The implement of literature is the language. First we have to know the language, and then we must be armed with the craft of using it. The thing looks easy, as all of us use the language every day, but it is really difficult, because literature is something that is expressed by ordinary language to produce an extraordinary effect.
A man of letters must apprehend the language more precisely and thoroughly than the ordinary people, so that he can use it at his will. He must understand the form, the sound, and the meaning of a word, as well as the effects of the arrangements of words in connexion with the sound and meaning to be left by the reader. This will involve such knowledge as philology, logic, grammar, aesthetics, and psychology.