Nor are they always principles or parts of _words_: we sometimes write what is _not a word_; as when, by letters, we denote pronunciation alone, or imitate brute voices.

If words were formed of articulate sounds only, they could not exist in books, or be in any wise known to the deaf and dumb.

These two primary definitions, then, are both false; and, taken together, they involve the absurdity of dividing things acknowledged to be indivisible.

In utterance, we cannot divide consonants from their vowels; on paper, we can.

Hence letters are the least parts of written language only; but the least parts of spoken words are syllables, and not letters.
Every definition of a consonant implies this.
15.