What does it mean to know something? Headache acquired.

Never fear, your panadol is A Dictionary of Philosophy, as it approaches these questions through the accumulated vocabulary of philosophical inquiry, assembling definitions, intellectual histories, arguments and competing interpretations into an unusually navigable reference work.

Spanning ancient philosophy to twentieth-century debates, its entries move between metaphysics, epistemology, ethics, aesthetics, logic and the philosophy of language, alongside questions arising from psychology, religion, mathematics and science. Entries on interpretation, intentionality, personal identity and moral responsibility demonstrate how even apparently straightforward definitions conceal centuries of argument.

There is something rather satisfying about philosophy arranged alphabetically. These are thinkers who might never willingly share a room find themselves occupying adjacent columns. A useful companion for students and independent readers, but equally suited to the pleasure of opening at random and discovering that an apparently settled word is anything but.

Pan Books, London, 1984. Second revised edition (1983), Pan paperback edition. Blue illustrated wrappers with light surface scuffing, edgewear and minor marks. Pages show some age-toning; internally clean and legible.