The philosopher is unnamed in Walden, although scholars generally agree that Thoreau was referring to Amos Bronson Alcott, father of Louisa May Alcott, the author of Little Women. Alcott was a friend of Ralph Waldo Emerson and a Transcendentalist himself. He is perhaps best known for his innovative experiments in education and his experiments with communal living.
By not using his name, Thoreau draws attention to the features that made Alcott an exemplary philosopher. A "true friend of man; almost the only friend of human progress," the philosopher isn't some snooty guy stuck in an ivory tower, but a man who has tremendous faith in human nature. He has a "hospitable intellect" that "embraces children, beggars, insane, and scholars, and entertains the thought of all, adding to it commonly some breadth and elegance" (Former Inhabitants.21). This philosopher has a faith in human goodness and progress that outshines Thoreau's. While Thoreau sometimes rags on humanity, the philosopher never does.