It also teaches that definitions are like tools in that some are better suited for a particular task than others.
Several chapters are devoted to informal fallacies.
A new classification is given for them, and the concept of proof is presented, without which some of the traditional informal fallacies cannot be explained adequately. Another chapter is devoted to division and classification, which occurs in all of the sciences. Other topics covered include the square of opposition, immediate inferences, and the syllogistic and chain arguments. It is surely the most complete and competent treatment of Aristotelian logic for the general student. The book is extremely clear and interesting.