Throughout the course of Steinbeck's Of Mice and Men, the author examines the concepts of lonliness and isolation. The two main characters, George and Lennie, do not have wives, but they do have each other. They travel around together, they work together, and they share a common dream of buying a little house and running a small farm.
Besides George and Lennie, Steinbeck's audience also meets characters like Candy, whose best companion is an old dog that Carlson shoots to put out of its misery. Once Candy becomes isolated, he tries to buy in (literally) to George and Lennie's dream house to avoid experiencing further isolation and lonliness.
Steinbeck also present us with a character named Slim. Slim has been married for two weeks, but already his wife has eyes for other men. So, even though, she is married, she seems to be quite lonely.
Thus, in the course of his novel, Steinbeck seems to be saying that people need each other. They need the society of other people. They need to feel valuable and needed. Furthermore, conventional relationships, such as husband and wife, provide no guarantee that a person will not be lonely. On the other hand, unconventional relationships, such as the one between George and Lennie, the latter of whom is mentally challenged, can be deep and meaningful.
George said, “Guys like us got no fambly. They make a little stake an’ then they blow it in. They ain’t got nobody in the worl’ that gives a hoot in hell about ‘em—”
“But not us,” Lennie cried happily. “Tell about us now.”
George was quiet for a moment. “But not us,” he said.
“Because I got you an’—”
“An’ I got you. We got each other, that’s what, that gives a hoot in hell about us,” Lennie cried in triumph.