The Science of Grammar has three branches, which differ more in the methods they pursue than in the ends at which they aim. These are Historic, Comparative and Philosophic Grammar. Historic Grammar occupies itself with tracing the forms of a language back in time to their earlier expression, and exhibits their development through the archaic specimens of the tongue. Comparative Grammar extends this investigation by including in the survey the similar development of a number of dialects of the same stock or character, and explains the laws of speech, which account for the similarities and diversities observed. Both of these, it will be observed, begin with the language and its forms, and are confined to these. Philosophic Grammar, on the other hand, proceeds from the universal constructive principles of language, from the abstract formulæ of grammatical relations, and investigates their application in various languages. It looks upon articulate speech as the more or less faithful expression of certain logical procedures, and analyzes tongues in order to exhibit the success, be it greater or less, which attends this effort. The grammatical principles with which it deals are universals, they exist in all minds, although it often happens that they are not portrayed with corresponding clearness in language.[9-*] Philosophic Grammar, therefore, includes in its horizon all languages spoken by men; it essays to analyze their inmost nature with reference to the laws of thought; it weighs the relations they bear to the character and destiny of those who speak them; and it ascends to the psychological needs and impulses which first gave them existence. It was grammar in this highest sense, it was the study of languages for such lofty purposes as these, with which Humboldt occupied himself with untiring zeal for the last fifteen years of his life, when he had laid aside the cares of the elevated and responsible political positions which he had long filled with distinguished credit. § 5. DEFINITION AND PSYCHOLOGICAL ORIGIN OF LANGUAGE. Humboldt remarks that the first hundred pages or so of his celebrated “Introduction” are little more than an expansion of his definition of language. He gives this definition in its most condensed form as follows: “Language is the ever-recurring effort of the mind to make the articulate sound capable of expressing thought.”[10-*] According to this definition, language is not a dead thing, a completed product, but it is an ever-living, active function, an energy of the soul, which will perish only when intelligence itself, in its highest sense, is extinguished. As he expresses it, language is not an εργον, but an ενεργεια. It is the proof and the product of a mind _consciously_ working to a definite end.