Using The Glass Menagerie by Tennessee Williams and the symbol of the gentleman caller, explain how this symbol gives insight into one of the main characters and how Williams uses this symbol to reinforce a meaning in the work.
In the first scene of The Glass Menagerie by Tennessee Williams, Tom Wingfield (as the narrator) tells us that we are going to meet what turns out to be the only non-Wingfield character in the play. Jim is the gentleman caller, and Tom says he is symbolic of
the long delayed but always expected something that we live for.
Of course, Tom is a self-confessed poet who has an affinity for symbols, so we are not surprised that he sees things symbolically. In the same scene, however, Tom also says that Jim is
the most realistic character in the play, being an emissary from a world of reality that we were somehow set apart from.
Tom is actually correct on both accounts, but the description is incomplete.
You ask about how Jim gives insight into one of the characters, and the most obvious person in that regard is Laura. On a real level, we learn some truths about Laura that we might have suspected but now we know are true.
Laura thinks her "slight defect" is a loud, noticeable thumping every time she walks. We learn now that in high school she did have a slight limp but nothing as outrageously noticeable as Laura believes. The fact that she is shy is confirmed, of course, but we no know that most of the insecurities which have kept her from truly living her life are more imagined than real.
Because Laura has turned inward, her life has gotten very small, In fact, her life is centered around and symbolized by a small collection of glass figures which is the "glass menagerie" to which the title refers. Her favorite piece in the collection is a fragile glass unicorn, an obvious representation of her own life.
The unicorn is so fragile that Laura says:
If you breathe, it breaks!
Laura is not made of glass, of course, but she is delicate and almost unearthly, like a glass figurine. Laura is not an actual unicorn, but she is, like the mythical creature, unique because she is not like others.
When Jim arrives, he has to work in order to get Laura to even talk to him. Eventually he gets her to dance with him, and when they do the glass unicorn's distinctive horn is broken. While Jim may not recognize the symbolism of this moment, but both Laura and the audience do. Laura even calls it a "blessing in disguise."
So Jim is the symbol of "the long delayed but always expected something that we live for," and his appearance brings something very important insight into Laura: a new reality, which gives her (and us) hope for her future. Now she is, symbolically, just a horse like everyone else.
Jim does represent the reality that the Wingfields seem to be excluded from, as Tom suggested. He has plans, goals and dreams which he has taken action to achieve. That makes him much different than any of the Wingfields who have hopes and dreams but have virtually no insight or plan to make them happen.
On the other hand, Jim can also be seen as a symbol of the same disillusionment from which the Wingfields suffer. While he talks confidently (and constantly) about his own hopes and dreams, like the Wingfields he has made little actual progress toward achieving them. He works the warehouse with Tom and has convinced himself that the world to come will be better than the present (which we know is not true in the short run because of economic depression and a looming war). His arrival was supposed to be Laura's escape; instead, he represents another shattered illusion in the Wingfields' lives.
Jim "makes" Laura a "real" girl, but he also reinforces the theme of unfulfilled dreams.