"Who would be so base," asks Christopher Hitchens, "as to pick on a wizened, shrivelled old lady, well stricken in years, who has consecrated her whole life to the needy and destitute?"

The answer is Hitchens himself, in this provocative study of the life of Mother Teresa of Calcutta. He presents a marvellous case, debunking the myth of Mother Teresa as simply as one might peel layers from an onion, producing some old and quite a lot of new evidence to suggest that Mother Teresa, the global icon of sainthood, needs fresh examination in a light unclouded by sentiment.

Mother Teresa's shining reputation, argues Hitchens, has been foist upon her by the millions who need to feel that someone somewhere, is doing the things that they are not to help the poor. She feeds on it, has come to accept and expect it. Now it walks immediately before her, is as recognisable as the blue and white striped sari and veil of her order: no one, least of all Mother Teresa herself, can see past it.

Hitchens has set out to reverse the process...