Molly Graham represents the Greek goddess, Aphrodite.
It's time to nail down the familial relationship between Dr. Bloom and Molly. We know that our Molly corresponds, at least in name, to the Molly Bloom character from James Joyce's novel, Ulysses, so, noting that she and the doctor appear to be close to each other in age, she is either his sister or his cousin. Dr. Bloom represents the Greek god, Dionysos (also spelled 'Dionysus'). Dionysus was the son of Zeus and Semele. Molly represents Aphrodite, the Greek goddess of love, beauty and sexuality. This is what is being intimated by the close-up we get of her in Will's dream, in which she is wearing white clothing and sandals - the camera dwells on her, as if to emphasize her beauty and sexuality (see the screencap above).
In Homer's Iliad, Aphrodite is the daughter of Zeus and Dione. Noting that Dionysus and Aphrodite have the same father, Zeus, but not the same mother, we conclude that Dr. Bloom and Molly are half-siblings. Thus, their marriage was an incestuous one. As we might have guessed, St. Augustine has something to say on marriage between relatives. From Book 15, chapter 16 of City of God:
Of marriage between-blood relations, in regard to which the present law could not bind the men of the earliest ages
As, therefore, the human race, subsequently to the first marriage of the man who was made of dust, and his wife who was made out of his side, required the union of males and females in order that it might multiply, and as there were no human beings except those who had been born of these two, men took their sisters for wives - an act which was as certainly dictated by necessity in these ancient days as afterwards it was condemned by the prohibitions of religion...
And we see that, since the human race has increased and multiplied, this is so strictly observed even among the profane worshipers of many and false gods, that though their laws perversely allow a brother to marry his sister,[a] yet custom, with a finer morality, prefers to forego this license; and though it was quite allowable in the earliest ages of the human race to marry one's sister, it is now abhorred as a thing which no circumstances could justify.
For custom has very great power either to attract or to shock human feeling. And in this matter, while it restrains concupiscence within due bounds, the man who neglects and disobeys it is justly branded as abominable. For if it is iniquitous to plough beyond one's own boundaries through the greed of gain, is it not much more iniquitous to transgress the recognized boundaries of morals through sexual lust?
a. This was allowed by the Egyptians and the Athenians, but never by the Romans.
City of God (Dods)
