We are pleased to release this edition of Ralph Johnson’s The Rise of Informal Logic as Volume 2 in the series Windsor Studies in Argumentation. This edition is a reprint of the previous Vale Press edition with some typographical errors and other minor mistakes corrected. The prime motive for gathering Ralph H. Johnson’s essays under one cover is their clear articulation of the goals, concerns and problems of the discipline of informal logic. To my knowledge all of the published articles, (...) even of the 1980s, are still in print. But some are obtainable only by special request of a journal back issue. Their availability, even their existence, is not nearly widely enough known, and this volume is dedicated to remedying that disservice to those currently working in the field of informal logic, critical thinking, argumentation, and practical reasoning. Three of these sixteen pieces appear here in print for the first time. The previously published pieces have appeared from 1980 to 1992 as chapters in collective works or as articles in journals, and these in turn published in Canada, USA, The Netherlands and Belgium. It is hoped that gathering this hitherto scattered material under one cover will contribute to a greater understanding of what informal logic is, and to an enhanced sense of the impact of Johnson’s ideas. A discipline of informal logic might exist today without the writings of Johnson and his frequent co-author, J. Anthony Blair. But it would almost certainly be quite different from what it actually is. (shrink)

Addressing the slippery slope argument (SSA) in legal contexts from the perspective of pragma-dialectics, this paper elaborates the conditions under which an SSA-scheme instance is used reasonably (rather than fallaciously). We review SSA-instances in past legal decisions and analyze the basic legal SSA-scheme. By illustrating the institutional preconditions influencing the reasoning by which an SSA moves forward, we identify three sub-schemes (causal SSA, analogical SSA, and Sorites SSA). For each sub-scheme we propose critical questions, as well as four rules that (...) clarify when the SSA scheme is used reasonably. The institutional preconditions make the analogical SSA expectable in common law contexts; the Sorites SSA is expectable in civil law contexts; whereas the causal SSA is common to both contexts. This result should inform future work on the identification of typical argumentative patterns for the SSA in legal contexts. (shrink)