The historical profession lives by gloomy maxims – not surprisingly, since its business is human nature – and one of the gloomiest is that the road to Hell is paved with good intentions. That could form the epigraph of John Cornwell’s passionate and engrossing study of the rite of sacramental confession in the history of the Catholic Church. At the centre of it all is one of the most powerful ideas in the Christian tradition, that a priest has the capacity to pronounce God’s forgiveness of sin, around which the industry of confession revolves. Forgiveness, surely, is a good idea. But then comes another: a papal call to holiness for Catholic clergy, by forcing all of them, monks and non-monks alike, into a profession of celibacy. That project began in the 11th century and while it never eliminated de facto clerical marriage in the medieval period, it certainly degraded such unions; one strong impulse in the Protestant Reformation was to reverse this landmark policy. A third good intention was the binding of the laity to a regime of individual confession to a priest, at least once a year. This was one requirement demanded by a very busy council of the Church held at the