There is great, though, as it turns out, pointless, irony in the fact that the litterateur A. N. Wilson penned this life of a famous Christian apologist while he was in the process of giving up his own Christian faith. One might anticipate from such a juxtaposition some unusual insight into Lewis' (in this case unsuccessful) methods of argumentation. Alas, nothing of the sort occurs. This is simply another Lewis biography, following the familiar outline laid down by Lewis' own "Surprised by Joy" and adding very little, save for catty psychological guesswork, that has not appeared in earlier productions of the prolific Lewis "industry".
The book's great sensation is the assertion that the young Lewis, at around age 20, had an affair with Mrs. Jane Moore, the woman whom he "adopted" as a mother figure for the rest of his life. The theory, borrowed without acknowledgement from the eccentric American Lewis scholar Kathryn Lindskoog (whom Wilson repays with unfair derision), lacks both plausibility and evidence. Lewis had lost his mother at a young age and had chafed under his father's well-meant but wrong-headed tutelage. Mrs. Moore's son, for a while Lewis' closest friend, had died in the Great War. That the two should have formed a substitute family is not at all surprising. Wilson offers no grounds for supposing that the relationship was sexual. Instead, he offers "evidence" of this sort: Lewis' diaries use the Greek letter delta (our "D") as shorthand for Mrs. Moore. Of the many Greek words and names beginning with that letter, he singles out "Diotimia", from whom the Socrates of Plato's "Symposium" is supposed to have learned his theories about eros. That is just a wild guess, evidently made without knowledge of the fact that delta is the first letter of the Greek transliteration of "Jane". (Our "j" sound is not native to the Greek language but can be represented by the diphthong delta-zeta.)
Wilson's major weakness as a biographer is... his incurious, intellectually lazy approach to a field already tilled by many predecessors. A life that looked at Lewis from a different angle, that, for instance, probed his pre-Christian philosophical opinions and asked to what extent they truly changed as a result of his conversion or that placed his apologetics next to the works (Wells, Huxley, Bergson, Teilhard de Chardin et al.) against which he was reacting or that gave adequate attention to his professional literary interests, could have been a fresh and vivid portrait. One that accepts prior interpretations with a few unflattering twists is not.
There is no point in writing a biography simply in order to say what has been said before - not even if one says it with slightly more elegance and now and then taxes the subject for his failure to anticipate politically correct points of view. As a compendium of bare facts, sprinkled with factoids, Wilson's book is acceptable, but it is hard to imagine a reason for anybody to seek it out.