This brings us to the third sense in which unity can be predicated of a cultural group.  The unity that depends on the interconnexion of distinct parts implies some differences of character.  Western civilization has lost something of the unity of character which it owed to its common origin, though it still retains enough of it to figure as a single whole in contrast to the rest of the world.  We may be sure that the differences between German, French, and English seem much less marked to the intelligent Chinese than they are to Germans, Frenchmen, and English themselves.  We ourselves habitually think of China and Japan together as denizens of the Far East, and it is only personal acquaintance which makes us begin to mark the differences between them.  Few Europeans, I imagine, get as far in their discrimination as to appreciate the distinctions between the Northern and Southern Chinese, which are as clear to the Chinese themselves as the difference between English and Scottish is to us.  Western civilization does retain a generic unity of character, though national differences have had an increasing influence in the sphere of thought.  Meanwhile the unity of interconnexion has on the whole grown closer with the spread of education, the multiplication of learned magazines and the facilities of travel.  One of the most interesting chapters in the development of modern thought can be written, as Dr. Merz has shown by example as well as by precept, on the theme of the mutual influence of the great national centres of thought, and in particular of France, England, and Germany.  These nations might seem as though designed, whether by nature or by the unconscious hand of political history, to be half-willing, half-reluctant complements to each other.  English common sense, French lucidity, German idealism; English liberty, French equality, German organization; English breadth, French exactitude, German detail,—­how much poorer the world would be if any one of these had been allowed to develop on its own lines without the criticism of the other two.  What a special providence gave the easy-going Englishman a northern neighbour to lecture him on German metaphysics in his own tongue and compel him to the definiteness which he instinctively detests.  Without Scotland as a link, the connexion between English and German thought would hardly have been effective and continuous, and it was a Scotsman who aroused the greatest of German metaphysicians—­himself of Scottish descent—­from his dogmatic slumbers.

This international division of labour is more significant in the regions of metaphysics and political thought than of physical science.  To science, every modern nation has contributed both great names and useful journeyman work.  Through the medium of the learned reviews and of periodical congresses science has become more and more international.  It is still possible now and again for a great discovery like that of Mendel or an important hypothesis like that of the kinetic