How could it be argued that Slim's opinions could be the opinions of Steinbeck in Of Mice and Men?
Each of the characters in Of Mice and Men have some critical flaw in their character. Lennie is too much like a child, while George has to do the unthinkable. Candy does not stand up for his dog, Curley's wife is self- indulgent and very sad, while Curley is abusive and aggressive. However, Steinbeck does not create anything negative within Slim's character, reflecting how Slim's opinions could be Steinbeck's.
In Chapter 2, Steinbeck describes Slim in a complimentary manner. Phrases like "His ear heard more than was said to him, and his slow speech had overtones not of thought, but of understanding beyond thought" along with terms such as "prince of the ranch" and "master craftsman" help to vault Slim into a level different than any other character. Steinbeck says that Slim possesses an "understanding beyond thought," honed through his ability to listen to other people. Slim shows this when he listens to George talk about his past with Lennie and even in the way he acknowledges Crooks in a way that no one else does. Slim's presence is almost "god like" in the way he inspires trust in the people around him.
Slim's ability to connect with other people is similar to Steinbeck, himself. Steinbeck spent time with migrant workers in order to fully understand their predicament. This is translated in the rich way characters are developed, settings are created, and in how emotional dynamics are transmitted. Steinbeck once wrote, "I wonder how many people I have looked at all my life and never really seen." In writing Of Mice and Men, Steinbeck paid attention to socially marginalized people. Like Steinbeck, Slim notices everything as he validates the stories of other people. Slim's talent as a skinner and his attributes as a human being make him fundamentally different than all others on the ranch. Slim's approach to people and his opinion about them are similar to Steinbeck's. They both appreciate the narratives of the people around them, listening more than they talk, but speaking with a "majesty" that most lack.