We all grow up incessantly asking our parents, teachers and peers ‘why’, ‘what’ and ‘how’. Some people never stop. In the illuminating and very readable A Little History of Philosophy, Nigel Warburton tells us about 40 of the most special questioners and their key ideas, taking us on a rip-roaring journey through the history of Western philosophy. The questions are timeless – How do I know what’s real? Is it ever right to lie? Why should I care about others? What does it mean to be free? – and also of urgent importance to the way we live now: How should we treat animals? Can computers ever be intelligent? What do we owe to poorer people in far-off lands?

One of the ways philosophers consider the knottiest ethical problems is by using thought experiments. One of the most famous is about a runaway train – explored in Chapter 37. Imagine that you see it one day hurtling out-of-control down the tracks towards five workers. It’s going far too fast for them to get out of the way in time, and they will surely die. However, there is a fork in the tracks just before the men. On the other line there is one worker who would get squashed. You are close enough to the points to flick the switch and divert the train. Should you?

There is no right or wrong answer – some think it’s right that one should die instead of five; others say it’s wrong to ‘play God’ and divert the train – but a good life is one in which we ask ourselves these sorts of questions. A Little History of Philosophy is an enlightening, witty book, that will help you to do so too.