist's response to type-identity physicalism. Mental kinds like pain, love, the belief that Madison sits on an isthmus, etc., are not identical to physical kinds because it's conceptually (if not empirically) possible that entities physically distinct in kind from human beings experience pain, love, beliefs that Madison sits on an isthmus, etc. Type-identity physicalism, in short, is baselessly chauvinistic in its rejection of the possibility of nonhuman minds.

One goal of recent philosophy of mind has been to ‘naturalize’ intentionality by showing how a purely physical system could have states that represent or are about items (objects, properties, facts) in the world. The project is reductionist in spirit, the aim being to explain intentional relations—to say what they really are—and to do so in terms that do not themselves utilize intentional or semantic concepts. In this vein there are attempts to explain intentional relations in terms of causal relations, informational relations, teleological or functional relations, relations involving abstract similarity or isomorphism, and various combinations thereof. What makes these accounts naturalistic is the presumed objectivity and scientific respectability of the properties appelated to in the explanans. What makes them all reductive is their shared presumption that intentionality can be explained in terms that have a wider application to intentional systems as well as to systems that have no mental properties at all.

My topic in this chapter is whether phenomenal consciousness can be given a reductive natural explanation. I shall first say something about phenomenal—as opposed to other forms of—consciousness, and highlight what needs explaining. I shall then turn to issues concerning explanation in general, and the explanation of phenomenal consciousness in particular.

Many people think the mind evolved. Some of them think it had to evolve. They think the mind not only has a history, but a history essential to its very existence.

‘According to informational semantics, if it's necessary that a creature can't distinguish Xs from Ys, it follows that the creature can't have a concept that applies to Xs but not Ys.’ (Fodor, 1994, p. 32)

There is, indeed, a form of informational semantics that has this verificationist implication. The original definition of information given in Dretske's Knowledge and the Flow of Information (1981, hereafter KFI), when employed as a base for a theory of intentional representation or ‘content,’ has this implication. I will argue that, in fact, most of what an animal needs to know about its environment is not available as natural information of this kind. It is true, I believe, that there is one fundamental kind of perception that depends on this kind of natural information, but more sophisticated forms of inner representation do not. It is unclear, however, exactly what ‘natural information’ is supposed to mean, certainly in Fodor's, and even in Dretske's writing. In many places, Dretske seems to employ a softer notion than the one he originally defines. I will propose a softer view of natural information that is, I believe, at least hinted at by Dretske, and show that it does not have verificationist consequences. According to this soft informational semantics, a creature can perfectly well have a representation of Xs without being able to discriminate Xs from Ys.

Our reading is a passage from John Locke, An Essay Concerning Human Understanding, Book III, Chapter II, § 2.

When a man speaks to another, it is that he may be understood; and the end of speech is that those sounds, as marks, may make known his ideas to the hearer. … Words being voluntary signs, they cannot be voluntary signs imposed by him on things he knows not. That would be to make them signs of nothing, sounds without signification.

When I woke up a few days ago, the following thoughts ran through my mind. ‘I need a haircut. If I don't get it first thing this morning, I won't have another chance for two weeks. But if I go to the barber down the road, he'll want to talk to me about philosophy. So I'd better go to the one in Camden Town. The tube will be very crowded, though. Still, it's a nice day. Why don't I just walk there? It will only take twenty minutes. So I'd better put on these shoes now, have breakfast straight away, and then set out for Camden.’

According to the rationality thesis, the possession of propositional attitudes is inextricably tied to rationality. How in this context should we conceive of rationality? In one sense, being rational is contrasted with being non-rational, as when human beings are described as rational animals. In another sense, being rational is contrasted with being irrational. I shall call rationality in this latter sense evaluative rationality. Whatever else it might involve, evaluative rationality surely has to do with satisfying requirements of rationality such as, presumably, the following:

(1) That one avoid inconsistency in beliefs.

(2) That one not adopt new beliefs unless what one knows entails or is evidence for the truth of those beliefs.

(3) That one not have φing as a goal yet do nothing necessary for one to φ. (Means/end requirement.)

It is now over twenty years since Premack and Woodruff (1978) posed the question, ‘Does the chimpanzee have a theory of mind?’—‘by which we meant’, explained Premack (1988) in a later reappraisal, ‘does the ape do what humans do: attribute states of mind to the other one, and use these states to predict and explain the behaviour of the other one? For example, does the ape wonder, while looking quizzically at another individual, What does he really want? What does he believe? What are his intentions?'

Philosophy of mind is, and for a long while has been, 99% metaphysics and 1% epistemology. Attention is lavished on the question of the nature of mind, but questions concerning how we know about minds are discussed much less thoroughly. University courses in philosophy of mind routinely devote a lot of time to dualism, logical behaviourism, the mind/brain identity theory, and functionalism. But what gets said about the kinds of evidence that help one determine what mental states, if any, an individual occupies? Well, Skinner's puritanical disdain for postulating mental states gets raked over the coals, the problem of other minds gets solved by a perfunctory invocation of the principle of inference to the best explanation, and the Turing test gets discussed, mainly in order to emphasize that it can lead to mistaken answers.

According to Darwinian thinking, organisms are (for the most part) designed by natural selection, and so are (for the most part) integrated collections of adaptations, where an adaptation is a phenotypic trait that is a specialized response to a particular selection pressure. For animals that make their living in the Arctic, one adaptive problem is how to maintain body temperature above a certain minimum level necessary for survival. Polar bears' thick coats are a response to that selection pressure (surviving in extreme cold). A thick coat makes a positive difference to a polar bear's fitness, since polar bears with very thin coats left fewer offspring than those with thicker coats. The foundational idea of evolutionary psychology is that brains are no different from any other organ with an evolutionary function, insofar as brains too are systems shaped by natural selection to solve adaptive problems. Thus brains have a particular functional organization because their behavioural effects tend, or once tended, to help maintain or increase the fitness of organisms with those brains. Prominent evolutionary psychologists (for example: Cosmides and Tooby, 1987; Cosmides and Tooby, 1994 and Symons, 1992) have endorsed the view that the last time any significant modifications were made by natural selection to the human brain's functional architecture, we were hunter-gatherers, inhabiting a world quite different from that which we now inhabit. That world was the Pleistocene epoch, between about 2 million years ago and 10 thousand years ago. On this view, then, the Pleistocene constitutes what evolutionary psychologists often call our environment of evolutionary adaptedness (or EEA), and the information- processing structure and organization of our present-day cognitive architecture is no different from that of our recent huntergatherer ancestors.

There is a close coincidence in time between the appearance of psychology as a science and the rise of evolutionary theory. The first laboratory of experimental psychology was established in Germany by Wilhelm Wundt just as Darwin's writings were beginning to have their enormous impact, especially as they might be applied to understanding the human mind (Darwin, 1871). Psychology is an important discipline because it straddles the boundary between the biological sciences and the social or human sciences (defined as those sciences that study exclusively human characteristics) of anthropology, sociology and economics. Given that importance, and given that new sciences lack the conceptual history within which older, established sciences might be mired, it might have been expected that psychology would have embraced in a way that established sciences did not the equally new, sensational and central theorem of biology which spoke to the origins of species as well as the origins of their traits and, crucially, the functions of those traits. Yet for over a century evolutionary theory had virtually no presence in psychology, despite having powerful friends like William James at court (James, 1880).