It’s easy for a very short guide to a subject to become a collection of information without narrative or style. Luckily Lawrence Principe’s entry in the OUP pocket guide series is the very reverse. It is elegantly written and fascinating to read. Along the way you may well have your illusions about the history of science shattered. Nothing much happened in science between the Greeks and the renaissance? Wrong. They thought the Earth was flat in Columbus’s day? Wrong. Galileo’s trial was all about science versus the church? Wrong. What comes across most strongly – and it’s why I’ve always found medieval science absolutely fascinating – is that you have to see the world with a different mindset. It’s not that they were all illogical and stupid back then, merely that they started from different first principles and built logically but incorrectly on these. This little book gives an excellent feeling for where our scientific ideas came from, how the approach to science was shaped by