Doc Burton
Doc Burton is the novel’s most metaphorical character, inspired by Steinbeck’s friend Edward Ricketts and infused with the philosophical worldview inhabited by Ricketts. Doc Burton is essentially a personification of the abstract metaphorical concept of non-teleological thinking. Burton is the living embodiment of this mode of thought which bypasses the vain path of trying to answer the question of why things happen and instead focusing on the more matter-of-fact nature of what has actually happened or—at its most abstract—how things happened.
Group-Man versus Man
The novel essentially tells of the conflict between two distinct and separate groups who coalesce common interests to themselves, but which both ultimately act in ways irresponsible relative to upholding the democratic ideals Steinbeck held so dear. One of the book’s most power engagements of metaphor describes how Steinbeck felt about such lack of individualism:
"A man in a group isn't himself at all; he's a cell in an organism that isn't like him any more than the cells in your body are like you.”
Running Hot and Cold
Steinbeck typically puts his similes into the mouths of his characters and it is an effective means of conveying character. For instance, you don’t much more information to put together what is likely a fairly accurate profile of the man who says this:
“O.K. We got plenty of fire now. That’s the trouble with workin’ stiffs, though. One minute they’re steamed up like a keg of beer, and the next, they’re cold as a whore’s heart. We got to cut down the steam and warm up the cold.”
Capitalists and Communists
The two groups which are pitted against each other definitely need to be read metaphorically. One might well supposed that the man who wrote The Grapes of Wrath would paint the greedy capitalist ownership class as purely villainous and the communist organizers working on behalf of the workers far more sympathetically. In reality, these two camps are both metaphorical exemplars of Group-Men thought that infects the body politic like a virus that ultimately destroys all sense of individuality. Steinbeck saw the value of community, but in his creation of two metaphorical entities dependent upon group-thought for survival, he seems to be suggesting that the primary difference is a sense of community does not seek to destroy the individual.
The Non-Teleological Approach to Group-Man
Steinbeck brings two metaphorical obsessions of the novel together in the figure of his most metaphorical figures: Doc and Mac. Mac is a metaphorical figure of the paradox of trying to find a personal identity through alignment with the group. Doc’s response to this is not to explain any aspect, but rather examine it for what Mac is within the dynamic or how he might work within the dynamic through revisiting the comparison of the group-man to a cell within an organism.
“You might be an effect as well as a cause, Mac. You might be an expression of group-man, a cell endowed with a special function, like an eye cell, drawing your force from group-man, and at the same time directing him, like an eye. Your eye both takes orders from and gives orders to your brain.”