<p>Argumentation Library </p><p>Leonard Nelson </p><p>A Theory of Philosophical Fallacies </p><p>Translated by Fernando Leal and David Carus </p><p>A Theory of Philosophical Fallacies </p><p>Argumentation Library </p><p>VOLUME 26 </p><p>Series Editor <br>Frans H. van Eemeren, University of Amsterdam, The Netherlands <br>Editorial Board <br>Bart Garssen, University of Amsterdam, The Netherlands <br>Scott Jacobs, University of Illinois at Urbana-Campaign, USA Erik C.W. Krabbe, University of Groningen, The Netherlands <br>John Woods, University of British Columbia, Canada </p><p>More information about this series at <a href="/goto?url=http://www.springer.com/series/5642" target="_blank">http://www.springer.com/series/5642 </a></p><p>Leonard Nelson </p><p>A Theory of Philosophical Fallacies </p><p>123 </p><p>Leonard Nelson Göttingen Germany </p><p>Translated by Fernando Leal and David Carus </p><p>Deceased—Leonard Nelson (1882–1927) </p><ul style="display: flex;"><li style="flex:1">ISSN 1566-7650 </li><li style="flex:1">ISSN 2215-1907&nbsp;(electronic) </li></ul><p>ISBN 978-3-319-20783-4&nbsp;(eBook) <br>Argumentation Library ISBN 978-3-319-20782-7 DOI 10.1007/978-3-319-20783-4 </p><p>Library of Congress Control Number: 2015945152 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2016 </p><p>Main text translated from the German language edition: Typische Denkfehler in der Philosophie by Leonard Nelson, © Felix Meiner Verlag 2011. All rights reserved </p><p>Appendix translated from the German language edition: “Die kritische Ethik bei Kant, Schiller und Fries: eine Revision ihrer Prinzipien”, Gesammelte Schriften in neun Bänden, vol. VIII, pp. 27–192 by Leonard Nelson, © Felix Meiner Verlag 1971. All rights reserved </p><p>This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. </p><p>Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com) </p><p>Contents </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1" target="_blank">Introduction by Fernando Leal</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1#Sec1" target="_blank">What Is the Theory? </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1#Sec2" target="_blank">Who Was Leonard Nelson? </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1#Sec3" target="_blank">Some Objections to the Theory</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1#Sec4" target="_blank">Note on the Translation </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_1#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>1269<br>13 18 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_2" target="_blank">Lecture I</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_2#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>21 28 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_3" target="_blank">Lecture II </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_3#Bib1" target="_blank">Reference</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>29 34 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_4" target="_blank">Lecture III </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_4#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>35 41 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_5" target="_blank">Lecture IV</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_5" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_5#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>43 50 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_6" target="_blank">Lecture V </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_6#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>51 56 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_7" target="_blank">Lecture VI</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_7" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_7#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>57 63 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_8" target="_blank">Lecture VI</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_8" target="_blank">I</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_8#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>65 71 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_9" target="_blank">Lecture VIII </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_9#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>73 81 </p><p>v</p><ul style="display: flex;"><li style="flex:1">vi </li><li style="flex:1">Contents </li></ul><p></p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_10" target="_blank">Lecture IX</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_10" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_10#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>83 89 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_11" target="_blank">Lecture X </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_11#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <br>91 98 </p><p></p><ul style="display: flex;"><li style="flex:1"><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_12" target="_blank">Lecture XI</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_12" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . </li><li style="flex:1">99 </li></ul><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_12#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;107 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_13" target="_blank">Lecture XI</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_13" target="_blank">I</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;109 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_13#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;116 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_14" target="_blank">Lecture XIII </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;117 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_14#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;125 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_15" target="_blank">Lecture XIV </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;127 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_15#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;134 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_16" target="_blank">Lecture XV </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;135 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_16#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;142 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_17" target="_blank">Lecture XVI </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;143 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_17#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;149 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_18" target="_blank">Lecture XVII</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_18" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;151 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_18#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;158 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_19" target="_blank">Lecture XVIII </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;159 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_19#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;165 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_20" target="_blank">Lecture XIX </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;167 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_20#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;174 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_21" target="_blank">Lecture XX </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;175 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_21#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;181 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_22" target="_blank">Lecture XXI </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;183 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_22#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;190 </p><p><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_23" target="_blank">Lecture XXII</a><a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_23" target="_blank">&nbsp;</a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;191 <a href="/goto?url=http://dx.doi.org/10.1007/978-3-319-20783-4_23#Bib1" target="_blank">References </a>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;200 </p><p>Appendix: Seven Kantian Fallacies. . . . . . . . . . . . . . . . . . . . . . . . . . .&nbsp;203 </p><p>Introduction by Fernando Leal </p><p>Abstract In 1921 Nelson presented what seems to be the first theory of philosophical argumentation, or at least of its negative or destructive part—a theory of philosophical fallacies. That theory says that the peculiar nature of philosophical thinking repeatedly leads people to take ordinary concepts with great philosophical import, such as causality or duty, and replace them with new, made-up ones, whose content is very different from that of the originally available ones. When the new concepts usurp the place of the original ones within a philosophical argument, they invariably produce false results—on all sides of philosophical disputes. Many apparently irresolvable disputes in philosophy are the product of such fallacious concept-swapping. </p><p>The relationship between philosophy and argumentation is, to say the least, peculiar. Philosophers argue all the time, that much we all know, even though quite often it is difficult, and sometimes exceedingly difficult, to make out what exactly their arguments are. But even conceding (for the sake of argument) that philosophy is all about arguing, it is again a hard fact that philosophers, in sharp contrast to mathematicians or scientists, are rarely if ever convinced by each other’s arguments. Moreover, the favourite occupation of philosophers is to pick holes in the arguments of their fellow philosophers, thereby indicating to the outside world that there is something rotten with all philosophical arguments. <br>None of this is controversial. A curious observer would therefore be readily excused if he or she would draw the conclusion that, surely, philosophers must have by now developed a theory of philosophical argumentation. This is hardly the case. A careful inspection of the relevant literature reveals it to consist basically of two kinds of publications. On the one hand, there are practical ‘textbooks’ purporting to give students some analytic tools to analyze and evaluate philosophical arguments or to construct and present their own. On the other hand, there are metaphilosophical texts presenting a certain view of the nature of philosophy with more or less loose </p><p>© Springer International Publishing Switzerland 2016 </p><p>L. Nelson, A Theory of Philosophical Fallacies, </p><p>1<br>Argumentation Library 26, DOI 10.1007/978-3-319-20783-4_1 </p><ul style="display: flex;"><li style="flex:1">2</li><li style="flex:1">Introduction by Fernando Leal </li></ul><p></p><p>observations about the role that arguments play or do not play in philosophy.<sup style="top: -0.3685em;">1 </sup>None of these books, however, present a systematic theory of philosophical argumentation as such, a theory of how philosophers actually argue or fail to argue.<sup style="top: -0.3685em;">2 </sup><br>This is the main reason why the book the reader is now holding in his or her hands merits attention. This book does present a theory of philosophical argumentation. It is perhaps too soon to say whether the theory is correct, entirely or in part, but it is quite a clear theory, so that at the very least it might start a much needed discussion about what a theory of philosophical argumentation should be. <br>In the following I shall first briefly state what that theory is, then I shall present its author, for he is not well known, and finally I shall endeavour to meet some objections that can be raised against the theory. </p><p>What Is the Theory? </p><p>Nelson’s theory of philosophical argumentation, as set forth in this book, is only a partial theory, for it only concerns those philosophical arguments that go wrong, that contain a fallacy, i.e. an error in reasoning. It does not say anything about philosophical arguments that are correct and fallacy-free. Moreover, the theory does not purport to cover all fallacies, but only the ‘typical’ ones, viz those that a philosopher will commit sooner or later because of the peculiar business he is in. Fallacies of such a typical sort are as it were an occupational hazard. <br>Even the plural—fallacies—has to be taken with a pinch of salt, for at bottom there is, according to the theory, only one typical fallacy in philosophical argumentation, although it comes in many shapes and forms. This may not look very promising. A theory of philosophical argumentation that is in fact about one fallacy? For it to work we must assume that in philosophy we will, always or at least for the </p><p><sup style="top: -0.3118em;">1</sup>To the first group belong e.g. Cornman et al. (1992), Rosenberg (1996), Morton (2004), Cohen (2004), Martinich (2005), Baggini and Fosl (2010); to the second e.g. Stove (1991), Glymour (1992), Bouveresse (1996), Williamson (2007), Gutting (2009), Schnädelbach (2012). I am naturally excluding from consideration those textbooks written by philosophers about argumentation in general (usually in view of courses in logic or critical thinking) as well as papers or books in which particular arguments of particular philosophers are subjected to scrutiny either for historical or systematic purposes. They may contain valuable remarks about philosophical argumentation but belong to a different ballgame altogether. A special case is Nicholas Rescher, who in a series of papers and books (e.g. 2001, 2006, 2008) has made some interesting, albeit in my opinion somewhat rambling, attempts at a theory of philosophical argumentation. <sup style="top: -0.3118em;">2</sup>There seem to be two theories of philosophical argumentation apart from Nelson’s. Johnstone (1959, 1978), developed in a long and distinguished career a theory that is both profound and undeservedly underrated by philosophers, although it has fortunately met with some attention in the field of argumentation studies (see e.g. the special issue in his honour in Informal Logic, 2001, as well as van Eemeren and Houtlosser 2007). I can see clear points of contact as well as undeniable differences between Johnstone’s theory and Nelson’s, and I certainly hope to tackle the task of comparing them in the future. As for the other theory, see Footnote 7 of this chapter. </p><ul style="display: flex;"><li style="flex:1">What Is the Theory? </li><li style="flex:1">3</li></ul><p></p><p>most part, reason correctly if only we avoid that one fallacy to whose description and illustration this whole book is devoted. That is exactly what Nelson assumes. <br>But what exactly is this fallacy? The analysis that uncovers it is a two-step procedure. </p><p>Step 1&nbsp;Nelson starts with the fact that a philosophical argument is always part of an ongoing, if not always fully explicit, discussion between philosophers each one of whom affirms something that appears to imply denying what the other holds. The logical building constituted by the opposing arguments Nelson calls the ‘dialectics’ of the issue at hand—harking back to Plato, who invented the term to name the peculiar art of dialogue developed by his master, Socrates. Although such logical buildings—the sets of propositions and arguments pitted against each other all along the history of philosophy—can sometimes be abstruse and convoluted, Nelson’s analysis tries to reduce the basic opposition to its raw core, which he sometimes represents in the shape of elegant diagrams. The reader will find in this book five of those. Popper for one expressed his admiration for this analytical feat of reduction and tried to imitate it (see Popper 1979). <br>Those diagrams show that the way philosophers arrive at their positive philosophical doctrines is byway of denying the positive doctrines of their opponents. They manage to believe they have proved something, say P, because they have shown the opposite doctrine, say Q, to be false. Their opponents play exactly the same game, so that the net result is the appearance of a relation of contradiction between P and Q where there is in fact no such contradiction. The game is played again and again by philosophers on the strength of a common assumption, a usually hidden presupposition shared by the two adversaries, viz that P and Q exhaust all possibilities available to philosophical thought. Yet if P and Q exclude each other, their negations do not. In other words, if P is true, then Q has to be false, and if Q is true, then P has to be false; but if P is false, Q does not have to be true, and if Q is false, P does not have to be true. In the traditional logical jargon, the two philosophical doctrines are not contradictory but rather contrary to each other—they cannot both be true yet they may very well both be false, viz if the common assumption that they are the only alternatives is itself false. The starting point of the discussion is then the choice between two options (either P or Q), a logical disjunction which is understood by both discussion partners as being both exclusive and exhaustive. Starting from such a disjunction the discussion evolves in a predictable way, which Nelson’s diagrams try to represent in a terse, parsimonious manner. If we use arrows to indicate an inferential relation, then the following would be the general form of a Nelson diagram: </p><p></p><ul style="display: flex;"><li style="flex:1">4</li><li style="flex:1">Introduction by Fernando Leal </li></ul><p></p><p>We see here that there is contradiction between P and not-P as well as between <br>Q and not-Q, but there is no contradiction between P and Q; not even if we concede that P and Q exclude one another. At least there is no contradiction unless and until we assume that tertium non datur, that there is no third possibility, say R, which excludes both P and Q. Nelson’s argument is not only that R is available but that R is indeed the true alternative. <br>So far we would have one form of what is usually referred to as a false dilemma or a false dichotomy (Nelson himself calls it an ‘incomplete disjunction’). It would not be much of an exaggeration to say that for Nelson the history of philosophy has a dilemmatic structure, and that all breakthroughs in that history consist in showing some of these dilemmas to be false. But the question now arises as to why philosophers become prisoners of a false dilemma in the first place. This leads to the second, and the most important, step in Nelson’s analytical procedure. </p><p>Step 2 This consists in breaking down the sentences and arguments used in philosophical disputes so as to identify the underlying concepts. The leading idea is that quite often at least one of those is a fake and a phony, an extra-ordinary concept masquerading for an ordinary one by an artful or unwitting sleight of hand, something that a philosopher has made up instead of respecting the meanings our common vocabulary puts at our disposal. Such a replacement of one concept by a different one—sometimes introduced by a seemingly harmless definition—creates an instance of equivocation, or what in traditional syllogistic was called quaternio terminorum, a well-known fallacy by which the same word or phrase is used, within the same argument, in more than one meaning. When this happens, a false dilemma </p>