Character Analysis
The Disney version of this story may have made the Archdeacon of Josas evil to the core, but as it turns out, Frollo wasn't always such a bad guy. He has his redeeming moments: he's devoted to his good-for-nothing brother, for example, and he was the one who took pity on little Quasimodo and adopted him.
It makes us all the more uncomfortable, then, when Frollo gets warped into such a thoroughly twisted figure in the novel.
One-Track Mind
Frollo has a hard time letting things go. Case and point: he's obsessed with knowledge, and he takes this obsession so far that it leads him right into superstition and alchemy:
[…] he was forced, if he could not make up his mind to stop where he was, to seek further nourishment for the insatiable cravings of his understanding. The antique symbol of the serpent biting its tail is peculiarly appropriate to science, and it appears that Claude Frollo knew this from experience. (IV.V.4)
Frollo's obsessive nature prepares us for the moment when he goes all-out stalker on Esmeralda. Look at what he says to himself in his cell:
"One fixed idea haunts me and pierces my brain like a red-hot iron." (VII.IV.23)
Then there's this gem, which he says to Esmeralda while she's in prison:
"I kept hearing your song ringing in my ears, kept seeing your feet dancing on my breviary, at night, in my dreams […] When I had seen you twice I wished to see you a thousand times, to have you always in my sight." (VIII.IV.55)
Yep, Frollo has got a certified one-track mind.
But while having goals is great and all, the problem is that Frollo's mono-vision ends up obscuring whatever it was he originally set out to do. It's a classical can't-see-the-woods-for-the-trees situation. His passion in his quest for knowledge, for instance, ends up drawing him away from knowledge and into the pseudo-magic that is alchemy. Likewise, his desire to possess Esmeralda leads him to have her killed.
That's irony, folks.
A Bitter (Not So) Old Man
Frollo might be a rotten apple, but he's also the one who saved the baby Quasimodo when everybody else wanted to throw him on the garbage pile.
If Frollo wasn't always so mean, then what turned him? We're given a few clues, like when we're told in Book IV.V that Frollo's lost the youthful idealism that had compelled him to adopt Jehan and Quasimodo. It seems Frollo had a lot of dreams about the future, and things didn't really turn out the way he thought they would. Now, the dude is disillusioned and prematurely old: the book tells us that "if, as he grew older, gaps opened up in his science, they did in his heart as well" (IV.V.10).
But something else is afoot. Frollo is a gloomy, troubled, and withdrawn person as it is, but we also find out that "[t]hese symptoms of a violent moral preoccupation had acquired an unusual degree of intensity at the period of the events related in this story" (IV.V.11). In other words, something is eating at Frollo. We're next told that Frollo's recently developed an unusual aversion to women and gypsies. Sounds suspicious…
These clues let us know that Frollo is taking out his sexual frustration on Esmeralda. As the story progresses, we get to see a lot more facets to Frollo's emotions, but the real kicker comes after he thinks that the deed is done and Esmeralda is dead. At this point, he goes to the outskirts of Paris to do some serious soul-searching:
And when, while diving into his soul this way, he saw how large a space nature had prepared there from the passions, he laughed still more bitterly. He stirred up from the bottom of his heart all its hatred and its malice, and he perceived, with the cold indifference of a physician examining a patient, that this hatred and this malice were only distorted love; that love, the source of every virtue in man, was transformed into horrid things in the heart of a priest, and that someone constituted as he was, in becoming a priest made himself a demon. (IX.I.4)
All right, Frollo, go ahead and blame the priesthood. Really, though, it sounds like young Frollo once saw the world through rose-colored glasses and is now realizing—too late—that you can't utterly deny yourself something like romantic love without becoming a teensy bit bitter about it.
Now, Quasimodo and Esmeralda are both young characters who are unable to find love—Quasimodo because he's too ugly, Esmeralda because she's too beautiful. Frollo shows us what happens to someone who never gets love, and it ain't pretty. Do you think Quasimodo and Esmeralda would end up like Frollo in fifteen years' time? Would they become bitter and nasty?
We can't say for sure, but one thing we do know: The Hunchback of Notre-Dame shows us how essential love is for everyone.
Frollo's Timeline