This passion, so unordered and yet so potent, explains the capacity for teaching that one frequently observes in scientific men of high attainments in their specialties-for example, Huxley, Ostwald, Karl Ludwig, Virchow, Billroth, Jowett, William G. Sumner, Halsted and Osler-men who knew nothing whatever about the so-called science of pedagogy, and would have derided its alleged principles if they had heard them stated.