How many more books do we need on the causes of the recent financial crisis? Wordage on that theme seems as capable of infinite expansion as, say, trading volumes of complex derivative instruments in global securities markets. In both cases, the crucial question to ask is whether more is better – and the answer in general is almost certainly not.

Yet I would suggest that even on the most overcrowded bookshelf we should find space for the wisdom and humanity of John Kay. A Financial Times columnist and non-executive director of several public companies, as well as an Oxford and LSE economist and a prolific author, Kay is billed as an ‘industry insider’. In previous books, such as The Truth about Markets (2003), he has made plain – in contrast to the likes of Will Hutton, who sermonise on the subject of finance as disapproving outsiders – that he is by no means hostile to the idea of capitalism as the great engine of prosperity, so long as it is set in a