What does Hally speculate about the social reformers of their age?

During Hally's conversation with Sam about social reformers, Sam shows himself to be educated and thoughtful, with somewhat of a romantic nature. His initial choices for "men of magnitude" are Shakespeare, Jesus, and Abraham Lincoln, which Hally rejects. Sam eventually wins Hally's approval by suggesting Alexander Fleming, the inventor of penicillin. Meanwhile, Hally chooses Darwin and Tolstoy, which represent his intellect and his respect for practical and science-based thought. However, the conversation itself says more about Hally's nature than his choices. He laughs when Sam chooses Abraham Lincoln, because Hally claims that Sam does not know what it was like to be a slave. Hally therefore reveals himself to be naive and shortsighted, unable to recognize that he lives in an environment that is in desperate need of a real social reformer (Mandela, perhaps?) and the true meaning of somebody who "benefit[s] all mankind" (19).