1. Adjectives of QUALITY. 2. Adjectives of RELATION. 3. Adjectives of QUANTITY. 4. Adjectives of MODE. 1. Adjectives of Quality are those which designate the qualities of things as _good_ or _bad_, etc. They are susceptible of three Degrees of Comparison; and are, without due consideration, usually regarded by Grammarians as if they constituted the whole of the Adjective World. 2. Adjectives of Relation are, as we have seen, (chiefly) the Oblique Cases of the Noun Substantive. They admit of no Degrees of Comparison. These have not heretofore been regarded as Adjectives; but broadly and philosophically considered, they are so. 3. Adjectives of Quantity are the Numerals, which always instinctively find their way among the Adjectives in the Grammar Books, without their presence there being duly accounted for, that part of speech having been usually defined as relating exclusively to the _Quality_ of Things. These numeral Adjectives subdivide into Ordinal Numerals and Cardinal Numerals; and, like Adjectives of Relation, they are not susceptible of being varied by the Degrees of Comparison. 4. Adjectives of Mode relate to the Conditions of Existence, as _necessary_ and _unnecessary_, _important_ and _unimportant_, etc. They are somewhat ambiguous as to their susceptibility to comparison. It is over this class of Adjectives that the Grammarians dispute. If a thing is _necessary_, then, it is said, it cannot be _more necessary_, or _most necessary_, the Positive Case being itself Absolute or Superlative. In some cases this rule is not so clear, and there is doubt whether it is proper to apply the signs of Comparison or not. We may correctly say _more important_ and _most important_; and on the whole the Adjectives of Mode, or Modal Adjectives, are to be classed as capable of Comparison. These four classes of Adjectives again classify in respect to their usual susceptibility to comparison, as follows: Adjectives of Quality, } Adjectives of Mode } Capable of Comparison. Adjectives of Quantity, } Incapable of Comparison. Adjectives of Relation, } The _Principle_ of Comparison is itself _hierarchical_, or pertaining to gradation or rank divinely ordained; or as the mere scientist might prefer to say, naturally existent. It repeats, therefore, in an echo, or correspondentially, THE PERSON (First, Second, Third) of Nouns Substantive and Pronouns; and has relation to the Three Heads of the Ordinal Series of Number, 1st, 2d, 3d; as THE NUMBER of Nouns Substantive (Singular, Dual, and Plural) has relation to the Three Heads of the Cardinal Series of Number, 1, 2, 3.