Curley and Carlson of John Steinbeck's Of Mice and Men represent the alienated men who become brutish and cruel as a result of their separation from friends and family with whom they can empathize. Alone and among strangers, these men lose the sesitivity that comes with sharing with others. As a socialist, Steinbeck believed deeply in the importance of the brotherhood of man; he felt that left to his own, man becomes heartless, cruel in his fear of others in their lonely vulnerability.
Thus, Steinbeck's motif, the strength to oppress others is itself born of weakness, is again interposed in the final scene that sees the cruel and alienated men, Curley and Carlson, asking what is wrong with Slim and George with ridicule in their tone. They understand nothing of the fraternity of men; they have lost their very souls to the cruel circumstances of the isolated ranch and the alienation of the itinerant worker in the Depression era. They are but brutes; the one always ready to fight, the other ready to shoot old dogs. Much of their humanity has been lost in the mouse maze of life in which they live, going from lonely place to lonely place, whether it be a new location or to lonely home and unfriendly bunkhouse, as is the case with Curley.