Warm, sensitive, creative, outgoing, cheeky, creepy. Scan any personal ads page and it's clear that to get a life you need a personality first. It is also a notion with a long and often bizarre history: in early Greece and medieval Europe, it was thought to depend on the balance of bile in the body.

On Personality is a thoughtful and stimulating look under the skin of this widely-used but little understood phenomenon. Peter Goldie points out that we rely on personality to do a lot of work: describe, judge, understand, explain and predict others as well as ourselves. Is it really up to this task? If personality is about 'character', is it a relic of a bygone Victorian age? If personality is so reliable, how can a virtue in one person be a vice in another?

Drawing on a great range of philosophers, novelists and films, from Aristotle, Hume, Kant and Nietzsche to Joseph Conrad, Middlemarch, War and Peace and Bridget Jones' Diary, Peter Goldie also discusses some famous psychology experiments. If personality is a reliable guide to predicting what people will do, he reflects on why people often surprise us and asks whether personality is simply down to chance and circumstance.

On Personality is essential reading for anyone interested in this fascinating but slippery concept. It will also make you think twice before writing your CV.