This story explores the isolating effects of mental illness. Seymour Glass, a troubled young man just back from service in World War II, has difficulty adjusting to being home, no doubt as a result of his experiences in the war. In some ways Seymour self-isolates, but in other ways he is alienated by "normal" society that doesn't understand his mental condition. This isolation is physical, mental, and spiritual – Seymour finds himself "alone" in more ways than one.
Salinger portrays Seymour as superior to the other materialistic adults in his story.