Thus, if I would define a _globe_, a _wheel_, or a _pyramid_, my description must be taken, not from what is peculiar to one or an other of these things, but from those properties only which are common to all globes, all wheels, or all pyramids.

But what property has _unity_ in common with _plurality_, on which a definition of _number_ may be founded?
What common property have the _three cases_, by which we can clearly define _case_?
What have the _three persons_ in common, which, in a definition of _person_, could be made evident to a child?
Thus all the great classes of grammatical modifications, namely, _persons, numbers, genders, cases, moods_, and _tenses_, though they admit of easy, accurate, and obvious definitions in the plural, can scarcely be defined at all in the singular.

I do not say, that the terms _person, number, gender, case, mood_, and _tense_, ia their technical application to grammar, are all of them equally and absolutely undefinable in the singular; but I say, that no definition, just in sense and suitable for a child, can ever be framed for any one of them.

Among the thousand varied attempts of grammarians to explain them so, there are a hundred gross solecisms for every tolerable definition.

For this, as I have shown, there is a very simple reason in the nature of the things.
35.