It took me the entire book, I'm embarrassed to say, to realize that the story was not about Reuven's journey so much as Danny's journey. It is the fact that Reuven does not understand the ways of Danny's people or the methods of Danny's father that make the story really about him.
Reb Saunders, Danny's father, chose to rear Danny in silence. They never spoke unless they were studying Talmud. Rabbi Saunders's goal was to guide his son to find his soul. The only way to discover one's soul is through inner reflection. This statement I can sort-of agree with; in high school I realized my Self through a few years of self-imposed silence. Between that and the philosophical reading I've done since I'm pretty aware of my Self (no, the separation of the two words is not a mistake). I think that is what Reb Saunders wanted for his son, not only to understand the great gift of mind that he'd been given, but to also know his Self so he could better serve his people.
Even Reb Saunders makes a journey through the novel. He is aware that he closes himself off to the world, justifying it by not wanting to be tainted by the outside. When Reuven's father makes a big deal of the need for a Jewish state, Saunders tells Danny he and Reuven are not allowed to see each other anymore. Once Israel is established, the boys renew their friendship. Reb Saunders asks after Reuven. Saunders speaks to his son through Reuven, which I thought was an interesting way to do things, though I do not understand. Saunders uses Reuven to tell Danny that he can become a psychologist. He uses Reuven to tell Danny that "All his life he will be tzaddik. He will be a tzaddik for the world. And the world needs a tzaddik" (287). Saunders has realized the good his son can do for not only his people, but for people outside the Hasidim as well.
What we see here is more of the evolution of religious ideas. The evolution of ideas, like the evolution of any living creature is a slow process. By suggesting that the world could use Danny's mind, we see a tzaddik looking at his son with more than the eyes of his people. With this openness, maybe more tzaddik will be able to affect change and encounter less opposition.
Potok, Chaim. The Chosen. New York: Ballantine Books, 1967.