Whether a nation or a society of nations will ever proceed as far as this, or, going farther, will attempt the fuller art of stirpiculture, encouraging useful “crosses” of families or races, may be matter of grave doubt; but if the maintenance and improvement of the national stock ever warranted such experiments, we are entitled to insist that logic would justify the application of the same rule in the society of nations.
Again, while it is questionable how far the law of the utility of cross-fertilisation is transferable from the world of physical organisms to the psychical realm in its literal bearing, the more general applicability cannot be disputed. That scientific theories, religious, social, and political arts and institutions gain by free, friendly, vital intercourse with other theories, arts, and institutions, undergoing serviceable accretions, excretions, and modifications, is a commonplace of intellectual life. Whether, therefore, we regard the contact of ideas and feelings and the arts they animate as a direct struggle for existence, in which the worse or falser perish and the better and truer survive, or as a friendly intercourse in which each selects and assimilates something from the others, internationalism is as essential to the