Churches (Motif)
Much of the novel takes place in and around churches. The prevalence of these structures speaks to the theme of religious hypocrisy in the novel, but also draw on the conflict between appearance and substance. Churches are magnificent buildings, but this beautiful outside might conceal terrible hypocrisy and cruelty.
The Serpent and the Garden (Allegory)
After Ambrosio tells Matilda that he must move her to another convent, she asks him for a token of his affection to carry with her. He reaches down to pluck a rose, but a serpent bites him and he nearly dies from poison (an opportunity that Matilda uses to seduce him).
The motif of a beautiful, tempting woman and a snake in a garden is reminiscent of the Garden of Eden story in Genesis, in which Eve is tempted by a serpent to eat the forbidden fruit. Eve then offers this fruit to Adam, and God punishes the two by expelling them from the garden and sentencing all their descendants to hard labor. In the novel, the scene with Matilda and the serpent is another example in which a woman tempts a man to go against God's laws, with utterly disastrous consequences for everyone involved.
Ghosts (Motif)
Ghosts make frequent appearances in The Monk. The Bleeding Nun is first introduced as a mere story by Agnes, but later this ghost takes on terrifying reality and haunts Raymond. Elvira appears to Antonia on a dark and lonely night, warning her daughter that she will join her in three days.
The ghosts in the novel share the similarity of being murdered unjustly, and seeking to address that wrong. They also add to the atmosphere of foreboding that characterizes gothic fiction.
Crypts (Symbol)
Matilda summons demons in the crypts, and both Agnes and Antonia are imprisoned in this same place. Entry into the crypts represents contact with the underworld. Filled with moldering dead bodies and located deep underground, the crypts bring one into contact with the dead and with demons; they also force each person to face what he or she dreads most. In the case of Ambrosio, this is the pact he makes with demons; for Antonia, it is Ambrosio's horrendous betrayal; for Agnes, it is the death of her child and her total isolation from society. However, it is also possible for people to emerge from this hellish experience - Agnes is eventually freed and goes on to enjoy a happy life.
Myrtle (Symbol)
In order to assist Ambrosio in his mission of possessing Antonia, Matilda summons a demon that gives the monk a sprig of myrtle (pg. 293). This magical myrtle opens the locked doors to Antonia's home, and when placed under her pillow, puts the young woman into a deep slumber.
In both the ancient Mediterranean and in eighteenth-century England, myrtle was a symbol of love and marriage. In the novel, this meaning is twisted and distorted - myrtle becomes the symbol of the wicked monk's desire to sexually possess an innocent young woman.