The Jesus Prayer
The crux of Franny and Zooey is the Jesus Prayer Franny takes from the religious "Pilgrim" books. By incessantly praying to Jesus, the person who prays is endowed with "Christ-Consciousness," in Zooey's words, and can see God, in Franny's words. What Franny realizes only at the end of the novel, thanks to Zooey's wisdom, is that not only does one unite with Jesus through the prayer, but through all humanity, since everyone carries Christ within him or herself. The Jesus Prayer has more to do with love than with religion, as incessant praying spans several religions.
The Fat Lady
The point of the Jesus Prayer, that all humans deserve love and respect if only for their very humanity, is embodied in the persona of the "Fat Lady," Seymour's name for the (what Franny and Zooey perceive to be) uneducated, unattractive fans of "It's a Wise Child." Ultimately, we can see the Fat Lady symbolized as Bessie - Zooey even calls her "fat" several times - who is far below her children in terms of intelligence, but still deserves their respect and love. Respect was Franny's original deficit - she told Lane she was sick of liking people and wished "to God I could meet somebody I could respect." By literally doing this - praying to Jesus - she learns respect for those she has already met. We may assume that Zooey, who has a far more hostile relationship with Bessie, will come to this conclusion, as well.
Zen and the Art of No-Knowledge
The novel is peppered with Zen Buddhist ideas, largely centering around the concept of "no-knowledge." The Buddhist must clear his head of preconceived ideas in order to attain wisdom. This process counters Western education, which crams its students with knowledge - Franny complains that the poets at her school don't leave anything beautiful on the page, but only get into your head. She is upset at herself, as well, for trying to hoard wisdom through the Jesus Prayer as others hoard knowledge. True "no-knowledge," by its very absence, cannot be hoarded.
Ego, Detachment, and Destruction
The path to Buddhist "no-knowledge" is detachment, the letting go of one's personal ego and selfish concerns to attain enlightened beauty. Why does Franny rail against the section men and her professors? They are competitively absorbed in their own egos, and whatever detachment they have is detachment from humanity. As such, they lead insecure lives of critical destruction - the section men ruin literature for others, Lane is interested only in his critical paper on Flaubert. Buddhist detachment rids oneself of the negativity of ego and frees up the positive part of the ego: Zooey tells Franny she must act, as that is her God-given talent, and use her ego as best she can (much as Buddy counseled him to do). But she must not let the negative part of the ego interfere - by making her criticize her fellow actors, for instance. Instead, she must focus only on her own art, and do the best she can. While this seems like an inherently egotistical practice, it is the only way an artist can ensure purity, and ultimately the art is in service of others. Seymour's diary entry, describing his family's selfless performances for him on his birthday, is a good example of this positive use of ego.
Critique of Conformist Bourgeois Culture
Salinger launches an all-out critique against American bourgeois (middle- and upper-class) culture. The 1950s are noted for being a time of great conformity, and Franny is upset over everyone's desire to be alike. She also points out that those who rebel are just as conformist. Lane, especially, is the poster boy of bourgeois conformity; he believes he is different from everyone else, but he dearly craves acceptance. Salinger exposes a few symptoms and causes of the obsession with conformity. The cult of celebrity is a major feature in the lives of the Glass children, especially Franny and Zooey, who are still performers. While nearly everyone strives to be a celebrity, or stand out, celebrity only deforms the Glasses. The public reveres them as prodigies or loathes them as smart-alecks, but either way, they are not normal - they are "freaks," as Zooey says. What the culture of celebrity produces artistically, however, is conformist entertainment. Zooey mercilessly criticizes television, and those who work in it, for turning all stories into pat, sentimental fairy tales that please the masses. Finally, Salinger derides psychoanalysis, which started to gain mainstream popularity after WWII, as a misguided exercise of normalization, a tool to make everyone the same.
Egotism and authority of "Zooey"
Buddy Glass, narrator of "Zooey," admits that his writing suffers from being too "clever," and at times his ornate writing style is difficult to swallow. Compounding his problems with ego are J.D. Salinger's himself, as there are numerous similarities between Buddy and Salinger: both are students of Zen, both have been writing stories since they were 15, both live in remote rustic cabins. However, Buddy says that "Zooey" is a collaborative effort; he has culled his narrative from the separate stories of Franny, Zooey, and Bessie. In this sense, the egotism of "Zooey" is diffused; there is no single author, but five (including Salinger). In the same vein, Zooey's advice to Franny at the end of the novel is also a product of diffused ego. He gives her the advice while in Seymour and Buddy's old room, inspired by his brothers and their quotes of wise men on the wall. He loses his own ego - so present in his face-to-face talk with Franny - and shares it with others, just as Salinger shares it with Buddy and the Glass Children.
"Glass" symbolism
The Glass surname has a number of meanings. Glass is invisible, and though the Glass children store away many secrets (Buddy, especially, seems to know more about Seymour's suicide than he lets on), they also lack privacy - Bessie is constantly barging in on Zooey, and Buddy has gone so far as to not install a phone in his house. Glass is also reflective; self-aware prodigies, they are all victims of their own egos and narcissism, especially Franny and Zooey, who are physically beautiful to boot. Finally, glasses are receptacles that hold liquid. In a practical sense, the Glass children hold and store everything that comes their way, soaking it all in. Glasses also hold water, and water is an important association with Zooey, who bathes, shaves, sweats, used to have fish, and even steps on a newspaper picture of a fish. In a possible mythological reference, Salinger may be portraying Zooey as the Fisher King, the savior who would deliver humanity from a dry, barren death.