‘Read with care and precision, dear reader, and you will marvel and will not be sorry.’ So advises a Latin note scribbled in 1550 by a Benedictine monk into his copy of Cornelius Agrippa’s De occulta philosophia (1533), a book promising full reform of the ‘sublime and sacred science’ of magic. Alas, not everyone was so enthusiastic: Agrippa’s book was condemned as heretical by the inquisitor of Cologne. 

At the same time, it received approbation from the city’s archbishop. The place of magic in Renaissance Europe was much contested. So was its definition. Today, every child who has read the Harry Potter books will have a sense of what its components should be. But even here there are ambiguities. After all, Hogwarts students must study astronomy, which seemingly has no magical content. Agrippa himself expressed an ambivalent attitude when, in the final chapters of his book, he condemned as superstitious (or worse) many of the magical practices he had previously discussed. ‘The art of occult philosophy is refuted and rejected by its own inventor. Well, then, farewell to it, in the name of the devils’, our Benedictine dutifully noted in the margin.

Anthony Grafton has plunged himself into this cauldron of ambiguities in his scholarly but marvellously readable Magus. The study of Renaissance magic has a long history. Predictably, many have dismissed it as charlatanry or self-delusion. Others have found in it nothing less than the origins of modern science. Grafton is too careful a scholar to subscribe to such grand generalisations or to present an essentialised ‘Renaissance magic’. Instead, he follows the trail of evidence in an attempt to recover the mental world of the 16th-century magus in all its bewildering and bewitching complexity. 

Like all the best historians of the Renaissance, Grafton knows that none of its aspects emerged suddenly upon the wave of an intellectual wand. Accordingly, he begins by charting the late medieval debate about magic. By the 14th century, astrology had become central to the European system of knowledge. It