Book excerpt: This book works through some of the theoretical issues that have been accumulating in informal logic over the past 20 years. At the same time, it defines a core position in the theory of argument in which those issues can be further explored. The underlying concern that motivates this work is the health of practice of argumentation as an important cultural artifact. A further concern is for logic as a discipline. Argumentative and dialectical in nature, this book presupposes some awareness of the theory of argument in recent history, and some familiarity with the positions that have been advanced. It will be of interest to academics, researchers, and advanced undergraduate and graduate students in the disciplines of logic, rhetoric, linguistics, speech communication, English composition, and psychology.