But the principles of all practical grammar, whether universal or particular, common or peculiar, must first be learned in their application to some one language, before they can be distinguished into such classes; and it is manifest, both from reason and from experience, that the youth of any nation not destitute of a good book for the purpose, may best acquire a knowledge of those principles, from the grammatical study of their native tongue.
15.

Universal or Philosophical Grammar is a large field for speculation and inquiry, and embraces many things which, though true enough in themselves, are unfit to be incorporated with any system of practical grammar, however comprehensive its plan.

Many authors have erred here.

With what is merely theoretical, such a system should have little to do.

Philosophy, dealing in generalities, resolves speech not only as a whole into its constituent parts and separable elements, as anatomy shows the use and adaptation of the parts and joints of the human body; but also as a composite into its matter and form, as one may contemplate that same body in its entireness, yet as consisting of materials, some solid and some fluid, and these curiously modelled to a particular figure.