Hence, language is the most perfect example of ethnic psychical action. It is the product of the group, to which each individual of the group contributes his share, and which is the common property of all, reflecting at once the traits of the group and the relations of the individual to it. Nor is language a merely temporary criterion of group-character. Conspicuously not. Nothing clings so tenaciously to us as our mother tongue. Religions may fade and institutions decay, we may change our clime and culture, but the tongue persists. It is passed from generation to generation, exceeding count. No heirloom is so cherished, no tradition so hoary. By the Aryan tongues of modern Europe antiquaries have restored the mode of life of that primitive horde who spoke the ancestral speech of all the Indo-European peoples, now stretching in an unbroken line from Farther India to San Francisco. Unnoticed but indelible, the ethnic life of that horde left its impressions on its speech like the footsteps on geologic strata from which the palæontologists reconstruct the strange forms of extinct species. As the individual can convey his thoughts, his personality to the group, in the language of the group, he is confined and limited by that language. Hence the sovereign necessity in this investigation to study not merely the contents of a tongue, its verbal richness and resources, but that subtler side of it, its form or morphology. Indeed, the highest aim of linguistic science, of the _philosophy_ of language, is to estimate the influences of the various forms of speech not merely on the expression, but on the formation of ideas. We think in words and in grammatical relations, and both should be logical and accurate if our expressed results shall be so also. Few but specialists are aware how widely the varieties of human speech differ in the power they exert of this formative character. Suppose that in English we could not speak of that “divine tool,” the hand, except as a bodily member belonging to some particular person, “my hand” or “John’s hand”; how it would crush all means of generalisation, shut in our minds to present and local cases! Yet this is the case in hundreds of American and some Asiatic dialects, not only with this but many classes of concepts. How are we to convey the simplest arithmetical relations to tribes who have no words for integers beyond 5? What is more hopeless, how can a member of such a tribe ever become an arithmetician of his own effort? Thus an individual is a mental slave to the tongue he speaks. Virtually, it fixes the limits of his intellectual life. His most violent efforts cannot transcend them. Here the group, the ethnic mind exercises tyrannical sway over him.