Spanner in the works

According to the publisher's blurb, " The Philosopher's Toolkit is essential reading for anyone who wants to philosophise well".

This is an absurdly inflated claim. The authors assume that "philosophising" is an activity best done by mastering certain intellectual "tools" -"tools for argument" (such as deduction, induction and definition), "tools for assessment" (such as Leibniz's law and Ockham's Razor), "tools for conceptual distinctions" (such as analytic/synthetic and essence/accident) and so on. Thus the book doubles as a textbook of critical thinking and a philosophical dictionary. It is aimed at novice students and general readers, though many further reading suggestions would be beyond the capacities of this audience.

The book is not a reliable guide and contains many errors and oversimplifications. For example, the authors suggest that the law of non-contradiction is unchallengeable, ignoring the dialetheism of Graham Priest. They make no mention of opacity while claiming that the Masked Man fallacy turns on the allegedly "misleading" formulation of Leibniz's law as "X and Y are identical if (sic) what(ever) is true of X is true of Y".

There are blunders of a more trivial character, such as the remark that water boils owing to "the increase in the Brownian motion of the H20".

Equally irritating are the feeble jokes (formal logicians are "not concerned with tuxedos and evening gowns!"), vapid anecdotes ("When I was taught geometry at school") and gauche attempts to sound unpompous ("if you buy into the Nietzschean critique, ask yourself..."). Often, discussions of a topic are so compressed that they are likely to leave a novice mystified rather than enlightened.

The authors attempt to cover too much ground in this book, and fail to cover what they do in a clear and systematic way. I cannot recommend it for students.

Jonathan Lowe is professor of philosophy, University of Durham.