FEW things are more fascinating, and none more difficult, than to discover the hidden springs of national achievement. Among the achievements of the English-speaking peoples is the institutionalization of liberty. As an achievement which in modern times has saved them from such plagues as dictatorships and reigns of terror, it has been of particular interest to foreigners-especially, perhaps, to the French, whose own genius it has often been to explore the genius of other peoples. Montesquieu found liberty in England, Tocqueville democracy in America. Mrs. Letwin’s concern with the English gentleman is an enterprise of a not altogether dissimilar kind. It is, indeed, hardly concerned with institutional generalization at all, but it acquires sharpness of focus from exploring the character of the gentleman in terms of the imaginative world created by Anthony Trollope in the nineteenth century.