The Printing Press
Referred to as German pest, the revolutionary press invented by Johannes Gutenberg is viewed with everything from suspicion to dread by those already in positions of power or authority. Frollo has served the church long enough to recognize that control over knowledge and with whom it is shared is the most powerful weapon in the world. He couches his argument in elitist terms as those desperately trying to keep ignorance of the masses intact always do, but once invented, intellectual superiority would inevitably fall victim to the demands of the masses to share in the light. The printing press thus takes on symbolic value beyond mere power to print words, but to disseminate information and sow the seeds of the truly sweeping changes about rush over all of Europe and put an end to petty tyrants like Frollo on its way to sweeping aside much bigger game.
Esmeralda's Red Baby Shoes
The Gypsies—ironically, considering the bad representation they get in most fiction—are the agents of Esmeralda’s virtue and purity. They sold the young girl on the idea that as the one red shoe in her possess is a powerful totem of virtue and that as long as she protects the shoe, her sexual innocence will remain intact. Seems to work since the beautiful young woman seems to be second only to Quasimodo himself in terms of goodness.
Spider and Fly
You know these two creatures have to be taken symbolically because Frollo just won’t let it go. As he intently observes the process of spider laying a trap for a fly, it only makes sense that he would see himself as the fly caught in the web of lust that is coming back to devour him after rejecting and denying natural urges for so long. Likewise, the object of his lust can be seen as personification of a fly trapped within the complex legal web of the church. Where it gets kind of weirdly philosophical, however, is his associational editing that links the spider to the printing press and the fly to Notre Dame. Kind of a stretch, but then Frollo is kind of a strange bird.
The Cathedral
The very title indicates that the Notre Dame cathedral is meant to be taken as a symbol as well a literally concrete structure. Quasimodo is so attuned to the vibrations of the building since he cannot hear that he views it as a living organism. The symbolic value of the cathedral lends it an appropriate status as one of the three parts of the trinity of purity and innocence, alongside the hunchback and the Gypsy girl. When he learns that Frollo has corrupted both Esmeralda and Notre Dame by making it a sanctuary for his unholy lust and black magic Quasimodo tosses him through the air so that Frollo literally falls from the grace that is the cathedral’s masonry.
