Informal logic

This introductory text teaches readers how to build strong arguments and how to spot weak ones. Written without heavy technical jargon, it works through 186 examples, each examined closely by Douglas Walton, a prominent figure in informal logic. Walton shows where mistakes, fallacies and other common breakdowns in reasoning come from, and he lays out sound methods for persuading others through reason and for answering objections.

The book covers a wide range of topics. Readers encounter valid argument forms, defeasible arguments that can be overturned by new evidence, and the question of relevance. Other chapters look at appeals to emotion, personal attacks, the straw man tactic, and the habit of jumping to conclusions. Walton also examines how expert opinion is properly used and misused, what goes wrong when drawing conclusions from polls and statistics, and how loaded terms, equivocation and analogies can mislead. The final topics address how to pose questions, respond to them, and critique them effectively.