This is true; but it is also true that the traditional grammar has still a great hold on the mind of the student.
Metaphysics are even more troublesome than the figments of grammar, because they wear the appearance of philosophy and there is no test to which they can be subjected. They are useful in so far as they give us an insight into the history of the human mind and the modes of thought which have existed in former ages; or in so far as they furnish wider conceptions of the different branches of knowledge and of their relation to one another.
But they are worse than useless when they outrun experience and abstract the mind from the observation of facts, only to envelope it in a mist of words. Some philologers, like Schleicher, have been greatly influenced by the philosophy of Hegel; nearly all of them to a certain extent have fallen under the dominion of physical science. Even Kant himself thought that the first principles of philosophy could be elicited from the analysis of the proposition, in this respect falling short of Plato. Westphal holds that there are three stages of language: (1) in which things were characterized independently, (2) in which they were regarded in relation to human thought, and (3) in relation to one another. But are not such distinctions an anachronism? for they imply a growth of abstract ideas which never existed in early times. Language cannot be explained by Metaphysics; for it is prior to them and much more nearly allied to sense. It is not likely that the meaning of the cases is ultimately resolvable into relations of space and time. Nor can we suppose the conception of cause and effect or of the finite and infinite or of the same and other to be latent in language at a time when in their abstract form they had never entered into the mind of man...If the science of Comparative Philology had possessed 'enough of Metaphysics to get rid of Metaphysics,' it would have made far greater progress.
(4) Our knowledge of language is almost confined to languages which are fully developed. They are of several patterns; and these become altered by admixture in various degrees,--they may only borrow a few words from one another and retain their life comparatively unaltered, or they may meet in a struggle for existence until one of the two is overpowered and retires from the field. They attain the full rights and dignity of language when they acquire the use of writing and have a literature of their own; they pass into dialects and grow out of them, in proportion as men are isolated or united by locality or occupation. The common language sometimes reacts upon the dialects and imparts to them also a literary character. The laws of language can be best discerned in the great crises of language, especially in the transitions from ancient to modern forms of them, whether in Europe or Asia. Such changes are the silent notes of the world's history; they mark periods of unknown length in which war and conquest were running riot over whole continents, times of suffering too great to be endured by the human race, in which the masters became subjects and the subject races masters, in which driven by necessity or impelled by some instinct, tribes or nations left their original homes and but slowly found a resting-place. Language would be the greatest of all historical monuments, if it could only tell us the history of itself.