Father O'Brien's name on a book usually means a healthy sale, and there is no reason to believe that the present work will do otherwise, particularly since the topic is controversial and timely. Why Priests Leave is a collection of fifteen pieces, twelve of them essays by priests who have left the ministry on why they resigned from the Catholic priesthood. The two most common reasons advanced, as might be expected, were the problem of celibacy and conflict with authority, though other motives--some more straightforward and others less so--are also cited. Some of the pieces are striking and persuasive, while others are faintly redolent of self-indulgence at best and of self-pity at worst. Still, since the purpose of the book is to explain ""why priests leave,"" one may assume that such sentiments are not out of place if one is to see the picture as a whole. O'Brien's own contributions, particularly his appeal for official recognition of clerical marriage, are down-to-earth and convincing presentations of the case for a change in the working concept of the Catholic priesthood.