In recent years the study of practical reasoning and arguments and argumentation has become a topic not just in philosophy courses but also in departments of Communication and English as well as in professional schools of law and business. The resulting field and analysis and instruction goes by different names in different contexts: informal and logic and rhetoric among many others. An Introduction to Reasoning has been written with an eye to the needs of all the current types of course and will serve as a general introduction to them. Therefore the book presuppose no familiarity with formal logic. It is designed for use in courses intended to provide an introduction to ideas about rationality and criticism without requiring a mastery of any particular logical formalism.