Abduction, Reason, and Science Abduction, Reason, and Science Processes of Discovery and Explanation
Lorenzo Magnani University of Pavia Pavia, Italy, and Georgia Institute of Technology Atlanta, Georgia
Springer Science+Business Media, LLC Library of Congress Cataloging-in-Publication Data
Magnani, Lorenzo Abduction, reason, and ,cience: processes of discovcry and explanation/Lorenzo Magnani. p. cm. IncIudes bibliographical references and index. ISBN 978-1-4613-4637-1 ISBN 978-1-4419-8562-0 (eBook) DOI 10.1007/978-1-4419-8562-0 1. Science-Philosophy. 2. Abduction (Logic). 3. Discoveries in science. I. Tirle.
Q175.32.A24 M34 2001 501-dc21 00-052061
Front cover: Descartes's explanation of the rainbow (from his Meteora, 1656).
ISBN 978-1-4613-4637-1 © 2001 Springer Science+Business Media New York Originally published by Kluwer Academic / Plenum Publishers, New York in 2001 Softcover reprint of the hardcover 1st edition 1990 http://www.wkap.nl/ 1098765432 A c.I.P. record for this book is available from the Library of Congress. AII rights reserved No par! of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without wrilten permis sion from the Publisher To my daughter Giovanna Science does not rest upon solid bedrock. The bold structure of its theories rises, as it were, above a swamp. It is like a building erected on piles. The piles are driven down from above into the swamp, but not down to any natural or "given" base; and if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being. Karl R. Popper, The Logic of Scientific Discovery Foreword by Paul Thagard
More than a hundred years ago, the great American philosopher Charles Sanders Peirce coined the term "abduction" to refer to inference that involves the generation and evaluation of explanatory hypotheses. The study of abduc tive inference was slow to develop, as logicians concentrated on deductive logic and on inductive logic based on formal calculi such as probability the ory. In recent decades, however, there has been renewed interest in abductive inference from two primary sources. Philosophers of science have recognized the importance of abduction in the discovery and evaluation of scientific theo ries, and researchers in artificial intelligence have realized that abduction is a key part of medical diagnosis and other tasks that require finding explana tions. Psychologists have been slow to adopt the terms "abduction" and "ab ductive inference" but have been showing increasing interest in causal and explanatory reasoning. Thus abduction is now a key topic of research in cognitive science, the in terdisciplinary study of mind and intelligence. Lorenzo Magnani 's new book contributes to this research in several valuable ways. First, it nicely ties to gether the concerns of philosophers of science and AI researchers, showing, for example, the connections between scientific thinking and medical expert systems. Second, it lays out a useful general framework for discussion of various kinds of abduction. Third, it develops important ideas about aspects of abductive reasoning that have been relatively neglected in cognitive science, including the use of visual and temporal representations and the role of ab duction in the withdrawal of hypotheses . The author has provided a fine con tribution to the renaissance of research on explanatory reasoning.
Paul Thagard Philosophy Department University of Waterloo Waterloo , Ontario, Canada
IX Preface
This volume explores abduction (inference to explanatory hypotheses), an important but neglected topic in scientific reasoning. My aim is to inte grate philosophical, cognitive, and computational issues, while also discuss ing some cases of reasoning in science and medicine. The main thesis is that abduction is a significant kind of scientific reasoning, helpful in delineating the first principles of a new theory of science. The status of abduction is very controversial. When dealing with abduc tive reasoning misinterpretations and equivocations are common. What are the differences between abduction and induction? What are the differences between abduction and the well-known hypothetico-deductive method? What did Peirce mean when he considered abduction a kind of inference? Does abduction involve only the generat ion of hypotheses or their evaluation too? Are the criteria for the best explanation in abductive reasoning epis temic, or pragmatic, or both? How many kinds of abduction are there? The book aims to increase knowledge about creative and expert infer ences. The study of these high-level methods of abductive reasoning is situ ated at the crossroads of philosophy, epistemology, artificial intel1igence, cognitive psychology, and logic; that is, at the heart of cognitive science. Philosophers of science in the twentieth century have traditionally distin guished between the inferential processes active in the logic of discovery and the ones active in logic of justification. Most have concluded that no logic of creative processes exists and, moreover, that a rational model of discovery is impossible. In short, scientific creative inferences are irrational and there is no "reasoning" to hypotheses (chapter I) . On the other hand, some research in the area of artificial intelligence has shown that methods for discovery could be found that are computationally adequate for rediscovering - or dis covering for the first time - empirical or theoretical laws and theorems (chapter 2). Moreover, the study of diagnostic (chapter 4), visual, spatial, analogical, and temporal reasoning (chapter 5) has demonstrated that there are many ways of performing intelligent and creative reasoning that cannot be described with only the help of classical logic. However, non-standard xi XII Prefa ce
logic has shown how we ca n provide rigorous formal models of man y kinds of abductive reasoning such as the ones involved in defeasible and uncertain inferences (chapter 2). Contradicti ons and inconsistencies are funda mental in abductive reason ing, and abductive reasoning is appropriate for "governing" inconsistencies . Many ways of gove rning inconsistencies will be considered (chapter 6), from the meth ods activa ted in diagn ostic settings and consistency-based models to the typical ones embedded in so me forms of creative reasoning, from the interpretations in terms of conflicts and competitions to the actions performed on empirical and conceptual anomalies, from the question of gen- . era ting inconsistencies by radica l innovation to the connectionist treatment of co herence. The interdisciplinary character of abduction is central and its fertility in variou s areas of research evident. The book also addr esses the central epis temological question of hypothesis withdrawal in science by discussing his torical cases (chapter 7), where abductive inferences exhibit their most ap pealing cognitive virtu es. Abdu ction is also useful in describ ing the different roles played by the var ious kind s of medical reaso ning, from the point of view both of human agents and of computational programs that perform medical tasks such as diagnosis (chapter 4). Finally, an interesting and neglected point of contenti on about human reasoning is whether or not concrete manipulations of external objects influ ence the genera tion of hypotheses, for exa mple in science. I will delineate the first features of what I ca ll manipulative abduction, showing how we can find methods of co nstructivity in scientific and everyday reasoning based on externa l models and "episternic med iators" (chapter 3). Dur ing the period in which this book was written, I was Visiti ng Profes sor of Philosophy of Science at Georgia Institut e of Technology, Atlanta, which provided an exce llent worki ng environment. I am grateful to my col leagues there at the Co llege of Co mputing and School of Public Policy for their helpful sugges tions and much more. For valuable comments on a pre vious draft I am particularly grateful to Ronald Giere, David Goodin g, Ken neth Knoespel, Nancy Nersessian, Paul Thagard, and two anonymous refe rees. Special thanks to Nancy Nersessian and Paul Thagard, who in the last ten years played a significant role in shaping my ideas and in helping me to focus and articulate my views. The research related to this volume was supported by gra nts from the Italian Mini stry of University, University of Pavia , CNR (Centro Nazionale delle Ricerche), CARIPLO(Cas sa di Risparmi o delle Provincie Lornbarde), and Ivan Allen College (Geo rgia Institute of Technology). The preparation of the volume would not have been possible without the contribution of re sources and facilities of the Co mputational Philosophy Laboratory (Depart- Preface X111 ment of Philosophy, University of Pavia), and of Georgia Institute of Tech nology. This project was conceived as a whole, but as it developed various parts have become articles, which have now been excerpted , revised, and inte grated into the current text. I am grateful to the respective publishers for permission to include portions of previously published articles.
Magnani, L., forthcoming, Creative abduction and hypothesis withdrawal in science, in: Methodological Aspects ofDiscovery and Creativity, J. Meheus and T. Nickles, eds ., Klu wer , Dordrecht. Magnani, L., 1999, Creations and discoveries in science: the role of abductive reasoning, in: Human and Machine Perception 1/: Emergence, Attention, ami Creativity, V. Cantoni, V. Di Gesu, A Setti, and A. Tegolo, eds., Kluwer Academic/Plenum Publishers, New York , pp.137-149. Magnani, L., 1999, Model-based creative abduction, in: Model-Based Reasoning in Scientific Discovery , L. Magnani, N. 1. Nersessian, and P. Thagard, eds., Kluwer Academic/Plenum Publishers, New York , pp. 219-238. Magnani, L., 1999, Withdrawing unfalsifiable hypotheses, Foundations of Science 4(2) :133 153. Magnani, L. 1997, Basic science reasoning and clinical reasoning intertwined: epistemologi cal analysis and consequences for medical education, Advances in Health Sciences Educa tion 2: 115-130. Magnani, L., Chella, A , and da Fontoura Costa, L., 1999, Symbol ism and connectionism paradigms, in: Human and Machine Perception 1/: Emergence, Attention, and Creativity, V. Cantoni, V. Di Gesu , A Setti , and A Tegolo, eds. , Kluwer Academic/Plenum Publish ers, New York, pp. 185-194. Magnani, L. Civita, S., and Previde Massara, G., 1994, Visual cognition and cognitive mod eling, in: Human and Machine Vision: Analogies and Divergences, V. Cantoni, cd., Ple num Press, New York , pp. 229-243.
Lorenzo Magnani University of Pavia, Pavia, Italy Georgia Institute of Technology, Atlanta, GA, Contents
Chapter 1 Hypothesis Generation 1
1. Remini scence, tacit knowledge, schematism I 2. Generate and test 11
Chapter 2 Theoretical Abduction 15
I. What is abduction ? 15 1.1 Abduction and retroduction 15 1.2 ST-MODEL and the syllogistic framework 17 1.3 Abduction as hypothe sis generation, abduction as hypothesis generation and evaluation 25 2. The sentential framework 29 2.1 Abduction and induction in logic programming 36 3. Model-based creative abduction 38 3.1 Conceptual change and creative reasoning in science 38 3.2 Model-based abduction 41 4. Model-based heuristic and deductive reasoning 47 5. Automat ic abductive scienti sts 49
Chapter 3 Manipulative Abduction 53
I. Manipulative abduction in scientific discovery 53 2. Epistemic mediators and manipulative reasoning 59 3. Segregated knowledge and the "world of paper" 63 4. Non-conceptual and spatial abilities 67
xv X VI Cont ents
Chapter 4 Diagnostic Reasonin g 71
1. Is medical reasoning abductive? 72 2. Cognitive models 77 3. The need for an epistemological architecture of medical KBSs 82 4. NEOANEMIA 85 5. Basic science reasoning and clinical reasoning intertwined 88 6.Cognitive models and medical education 92 7. The centrality of abduction 94
Chapter 5 Visual and Temporal Abduction 97
1. Visual abduction 97 1.1Visual imagery 97 1.2 Knowledge representation scheme 98 1.3 Imagery and problem-solving 105 1.4 Visual abduction 106 2. Temporal abduction 115 2.1 Tempora l reference 115 2.2 Science and time: the forgotten dimension 116 2.3 Computational philosophy of time 119
Chapter 6 Governin g Inconsistencies 125
1. Roads to changes in theoretical systems 125 2. Governing inconsistencies in abductive reasoning 129 2.1 Finding inconsistencies I: empiric al anomalies 130 2.2 Finding inconsistencies II: conceptual anomalie s 133 2.3 Generating inconsistencies by radical innovation 135 2.4 Maintaining inconsistencies 136 2.5 Contradicting, conflicting, failing 138 2.6 Inconsistencies and narrative abduction 139 3. Preinventive forms, disconfirming evidence, unexpected findings 140
Chapter 7 Hypothesis Withdrawal in Science 145
1. Withdrawing unfalsifiable hypotheses 145 1.1 Negatio n as failure in query evaluation 146 1.2 Withdrawing constructions 149 1.3 Withdrawing conventions 156 2. Theoretical anoma ly resolution 162 2.1 Scientific concept formation and spatial thinking 162 Contents XVII
2.2 Anomaly resolution and spatial reasoning 163
References 171
Author Index 191
Subject Index 197