From Mark Twain's "nineteen rules governing literary art in domain of romantic fiction" and how James Fenimore Cooper violated all of them:

3. They require that the personages in a tale shall be alive, except in the case of corpses, and that always the reader shall be able to tell the corpses from the others. But this detail has often been overlooked in the "Deerslayer" tale.

...

7. They require that when a personage talks like an illustrated, gilt-edged, tree-calf, hand-tooled, seven-dollar Friendship's Offering in the beginning of a paragraph, he shall not talk like a negro minstrel in the end of it. But this rule is flung down and danced upon in the "Deerslayer" tale.

He goes on:

I may be mistaken, but it does seem to me that "Deerslayer" is not a work of art in any sense; it does seem to me that it is destitute of every detail that goes to the making of a work of art; in truth, it seems to me that "Deerslayer" is just simply a literary delirium tremens.

A work of art? It has no invention; it has no order, system, sequence, or result; it has no lifelikeness, no thrill, no stir, no seeming of reality; its characters are confusedly drawn, and by their acts and words they prove that they are not the sort of people the author claims that they are; its humor is pathetic; its pathos is funny; its conversations are — oh! indescribable; its love-scenes odious; its English a crime against the language.

Counting these out, what is left is Art. I think we must all admit that.