Abduction, Reason, and Science
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AI Magazine Volume 23 Number 1 (2002) (© AAAI) Book Reviews been conceptually challenging but al- so shows a (terminological) confusion Book Reviews with its close neighbor, induction. This book contributes to the rapidly growing literature on the topic of ab- ductive reasoning. By placing abduc- Abduction, Reason, and tion at the heart of the foundations of AI from philosophical, cognitive, and computational perspectives, the au- Science: Processes of Discovery thor makes us aware that abduction is not at all a new topic of research. In and Explanation—A Review addition, by introducing fine distinc- tions in abductive kinds, it shows its relevance as a recent topic of research in all these fields. Atocha Aliseda The importance of abduction has been recognized by leading re- searchers in all relevant fields. Al- though for Jaakko Hintikka, abduc- tion is the fundamental problem of roadly speaking, abduction is a his discovery does not work. His helio- contemporary epistemology, in which reasoning process invoked to ex- centric view allowed him to think that abductive inferences are assembled as Bplain a puzzling observation. the sun, so near to the center of the “answers to the inquirer’s explicit or There are however, a variety of differ- planetary system, and so large, must (usually) tacit question put to some ent approaches that claim to capture somehow cause the planets to move as definite source of answers (informa- the true nature of this concept. One they do. In addition to this strong con- tion)” (p. 129), for Herbert Simon, the reason for this diversity lies in the fact jecture, he also had to generalize his nature of the retroductive process (an- that abductive reasoning occurs in a findings for Mars to all planets by as- other term for abduction) “is the main multitude of contexts. It concerns cases suming that the same physical condi- subject of the theory of problem solv- that cover the simplest selection of al- tions could be obtained throughout ing” (p. 16). For Paul Thagard, several ready existing hypotheses to the gener- the solar system. kinds of abduction play a key role as ation of new concepts in science. It also Research on abduction in AI dates heuristic strategies in the program PI (for “processes of induction”), a work- concerns cases where the observation is back to the 1970s, but it is only fairly puzzling because it is novel versus cases ing system devoted to explaining in in which the surprise concerns an computational terms the main prob- lems of philosophy of science, such as anomalous observation. For example, if Abduction, Reason, and Science: Pro- we wake up, and the lawn is wet, we cesses of Discovery and Explanation, scientific discovery, explanation, and might explain this observation by as- Lorenzo Magnani, New York, evaluation (p. 49). suming that it must have rained or that Kluwer Academic/Plenum Pub- In agreement with other current ap- the sprinklers have been on. This is a lishers, 2001, 205 pages, ISBN 0- proaches to abduction, for the author practical setting found in our day-to- 306-46514-0 (hardback). of this book, there are two main episte- day commonsense reasoning when a mological meanings of the word ab- novel phenomenon is needed for an duction: (1) abduction that only gener- recently that it has attracted great in- explanation. Abduction also occurs in ates plausible hypotheses and (2) ab- terest in areas such as logic program- more theoretical scientific contexts. For duction as inference to the best ming, knowledge assimilation, and di- example, it has been claimed (Hanson explanation that also evaluates them 1961; Peirce 1958) that Johannes Ke- agnosis. It has been a topic of several to further obtain the best one. In this pler’s great discovery that the orbit of workshops at AI conferences (1996, book, the first meaning is further divid- the planets is elliptical rather than cir- 1998, 2000 European Conference on ed into selective or creative. Selection cular was a prime piece of abductive Artificial Intelligence; 1997 Interna- takes place in contexts such as medical reasoning. What initially led to this dis- tional Joint Conference on Artificial diagnosis, in which the task is to select covery was his anomalous observation Intelligence) as well as model-based a diagnosis from a precompiled set of that the longitudes of Mars did not fit reasoning conferences (1998, 2001 diagnostic entities. Creativity is present circular orbits. Moreover, before even Model-Based Reasoning Conference). in issues such as the discovery of a new dreaming that the best explanation in- It has also been at the center of recent disease. The latter meaning, abduction volved ellipses instead of circles, he publications (Flach and Kakas 2000; as inference to the best explanation, is tried several other forms. Kepler had to Josephson and Josephson 1994). In all described by the complete abduction- make some other assumptions about these places, the discussion about the deduction-induction cycle, represented the planetary system, without which different aspects of abduction has in an epistemological model for diag- Copyright © 2002, American Association for Artificial Intelligence. All rights reserved. 0738-4602-2002 / $2.00 SPRING 2002 113 Book Reviews nostic reasoning (ST-MODEL) in which se- necessarily sentential or formal). of the chapters are dedicated to the lective abduction introduces a set of This book presents as well applica- analysis of the role of inconsistencies plausible hypotheses, followed by de- tions of the several distinctions of ab- in scientific discovery (chapter 6) and duction to explore their consequences duction introduced earlier. For exam- the makeup of hypotheses withdrawal and induction to test them, to either ple, the case of medical diagnostic rea- in science (chapter 7). increase their likelihood or refute all soning is described as an instance of Abduction, Reason, and Science is a but one. Even though the selection and theoretical abduction, showing that its book for those interested in the sub- evaluation phases of abduction are in machinery fits the epistemological ject of discovery who are willing to get fact integrated in cognitive models of model mentioned earlier; the patient an integrated picture from philoso- human thought, it is nevertheless a data are abstracted and used to select phy, cognitive science, and computer useful methodological distinction for hypotheses, and these hypothetical so- science, all disciplines concerned with the development of real artificial rea- lutions in turn provide starting condi- the question of creative reasoning. A soning systems. tions for the forecast of expected conse- beginner can get a pretty good idea of Moreover, Magnani proposes an in- quences, which are later compared to the recent status of research on abduc- teresting distinction between theoret- the patient’s data to evaluate (corrobo- tion, and at the same time, it pleases ical abduction and manipulative ab- rate or eliminate) those hypotheses the expert by informing him/her duction. Although theoretical abduc- that come from deduction. A particular about approaches in other fields and tion “is the process of reasoning in application is the system NEOANEMIA, a offering a detailed and interesting no- which explanatory hypotheses are working diagnostic system for disorders tice about the original views of its au- formed and evaluated” (p. 18), and such as anemia developed at the home thor, Lorenzo Magnani. can, in turn, be sentential or model university of the author (Pavia). Visual I found it interesting that the ST-MOD- based (to be explained later), manipu- and temporal aspects of abduction are EL resembles the American pragmatist lative abduction is action based, the also taken into account and presented Charles S. Peirce’s complete framework case in which “the suggested hypothe- as cases of model-based creative abduc- of abduction, which considers not only ses are inherently ambiguous until ar- tion. This perspective highlights the its inferential logical structure (which is ticulated into configurations of real or importance of both spatial reasoning what most approaches take) but also “imaginated” [SIC] entities (p. 54). and anomaly resolution for hypotheses two further aspects, namely, (1) testing The interplay of these two aspects generation and scientific discovery. The and (2) economy. I think that it has be- “consists of a superimposition of inter- concrete example is the discovery of come quite clear by now—and this nal and external, where the elements non-Euclidean geometries, about book makes a strong point in this direc- of the external structures gain new which it is argued that some of the hy- tion —that the study of the role of test- meanings and relationships to one an- potheses created by Lobachevsky were ing in abduction is fundamental for its other, thanks to the constructive ex- indeed image based, something that understanding. planatory theoretical activity” (p. 59). helped to deal with the fifth parallel References Magnani offers an impressive and postulate by manipulation of symbols. comprehensive overview of the logical Interestingly, the author claims that Flach, P., and Kakas, A., eds. 2000. Abduc- approaches to abduction, covering the the anomalous (or problematic) aspect tive and Inductive Reasoning: Essays on Their Relation and Integration. Applied Logic Se- deductive model, the abductive logic of the Euclidean fifth postulate lies in ries. New York: Kluwer Academic. programming paradigm, and ap- that “we cannot draw or ‘imagine’ the Hanson, N. R. 1961. Patterns of Scientific proaches linking abduction to the two lines at infinity” (p. 165), which, in Discovery. Cambridge, U.K.: Cambridge well-known framework of belief revi- contrast to the rest of the postulates, is University Press. sion, all of which are considered as empirically unverifiable and, thus, Josephson, J., and Josephson, S., eds. 1994. cases of theoretical sentential abduc- opens the door to the possibility of cre- Abductive Inference: Computation, Philosophy, tion, given their logical character.