Every book has its own theme, this being an implicit or recurrent idea or a motif. In John Steinbecks, Of Mice and Men, people could argue over the main theme. Some would declare "loneliness" as the main theme, while the next man would conclude "innocence." Others will shout "freedom", or "dreams", but I believe it is "relationships." Throughout the whole novel, the theme of relationships represents itself in the good, the bad, and the ugly.
One of the good relationships in this novel is that of Candy and his dog that he " "had [for] so long" " (44). Just knowing this, you can assume that it's a very close relationship between human and the dog companion. Even though a person without a dog would proclaim, " "nothing stinks as bad as an old dog"" (44), Candy would say, " "never notice how he stinks"" (44), this showing the deeper, poignant connection than the norm between them. This offers a very genuine relationship between the old and the innocent. While the other bunkers try to talk Candy into shooting his dog, he feels "uncomfortable" (44) and tries to postpone until "tomorra" (47). "Softly and hopelessly" (47), Candy agrees to have Carlson shoot his dog, and the only regret in the whole relationship is that " "[he] ought to of shot that dog [himself] [he] shouldn't ought to of let no stranger shoot [his] dog"" (61). Other than this contemplation, Candy and his dog have that of an unadulterated, pure relationship.
Comparing to the loving relationship between Candy and the dog, Lennie and George's relationship would fit into that of a much different category, this being the "bad" category. George often "scowled" (4, 21) at Lennie for all of his wrong doings, this forcing Lennie to nod "to show that he understood" (21). George isn't always mean to Lennie however, but instead, he "takes care of him" (22) either as an older brother or a father figure. He tells Lennie when " "[he's] scared"" (29), to warn him, or " "never speak to [Curley]"" (29), also letting him know that he's " "never been mad""(106) at him.