Graham Greene is a writer who, like Fëdor Dostoevski, has lived his life under the torment of faith. When the priestly Alyosha Karamazov kisses his brother, the skeptical Ivan, at the end of the Grand Inquisitor chapter of The Brothers Karamazov, Dostoevski mediated, in Ivan's--and in his own--search for meaning, in favor of God. In his world, in which evil dominates, Greene takes a good-bad man and puts him in a situation where his potentials for evil and good inevitably collide, where what is at stake transcends integrity. If the character is really good while seeming bad, nothing will serve him better than his vulnerability. Greene paves hell with heavenly intimations until, finally, innocence--that is, freedom from a controlling guile or cunning--takes over everything, even corruption, and a state that Greene calls grace is reached. In Greene's major novels, the protagonist's fall is always fortunate because...