This book is a type of "tooth and claw" criticism of James Fenimore Cooper's writings, focusing primarily on Deerslayer and Pathfinder from the Leatherstocking Tales. Twain begins by quoting a few critics who praise the works of Cooper, and then shortly claims that they have never read the articles themselves.
Twain states that Cooper scores 114 offenses out of 115 in two thirds of a page, thus breaking a record. He goes on to list 18 separate literary rules he feels that Cooper does not follow. Among these, he claims, "The tale shall accomplish something and arrive somewhere. But the "Deerslayer" accomplishes nothing and arrives in the air," and "The author shall use the right word, not its second cousin." Twain continues on with little positive things to say about Cooper's writing, even citing some examples from Cooper's writing to stress the incredibility of his style.