Jean-Paul and co. get lost in a J, U, N, G, L, E

Organisation is this book's strong suit. Arranged around eight central concepts - mind, knowledge, language, science, morality, politics, law and metaphysics - this is as clear a horizon as anyone making le tour could wish. Its weakness is its prose, which, despite being described on the dust jacket's as "vivid" and "witty", is as dense as the forests of the Congo where Kwame Appiah sets the opening of one of his chapters.

Why do publishers allow such claims to appear? Does everything have to be made simple? My academic friends are agog at the fall-off in admissions for "difficult" degrees - mathematics, physics and chemistry and certain "hard" languages in particular. The fact is surely this: many areas of human activity are difficult, can never be made easy and are all the more rewarding for that. There is no point in blinding ourselves to this.

Is contemporary philosophy difficult? I rather think that Appiah makes it appear so. Many pages are filled out with either indigestible jargon - "sentence-forming operators", "intentional contexts", "equilibrium strategy pairs" - printed in bold, or else consist largely of letters standing alone for this or that premise. Appiah says that his aim in this book is to make his readers more comfortable with the "many possibilities" when addressing the philosophical questions that trouble us. I can only say that I found the constant switch between individual L, E , T , T , E, R , S rather discomfiting.

Although I enjoyed Appiah's discussion of John Rawls' "veil of ignorance" and Robert Nozick's riposte (considered under "politics" rather than "morality"), the chapters on science and metaphysics are best, perhaps because they are notably short of jargon and bold typeface. His outline of John Hick's arguments about theodicy is especially clear. And maybe there is a moral here. Are these chapters the success they are because science and metaphysics address real concerns, real questions relating to real entities, as opposed to some of the highly artificial problems entertained by philosophers of language, politics and even law?

As a Ghanaian at Princeton University, Appiah has a keen interest in anthropology, and this gives the book an occasional lift. There is, for example, an excellent section on the implications of literacy for philosophy that could well have been expanded.

I could find no definition of what he means by "contemporary philosophy". Of the 20th-century philosophers left out of the book, the biggest gaps concern logical positivism and existentialism. There is no mention of the Vienna Circle, or of Edmund Husserl, Martin Heidegger, Karl Jaspers or Jean-Paul Sartre. These omissions are all the more striking when Appiah refers freely to Plato, Aristotle, Hobbes, Fichte, Hegel and even Frege.

And since the modern age is generally understood, in philosophical terms at any rate, as beginning when the discipline transferred its allegiance from theology to science, this is a doubly curious omission.

If Appiah wants to write an accessible introduction to philosophy, he should try his hand at a narrative history. When he allows himself this approach in this book, the dense prose suddenly clears, the shadows sharpen and the way forward is there for all to see. Here is one reader who could take more of that.

Peter Watson is the author of A Terrible Beauty : The People and Ideas Who Shaped the Modern Mind .