John Steinbeck, the author of “Of Mice And Men”, is trying to say that the loneliness leads to depression and it is a major theme in the novel. Most of the characters are very lonely because they have no family. However, George and Lennie are the contradiction to this. George and Lennie’s bond towards each other is strong. The theme of loneliness is introduced through the minor characters on the farm. One of the characters killed the old crippled farm hand, Candy’s dog. This caused Candy to be lonely. Crook’s fits in to the loneliness theme because he is black. Being the only black man meant that he was isolated from everyone else at the ranch. Speaking of isolation, Curley’s wife feels very isolated because her husband, Curley, doesn’t trust her all. Loneliness causes depression in “Of Mice and Men” and in the world today.Loneliness is first illustrated in the story in Candy’s life because he is getting old he is afraid that he will be old and useless and no one will care about him. He is afraid that the boss will tell he has to leave the ranch and he will have nowhere to go. He is also lonely because his dog is old and sick. After few days later Candy’s dog has been killed by Carlson and buried on the field. “Had him since he was a pup” (pg. 56). He is also unable to work alongside the other men and is reduced to the role of swamper. On top of this, Candy doesn’t go into town with other men anymore. Candy is sad because he wants to believe that there is still some kindness in the world.Loneliness shows up next in the life of Crooks. Crooks is the only black man on the ranch and has been beaten down by the loneliness. When Lennie and Crooks first met, all of the other men went into town and Crooks did exactly what George did to Lennie when he first met him, take advantage of mental state. Crooks is jealous of their friendship. Crooks tried to persuade Lennie into thinking that George was not going to come back from town that day. In doing this Lennie became angry thinking that something had happened to George. After breaking the owner’s son’s hand a few days before, Crooks tried to persuade Lennie into thinking that if George didn’t come back from town that day. This puts him in a position of authority. It places him in a position where he can have control over a white man’ so to speak. In addition, because he has probably never had such sort of power that it would be overwhelming after all those years being that, ” A man goes nuts if he ain’t got no one to talk to”.(pg. 222)Curley’s wife, the farm owner’s son wife, shows loneliness. She is flirty city girl who is always getting herself into trouble with Curley because she flirts with the other men on the ranch. Curley is a lightweight boxer who does not like big guys just because he is not that big but that does not stop him at all. Most of the guys at the ranch stay clear of Curley and his wife because they know that if they get into any trouble with them they could be fired and because “Curley’s old man is the boss”.(pg. 72 ) Curley’s wife has really brought her loneliness upon herself is result of her constant flirting with everyone and because she does this, Curley cannot trust her to be around the other guys. Curley’s wife is also the only on the ranch, which means that she would be lonely from not having anyone to talk to apart from Curley. Although she is married to Curley, she doesn’t really love him. In the end, Curley’s wife has her neck broken by Lennie by accident. It is a tragedy for Curley’s wife but she did bring it upon herself.For this reason, loneliness is the major theme underlying theme, however, there are two herself are two little “branches” that come off that have to do with the three minor characters, and feeling of fear and jealousy. All of the characters are lonely, except George and Lennie who have each other. Candy is afraid of getting fired from job, Crooks is jealous of George and Lennie’s close relationship and the real loneliness comes from Curley’s wife. Loneliness leads to depression and it is a major theme in the novel, “Of Mice and Men”.