“Intellectually, what is stimulating to a young man is a problem of obvious practical importance. A young man learning economics, for example, ought to hear lectures from individualists and socialists, protectionists and free-traders, inflationists and believers in the gold standard. He ought to be encouraged to read the best books of the various schools, as recommended by those who believe in them. This would teach him to weigh arguments and evidence, to know that no pinion is certainly right, and to judge men by their quality rather than by their consonance with preconceptions.”