Douglas N. Walton is Professor in the Department of Philosophy at the University of Winnipeg. He is the author of Plausible Argument in Everyday Conversation, also published by SUNY Press and The Place of Emotion in Argument. Erik C. W. Krabbe is Associate Professor of Logic and Argumentation Theory in the Philosophy Department at Groningen University. He is the coauthor of From Axiom to Dialogue: A Philosophical Study of Logics and Argumentation, and coeditor of Logic and Political Culture: Proceedings of the Colloquium 'Logic and Politics', Amsterdam 19-22 February 1990 and Empirical Logic and Public Debate: Essays in Honour of Else M. Barth.