To demonstrate that this is so, we do not need to enter into a detailed examination of two tongues claimed to be unrelated, and show that their correspondences fall incontestably short of the amount required to prove relationship: we may take a briefer and directer argument. We have seen that the established linguistic families are made up of those dialects which exhibit traceable signs of a common historic development; which have evidently grown together out of the radical stage (unless, as in the case of the monosyllabic tongues, they have together remained stationary in that stage); which possess, at least in part, the same grammatical structure. There are some linguistic scholars who cherish the sanguine hope that trustworthy indications of this kind of correspondence may yet be pointed out between some two or three of the great families; but no one whose opinion is of one straw's weight thinks of such a thing with reference to them all. So discordant is the whole growth of many of the types of speech that we can find no affinities among them short of their ultimate beginnings: if all human speech is to be proved of one origin, it can only be by means of an identification of roots. To give the investigation this form, however, is virtually to abandon it as hopeless. The difficulties in the way of a fruitful comparison of roots are altogether overwhelming. To trace out the roots of any given family, in their ultimate form and primitive signification, is a task whose gravity the profoundest investigators of language are best able to appreciate. Notwithstanding the variety of the present living dialects of the Indo-European family, and the noteworthy preservation of original forms on the part of some among them, their comparison would be far enough from furnishing us the radical elements of Indo-European speech. Even the aid of the ancient tongues but partially removes the difficulty; and, but for the remarkable and exceptional character of the Sanskrit, our knowledge of that stage in the history of our language out of which its present grammatical structure was a development would be but scanty and doubtful; while we have been compelled to confess (in the seventh lecture) that we know not how far even so primitive a stage may lie from the absolute beginning.
