"The heart is half a prophet."—Yiddish Proverb
The epigraph isn't specific to the novella Goodbye, Columbus but shared with the other stories in the collection. It prepares us for the intensely emotional tone and themes of love that infuse all the stories. For Goodbye, Columbus specifically, it comments on Neil's constant self-reflection and self-analysis. Even though he is often blind to Brenda's needs, his does look inward to try to find out how he feels about her. He looks to his heart to prophesize or disclose the truth of what he wants and what he should do with his life.
But, his heart is only half a prophet. Feelings are discovered, and feelings change as life goes by. The heart doesn't know everything in advance. We can also think of Neil's heart as torn in half during his relationship with Brenda. He loves her, but feels as if being with her makes him disloyal to and separated from Newark—where his heart is.
Neil is also conflicted about his work as a librarian. His flirtation with a job at Patimkin Sinks is another way his heart can be seen as torn in half during much of the story. We might also ask the question: if the heart is half a prophet, what is it on the other half? Hunger? The cosmos? Cookie Monster?
Goodbye, Columbus is heavy on foreshadowing, which is a lot like prophecy. The novella also has many prophetic-sounding statements, as well as some allusions to prophecy. Perhaps the first allusion to prophecy is connected to Ron. When Neil first sees him at the Green Lane Country Club pool, he thinks he's "like a crew-cut Proteus rising from the sea" (2.55). In Homer's The Odyssey, Proteus is a sea god who:
Will foretell the future to those who can seize him, but when caught he rapidly assumes all possible varying forms to avoid prophesying. When held fast despite his struggles, he will assume his usual form of an old man and tell the future. (source)
Now, it's quite possible that Roth was evoking Proteus to let us know that Ron is really big and almost divinely perfect, in terms of looks and stamina. Other than playing the "Columbus record" (5.51), which could be considered prophetic (see "What's Up With the Title?"), there is nothing to indicate that Ron is a shape-shifting prophet. But when Neil sees Ron at his first day of work at Patimkin Sinks, he sees what his own life might be like if he stays with Brenda. So, Ron could be considered a kind of inadvertent prophet, or a symbolic prophet. Unlike Proteus, Ron seems to be unaware of his role. Hey, ignorance is bliss.
The most obvious early example of prophecy is when the boy says to Neil:
The heart section. Ain't you got no heart section? (3.10)
This could be seen as a prophecy of Neil's search for his own personal heart section, the place his heart belongs. This question of where his heart belongs is crucial to Neil and drives the entire story. As with Ron, the boy doesn't seem aware of this role as prophet, or how important he is to Neil.