The degrees belong to any beings or ideas that may be known or conceived of as possessing quality; as, “untamed thought, great, giant-like, enormous;” “the commonest speech;” “It is a nobler valor;” “the largest soul.”

Also words of quantity may be compared:  for example, “more matter, with less wit;” “no fewer than a hundred.”

[Sidenote:  Words that cannot be compared.]

156.  There are some descriptive words whose meaning is such as not to admit of comparison; for example,—­

     His company became very agreeable to the brave old professor of
     arms, whose favorite pupil he was.—­THACKERAY.

     A main difference betwixt men is, whether they attend their own
     affair or not.—­EMERSON

     It was his business to administer the law in its final and
     closest application to the offender—­HAWTHORNE.

     Freedom is a perpetual, organic, universal institution, in
     harmony with the Constitution of the United States.—­SEWARD.

So with the words sole, sufficient, infinite, immemorial, indefatigable, indomitable, supreme, and many others.

It is true that words of comparison are sometimes prefixed to them, but, strictly considered, they are not compared.

[Sidenote:  Definition.]

157.  Comparison means the changes that words undergo to express degrees in quality, or amounts in quantity.

[Sidenote:  The two forms.]

158.  There are two forms for this inflection:  the comparative, expressing a greater degree of quality; and the superlative, expressing the greatest degree of quality.

These are called degrees of comparison.

These are properly the only degrees, though the simple, uninflected form is usually called the positive degree.

159.  The comparative is formed by adding _-er_, and the superlative by adding _-est_, to the simple form; as, red, redder, reddest; blue, bluer, bluest; easy, easier, easiest.

[Sidenote:  Substitute for inflection in comparison.]

160.  Side by side with these inflected forms are found comparative and superlative expressions making use of the adverbs more and most.  These are often useful as alternative with the inflected forms, but in most cases are used before adjectives that are never inflected.

They came into use about the thirteenth century, but were not common until a century later.

[Sidenote:  Which rule,—­ -er and -est or more and most?]

161.  The English is somewhat capricious in choosing between the inflected forms and those with more and most, so that no inflexible rule can be given as to the formation of the comparative and the superlative.