What are the motifs in The Iceman Cometh by Eugene O'Neill?

Isolation is a recurring idea in the play. The characters in The Icema Cometh are isolated from mainstream society. This is evident from the beginning, when the curtain opens on the drunken, sleeping men alone in the literal world of their dreams. As the play progresses, the essential isolation of the characters becomes clear. Even awake, each character remains caught in his or her own dream. There is a sort of camaraderie among O'Neill's roomers, but this small sense of community is revealed as a thin veneer following Hickey's arrival; his proclamations of false dreams reveal an underlying animosity. Forced to face their hopeless realities, the roomers fight among themselves until Hickey's departure allows them to return to their pipe dreams.