Although the priest does terrible things in the novel, one is never convinced that he is a total villain. Hugo obviously intended him as a villain, but, psychologically and philosophically, he was not sold on the idea. This conflict between Hugo's conscious convictions and his deepest, subconscious view of life shows in his style.
If Hugo's full conviction had been that the priest's passion is evil, the priest's way of speaking of his passion would have been much less attractive. He would have projected something ugly or sadistic—a perverted or evil feeling. But instead he speaks of his love in so romantic a way—the examples selected are so glowing and beautiful—that the reader necessarily feels sympathy for him (and so does the author).
In this passage, there are no exalted sentences in defense of religion. When the priest mentions religion, it is always in a blasphemous manner. In this particular projection, religion means nothing to him; he wants to put God under the girl's feet—which is wonderful, but not the way to project an evil passion.
If Hugo's own viewpoint had been what it ostensibly is—if he had really considered the priest a villain for his conflict—he would have presented the passion less attractively and religion more forcefully. But Hugo's subconscious is so much on the side of love and of this earth that I say: "May his God help him!"
Throughout the novel, the priest keeps announcing that his passion is "fate." In fact, earlier in his speech to the girl, he states that he lost the battle against temptation because God did not give to man a power as strong as the devil's. This is a deterministic premise. But what an author might have his characters say, or even what his own stated philosophy might be, is an issue totally different from what his actual, subconscious premises are—as this speech illustrates.
The speech expresses a violence of emotion that can come only from the possibility of choice. An automaton does not experience violent emotions. In literature written on the determinist premise, emotions of pain can be convincingly portrayed, but never a violent passion for a specific object on earth.
Observe the priest's self-assertion. He constantly tells how he tried to fight his passion; then, when he felt the desire to see the girl again, he watched and waited for her. He constantly talks about what he did; and he is begging her to have pity on him, by which he means: consent to love him. He is acting on his passion. He has decided that he cannot fight it any longer, so now he will try to win her. And his emotional violence has one purpose: "If I can convince her of the greatness of my love, then maybe I can win her." This is a man in charge of his own destiny.
If a man in a Naturalistic novel has a passion he cannot resist, there is an enormous tone of whining, amounting to: "Poor little me, I couldn't help it." Here, although the priest uses begging terms like have pity on me and mercy, his tone is not one of complaint.
The Art of Fiction, Ayn Rand, p. 101 - 102