Sir William Osler was known throughout his life as a great humanitarian. His writings touched all of us, and to persons of every race, creed, and color, he showed universal feelings of justice and mercy. Osler's writing supports great tolerance for all, yet Osler's contemporaries were far less broad-minded and not free of bigotry. Osler's role model, Sir Thomas Browne, wrote openly about his marked prejudices against Catholics, Jews, Moslems, and even women. This paradox between Osler's tolerance and humanitarianism and the prejudice and bigotry of his time, as well as his role model Browne, are explored.