George's taking care of Lennie and the dream of the farm are attempts to break the pattern of loneliness that is part of the human condition. Similarly, Lennie's desire to pet soft things comes from his need to feel safe and secure, to touch something that gives him that feeling of not being alone in the world. For Lennie, the dream of the farm parallels that security.
George and Lennie, however, are not the only characters who struggle against loneliness. Although present in all the characters to some degree, the theme of loneliness is most notably present in Candy, Crooks, and Curley's wife. They all fight against their isolation in whatever way they can. Until its death, Candy's dog stopped Candy from being alone in the world. After its death, Candy struggles against loneliness by sharing in George and Lennie's dream. Curley's wife is also lonely; she is the only female on the ranch, and her husband has forbidden anyone to talk with her. She combats her loneliness by flirting with the ranch hands. Crooks is isolated because of his skin color. As the only black man on the ranch, he is not allowed into the bunkhouse with the others, and he does not associate with them. He combats his loneliness with books and his work, but even he realizes that these things are no substitute for human companionship.
Steinbeck reinforces the theme of loneliness in subtle and not so subtle ways. In the vicinity of the ranch, for example, is the town of Soledad. The town's name, not accidentally, means "solitude" or "alone." Also, the others' reactions to George and Lennie traveling together reinforces that, in Steinbeck's world, traveling with someone else is unusual. When George and Lennie arrive at the ranch, four other characters — the boss, Candy, Crooks, and Slim — all comment on the suspicious nature of two guys traveling together. This companionship seems strange and, according to at least the boss and Curley, the relationship is sexual or exploitative financially.