In what ways does John Steinbeck explore the idea of love in his novel, ‘Of Mice and Men’?

In the first half of the book, Steinbeck shows the reader George and Lennie’s complex friendship largely through dialogue. When George mentions the possibility of living alone, George, though indifferent at first, begs Lennie not to go; “I want you to stay with me.” Steinbeck repeats this later, with, “no, you stay with me.” This phrase is slightly vulnerable and highlights how George, despite his aloofness, actually needs Lennie as much as Lennie needs him. The section of text leading on from “George’s voice became deeper” indicates the nature of the relationship between George and Lennie. George is the father figure in their relationship; “deeper” suggests that his voice changes to soothe Lennie as he has told this story to Lennie “many times before.” This shows that George tells this tale almost as a bedtime story which enforces the feeling in the reader that Lennie is like a child. 
A different form of love that is explored in the novel is the the love Candy feels for his old dog. When the two characters are introduced, “the swamper [Candy] watched him [the dog] until he was settled”, and when George enquires about the dog, Candy fondly remembers how he had ‘im since he was a pup.” This shows how aged their love is, yet how much Candy still cares so greatly for it despite it being a relatively useless pet to keep. This is further emphasised by how often he mentions how great the old dog was; “he was the best damn sheep dog I ever seen.” The dog is not worth keeping; it cannot eat, yet Candy “feeds him milk” showing how the dog is like a child to Candy and the only thing he cares about. The futility of Candy’s persuasions to keep the dog alive show the reader how desperately Candy wants to keep him, and the extent of his love. During the entire conversation, he “looks about unhappily” and scratches “his cheek nervously”, and his amount of distress shows when he “looked for help from face to face.” This actively demonstrates how he is silently pleading with the men to understand his pain and the loss he will feel if the dog dies, and how dear the animal is to him. He ends up clutching at straws - when the decision for the dog’s death has been made, he mentions “hopefully” that Carlson “ain’t got no gun” as well as pleading for the death to be moved to “maybe tomorra.” The “maybe” symbolises how Candy may never really be able to see his dog go, albeit recognising this is the right thing to do. He eventually gives in, and the loss of love from Candy’s life is personified by silence; “the silence came into the room.” This demonstrates how powerful silence is at that moment; as if it is sitting there with the characters, and how the dog leaving has caused everyone to be quiet. Additionally, it contrasts with an alternate scenario - earlier, it could have been possible for the dog to come in, but now only silence can, symbolising the loss of the dog. The repetition of “silence” indicates to the reader how Candy cannot quite get past the loss of his dog, showing the greatness of his love for him.