Descartes argued that the one thing I cannot doubt is that I doubt, and that therefore I must exist as something whose essence is to think. The mind and its experiences were thereby made the starting-point and arbiter of certainty, and everything else, including the body, into a forever-doubtable "external world". Since Darwin, however, science has reversed this position. For contemporary philosophers, it is the internal world that is in doubt, since, as William Lyons, editor of Modern Philosophy of Mind, puts it, "Evolution is a seamless garment with no holes wherein souls might be inserted from above". Where in the centreless universe of scientific objectivity is there room for the self as perspectival centre of the world? And, as Hume asked: "Can anyone conceive a passion of a yard in length?" Subjectivity and mental states are spatially non-existent.

That does not make them less vital to us, often more real and certain than provable objective facts, which is where Descartes' intuition rings true and why the mind/body problem - the problem of the mind's place in nature - is so intractably at the forefront of contemporary philosophy. Modern Philosophy of Mind is a chronological series of articles on the subject written over the past 100 years, opening with a chapter from William James's Psychology: Briefer Course (1892). Something from James's more complex, analytic posthumously-published Essays in Radical Empiricism might have done him greater justice, except that this excerpt includes an insight sadly neglected in the 20th century debate, as is James himself - that it is not truly empirical to take isolated mental states as philosophical psychology's immediate datum, since how we actually experience them is as an interconnected "stream of consciousness" belonging to a self.

James's fluency and humanity make a significant contrast to the next article written 20 years later by behaviourist John B. Watson. "A perfectly adjusted organism would be lacking in conciousness," he says, and psychology should discard all reference to introspective mental states, employing the same objective empirical technique for humans as for rats, since he "recognises no dividing line between man and brute" (though he does distinguish between "savages" (some of the "Australian tribes") and "the educated European").

Excerpts from Rudolf Carnap, Wittgenstein and Ryle cover the next 40 years until identity theorists tried to reinstitute the privacy behaviourism abdicated, while preserving its scientific objectivity, by saying that the mind is nothing but the brain: it is inside you but it is physical. Two classic U.T. Place and J. J. Smart papers satisfactorily represent the pioneering of identity theory in the 1950s, but the refinement of this "Australian heresy" into type and token identity is only represented by means of a Donald Davidson article (unfortunately not the standard "Mental Events"). From the 1970s and 1980s, Putnam embodies the reaction against identity theory which refined behaviourism into computer functionalism (mind is to brain as a computer's program is to its hardware); and what Lyons in his introduction calls centralist and peripheralist funtionalisms are also well covered, though it seems sad to omit David Lewis's Martian feet.

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Paul Churchland (1981) is an appropriate spokesman for those Lyons calls "the hard men and women of 20th-century philosophy of mind", the eliminative materialists. Churchland claims that the vocabulary of feelings, sensations, beliefs, etc, constitutes a theory (of human functioning) which is as antiquated and redundant as alchemy or phlogiston, and which will ultimately be replaced as neurophysiology improves. The epitome of philosophical bizarreness and of the anti-Cartesian swing, eliminative materialism is pleasingly offset by Thomas Nagel's lucid championing of subjectivity in the famous "What is it like to be a bat?" (actually a challenge to functionalism). Finally, a 1989 article by Colin McGinn claims that it is "cognitive closure" - the discrepancy between our access to consciousness (by introspection) and to the brain (by ineluctably space-involving perception) - that forever debars our grasping whatever natural property in the brain constitutes the psychophysical link.

Suggestive, but pessimistic and perhaps question-begging, this is an odd piece with which to close the controversy, and the reader is left wondering what has been happening over the past six years, missing recent developments in cognitive psychology and connectionism. However, Lyons's anthology is not attempting to be as compendious as David Rosenthal's, as up-to-date as the specifiedly contemporary Cynthia and Graham Macdonalds' or Heil and Mele's, or as technical and specialised as Ned Block's or William G. Lycan's, and it excellently fills a gap as a non-specialised survey of the 20th-century mind/body debate. Inevitably, due to space constraints, it skimps in some areas, and is somewhat schematic, tending to suggest that there is a neat, discrete sequence of theories, rather than a constant modifying and intermeshing of pre-existing positions. But it is ideal for students (cheapness qualifying it as a course reader), and has a helpful introduction and illuminating historical chart aligning philosophical with historical, literary and scientific events.

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Gregory McCulloch in The Mind and Its World refocuses the mind/body problem by hitching it on to the current preoccupation with externalism (a theory which transposes the Hegelian view of individuals as constituted by their societies into a theory that: what is thought or said is constituted not by the intention and phenomenal/psychological circumstances of thinker or speaker but by objective features of the things thought or spoken about (or, in some versions, by the rules of the linguistic community)). Since behaviourism, McCulloch claims, the philosophy of mind has had a resurgence of Cartesianism, in that, however resolutely materialistic and naturalistic the equation of mind and brain, philosophers' concentration on functions like perception, information processing and reasoning has perpetuated Cartesian self-containment and divorce from the external world. In fact, identity theorists and functionalists are "materialistic Cartesians", and only rehash in a physical version the mental "idea" of Descartes and Locke. They treat perception as if it were only indirectly of things like tables, and directly of internal sense-impressions (brownness, squareness, hardness, smoothness, coldness, etc). But, McCulloch argues (citing Heidegger and Sartre, who in fact merely extended James's initial insight), we do not experience the world as the cobbled-together patchwork of an internal slide-show, rather as something we move through, intervene in, manipulate. And even when we do focus purely on the brownness of the table, "where do we experience (the brownness) as being? Where we always did, over there in the middle of the kitchen".

When conducting his polemic against "internalism", McCulloch's excitement and indignation are sometimes inspirational, enabling him immediately to convey complex thoughts. Often, however, the density and detail with which he outlines his own preferred externalist alternative clogs his communication of it, which makes it difficult to see what level of readership the book is aimed at. Academics would find the ideas, though not their combination, too familiar; first and second-year undergraduates might find their presentation too heavy-going.

Jane O'Grady is co-compiler with A.J. Ayer of A Dictionary of Philosophical Quotations and an extra-mural philosophy teacher for Birkbeck College, London.