The Imitation of Christ has been translated into more languages than any Christian book except the Bible, and its manner is the reverse of impressive. It is short, plain, addressed to one reader, and openly suspicious of learning: it would rather feel compunction, it says, than be able to define it, and asks what use it is to argue profoundly about the Trinity if you lack humility and so displease the Trinity. Four books move from general counsel through interior life to a long meditation on communion.
Its severity is real and is why it has both attracted and repelled. It counsels withdrawal, distrust of company and of one's own judgement, and the expectation of consolation withdrawn. It has been the daily book of an enormous range of readers who otherwise had nothing in common.
The authorship has been argued for six centuries. Thomas's claim rests on a manuscript in his own hand signed and dated 1441, which is strong evidence and not decisive, since a copyist's autograph proves he copied it. The French and Italian traditions long attributed it to the chancellor Jean Gerson, and a serious case has been made for Gerard Groote himself, partly on the argument that an underlying Middle Dutch rhythmic text lies beneath the Latin. The majority position remains that Thomas wrote it, out of the movement's common stock of material, and the atlas records the attribution as contested rather than settled.