C S Lewis attracted so reverential a following that practically all his literary remains have now been seen into print, though the final contributions contain much of indifferent quality that does little service to his memory. Various groups of his letters have been published and the diary he kept – with many long gaps – between 1922 and 1927 must be the only substantial unedited manuscript that has not yet received editorial attention. It will be of particular interest to biographers of the days before that celebrated moment in 1929 when ‘the most dejected and reluctant convert in all England’ knelt in submission to the realisation that ‘God is God’.

A N Wilson used the diary in his excellent life of Lewis, but the infrequency of his quotations hints that it is less lucrative a source than its bulk might suggest. Here are over four hundred pages of text, plus appendices and other apparatus, printing some two-thirds of the original.