The coherence of independent reports provides a strong reason to believe that the reports are true. This plausible claim has come under attack from recent work in Bayesian epistemology. This work shows that, under certain probabilistic conditions, coherence cannot increase the probability of the target claim. These theorems are taken to demonstrate that epistemic coherentism is untenable. To date no one has investigated how these results bear on different conceptions of coherence. I investigate this situation using Thagard’s (...) ECHO model of explanatory coherence. Thagard’s ECHO model provides a natural representation of the evidential significance of multiple independent reports. (shrink)

This target article presents a new computational theory of explanatory coherence that applies to the acceptance and rejection of scientific hypotheses as well as to reasoning in everyday life, The theory consists of seven principles that establish relations of local coherence between a hypothesis and other propositions. A hypothesis coheres with propositions that it explains, or that explain it, or that participate with it in explaining other propositions, or that offer analogous explanations. Propositions are incoherent with each (...) other if they are contradictory, Propositions that describe the results of observation have a degree of acceptability on their own. An explanatory hypothesis is acccpted if it coheres better overall than its competitors. The power of the seven principles is shown by their implementation in a connectionist program called ECHO, which treats hypothesis evaluation as a constraint satisfaction problem. Inputs about the explanatory relations are used to create a network of units representing propositions, while coherende and incoherence relations are encoded by excitatory and inbihitory links. ECHO provides an algorithm for smoothly integrating theory evaluation based on considerations of explanatory breadth, simplicity, and analogy. It has been applied to such important scientific cases as Lovoisier's argument for oxygen against the phlogiston theory and Darwin's argument for evolution against creationism, and also to cases of legal reasoning. The theory of explanatory coherence has implications for artificial intelligence, psychology, and philosophy. (shrink)

During the latter part of the nineteenth century our description of nerve cell structure underwent a relatively unrecognized, though fundamental, transformation-a quiet revolution of sorts. The central problem facing scientists in neurology (the study of the nervous system) was a related pair: are nerve cells continuous with each other or not, and how is information conducted? Microscope resolution and staining techniques were inadequate at the time to yield definitive proof either way. I contend that explanatory coherence provides a (...) means to elucidate this instance of theory change in the history of science. The means of elucidation will be Thagard's computational model of explanatory coherence, ECHO (). (shrink)

Classical models of decision making deal fairly well with uncertainty, where settings are well-structured in terms of goals, alternatives, and consequences. Conversely, the typical ill-structured nature of strategy choices remains a challenge for extant models. Such cases can hardly build on the past, and their novelty makes the prediction of consequences a very difficult and poorly robust task. The weakness of the classical expected utility model in representing such problems has not been adequately solved by recent extensions. In this paper (...) we offer an explanatory coherence model for decision making in ill-structured problems. We model alternatives as sets of concurrent causal explanations of reality that act as justifications for action. According to these premises, choice is based on an evaluation of the internal coherence and the consistency of competing explanations of the available evidence. This model is psychologically grounded on causal inference and builds on the connectionist tradition of explanatory coherence. To illustrate the model, we consider the decision of investing in a new technology and we discuss how changes in the structure of alternatives may impact on the solution. We show how the final choice depends on collecting the relevant evidence, making the suitable hypotheses, and drawing the consistent causal explanations linking the two. (shrink)

This paper applies a new theory of explanatory coherence to the early history of the idea of continental drift. The new theory consists of seven principles that establish coherence and incoherence relations among propositions. It has been implemented in a connectionist computer program called ECHO. Analysis of the arguments of Alfred Wegener, the first major proponent of continental drift, provided input to ECHO which evaluated the explanatory coherence of his hypotheses. ECHO has also been used (...) to analyze the coherence of the views of Wegener 's critics. The paper concludes by contrasting our explanatory coherence account of Wegener and his opposition with a decision-theoretic account recently offered by Ron Giere. (shrink)

In the nineteen-sixties, plate tectonics became the accepted theoretical framework in the earth sciences. This framework revived the idea of continental drift that had been first proposed in 1912 by Alfred Wegener (1966). This paper offers an analysis of the arguments of Wegener and his opponents. We shall show that from Wegener’s perspective his hypotheses possessed a high degree of explanatory coherence, while from the opponents’ perspective his theory was incoherent with much that was generally known.Our analysis uses (...) a new theory of explanatory coherence that has already been applied to several important cases in the history of science: Lavoisier’s argument for his oxygen theory against the phlogiston theory, Darwin’s argument for the theory of evolution by natural selection, and current disputes about why dinosaurs became extinct (Thagard 1988b). This theory is implemented in a connectionist computer program called ECHO that takes statements of explanatory relations as input and creates a network of units, crudely analogous to neurons, with excitatory and inhibitory links among them. (shrink)

Statements that share an explanation tend to lend inductive support to one another. For example, being told that Many furniture movers have a hard time financing a house increases the judged probability that Secretaries have a hard time financing a house. In contrast, statements with different explanations reduce one another s judged probability. Being told that Many furniture movers have bad backs decreases the judged probability that Secretaries have bad backs. I pose two questions concerning such discounting effects. First, does (...) the reduction depend on explanations being mutually incompatible or does it occur when explanations are deemed irrelevant to one another? I found that a small discounting effect occurred with statements that were blatantly unrelated. However, the discounting effect also depended on a factor external to the argument being judged; the composition of the argument set. Second, are explanation effects attributable to changes in the belief afforded statements or to response-specific changes resulting from misunderstanding of the probability rating task or response bias? The results implicate changes in belief. Prior belief influenced conditional probability more than argument strength judgements, as it would if participants understood the tasks in the same way as the experimenter. Also, conditional probability true and false judgements were complementary, suggesting no response bias. (shrink)

This paper develops a descriptive and normative account of how people respond to testimony. It postulates a default pathway in which people more or less automatically respond to a claim by accepting it, as long as the claim made is consistent with their beliefs and the source is credible. Otherwise, people enter a reflective pathway in which they evaluate the claim based on its explanatory coherence with everything else they believe. Computer simulations show how explanatory coherence (...) can be maximized in real-life cases, taking into account all the relevant evidence including the credibility of whoever is making a claim. The explanatory-coherence account is more plausible both descriptively and normatively than a Bayesian account. (shrink)

Peter Achinstein (1990, 1991) analyses the scientific debate that took place in the eighteenth and nineteenth centuries concerning the nature of light. He offers a probabilistic account of the methods employed by both particle theorists and wave theorists, and rejects any analysis of this debate in terms of coherence. He characterizes coherence through reference to William Whewell's writings concerning how "consilience of inductions" establishes an acceptable theory (Whewell, 1847) . Achinstein rejects this analysis because of its vagueness and (...) lack of reference to empirical data, concluding that coherence is insufficient to account for the belief change that took place during the wave-particle debate. (shrink)

In a series of articles, Paul Thagard has developed a connectionist''s modelfor the evaluation of explanatory coherence for competing systems ofhypotheses. He has successfully applied it to various examples from thehistory of science and common language reasoning. However, I will argue thathis formalism does not adequately represent explanatory relations betweenmore than two propositions.In this paper, I develop a generalization of Thagard''s approach. It is notsubject to the connectionist paradigm of neural nets, but is based on fuzzylogic: (...) class='Hi'>Explanatory coherence increases with the fuzzy truth value of theconjunction of explanans and explanandum and decreases with the value of theconjunction of explanans and the negation of the explanandum. (shrink)

Foundationalist theories of justification for science were undermined by the theory-ladeness thesis, which has affinities with coherentist epistemologies. A challenge for defenders of coherentist theories of scientific justification is to specify coherence relations relevant to science and to show how these relations make the truth of their bearers likely. Coherence relations include characteristics that pick out better explanations in the implementation of abductive arguments. Empiricist philosophers have attacked abductive reasoning by claiming that explanatory virtues are pragmatic, having (...) no implications regarding truth. However, empiricist's basic beliefs are subject to the same challenges facing abduction, both of which can be met by citing causally coherent etiologies, which are commonplace in biological explanations, and by demonstrating the relevance of causal coherence to truth. (shrink)

Reasoning by jurors concerning whether an accused person should be convicted of committing a crime is a kind of casual inference. Jurors need to decide whether the evidence in the case was caused by the accused’s criminal action or by some other cause. This paper compares two computational models of casual inference: explanatory coherence and Bayesian networks. Both models can be applied to legal episodes such as the von Bu¨low trials. There are psychological and computational reasons for preferring (...) the explanatory coherence account of legal inference. (shrink)

When surprising events occur, people naturally try to generate explanations of them. Such explanations usually involve hypothesizing causes that have the events as effects. Reasoning from effects to prior causes is found in many domains, including: Social reasoning: when friends are acting strange, we conjecture about what might be bothering them. Legal reasoning: when a crime has been committed, jurors must decide whether the prosecution's case gives a convincing explanation of the evidence. Medical diagnosis: given a set of symptoms, a (...) physician tries to decide what disease or diseases produced them. Fault diagnosis in manufacturing: when a piece of equipment breaks down, a trouble shooter must try to determine the cause of the breakdown. Scientific theory evaluation: scientists seek an acceptable theory to explain experimental evidence. What is the nature of such reasoning? (shrink)

According to the truth-conduciveness problem of coherentism, the coherence theory of justification can hardly show that coherentist justification is truth-conducive. This problem is generally conceived as the most recalcitrant problem with the coherence theory. The purpose of this paper is to show that it does not pose a serious problem for a certain version of coherentism, namely a Sellarsian explanatory coherence theory of justification combined with the deflationary theory of truth. On this version of coherentism, our (...) epistemic goal is to gradually improve our conceptual framework so as to maximize its explanatory coherence, and there is no substantial norm of truth independent of the norms of justification, so that we cannot evaluate the truth-conduciveness of a belief independently of the norms of justification. I argue that this version of coherentism can cope with the truth-conduciveness problem. (shrink)

In adversarial problem solving (APS), one must anticipate, understand and counteract the actions of an opponent. Military strategy, business, and game playing all require an agent to construct a model of an opponent that includes the opponent's model of the agent. The cognitive mechanisms required for such modeling include deduction, analogy, inductive generalization, and the formation and evaluation of explanatory hypotheses. Explanatory coherence theory captures part of what is involved in APS, particularly in cases involving deception.

The likelihood of a statement is often derived by generating an explanation for it and evaluating the plausibility of the explanation. The explanation discounting principle states that people tend to focus on a single explanation; alternative explanations compete with the effect of reducing one another’s credibility. Two experiments tested the hypothesis that this principle applies to inductive inferences concerning the properties of everyday categories. In both experiments, subjects estimated the probability of a series of statements and the conditional probabilities of (...) those conclusions given other related facts. For example, given that most lawyers make good sales people, what is the probability that most psychologists make good sales people? The results showed that when the fact and the conclusion had the same explanation the fact increased people’s willingness to believe the conclusion, but when they had different explanations the fact decreased the conclusion’s credibility. This decrease is attributed to explanation discounting; the explanation for the fact had the effect of reducing the plausibility of the explanation for the conclusion. (shrink)

This article generalizes the explanationist account of inference to the best explanation. It draws a clear distinction between IBE and abduction and presents abduction as the first step of IBE. The second step amounts to the evaluation of explanatory power, which consist in the degree of explanatory virtues that a hypothesis exhibits. Moreover, even though coherence is the most often cited explanatory virtue, on pain of circularity, it should not be treated as one of the (...) class='Hi'>explanatory virtues. Rather, coherence should be equated with explanatory power and considered to be derivable from the other explanatory virtues: unification, explanatory depth and simplicity. (shrink)

Proponents of IBE claim that the ability of a hypothesis to explain a range of phenomena in a unifying way contributes to the hypothesis’s credibility in light of these phenomena. I propose a Bayesian justification of this claim that reveals a hitherto unnoticed role for explanatory unification in evaluating the plausibility of a hypothesis: considerations of explanatory unification enter into the determination of a hypothesis’s prior by affecting its ‘explanatory coherence’, that is, the extent to which (...) the hypothesis offers mutually cohesive explanations of various phenomena. (shrink)

What is the relation between coherence and truth? This paper rejects numerous answers to this question, including the following: truth is coherence; coherence is irrelevant to truth; coherence always leads to truth; coherence leads to probability, which leads to truth. I will argue that coherence of the right kind leads to at least approximate truth. The right kind is explanatory coherence, where explanation consists in describing mechanisms. We can judge that a scientific (...) theory is progressively approximating the truth if it is increasing its explanatory coherence in two key respects: broadening by explaining more phenomena and deepening by investigating layers of mechanisms. I sketch an explanation of why deepening is a good epistemic strategy and discuss the prospect of deepening knowledge in the social sciences and everyday life. (shrink)

The article advocates a particular coherence theory of justification that emphasizes the significance of explanatory relations. It is shown that other approaches to coherence have failed because they underestimate the importance of explanatory theories in forming a system of beliefs. Additionally, a conception of explanation as a unifying substantial embedding of models is sketched that closely conforms with the proposed theory of coherence.

Abductive reasoning assigns special status to the explanatory power of a hypothesis. But how do people make explanatory judgments? Our study clarifies this issue by asking: How does the explanatory power of a hypothesis cohere with other cognitive factors? How does probabilistic information affect explanatory judgments? In order to answer these questions, we conducted an experiment with 671 participants. Their task was to make judgments about a potentially explanatory hypothesis and its cognitive virtues. In the (...) responses, we isolated three constructs: Explanatory Value, Rational Acceptability, and Entailment. Explanatory judgments strongly cohered with judgments of causal relevance and with a sense of understanding. Furthermore, we found that Explanatory Value was sensitive to manipulations of statistical relevance relations between hypothesis and evidence, but not to explicit information about the prior probability of the hypothesis. These results indicate that probabilistic information about statistical relevance is a strong determinant of Explanatory Value. More generally, our study suggests that abductive and probabilistic reasoning are two distinct modes of inference. (shrink)

William Lycan's On Evidence in Philosophy makes noteworthy contributions to many important philosophical topics. The topics discussed here are epistemic justification by explanatory coherence, seeming truths as sources of initial justification, the extent of our philosophical ignorance, the fault in begging the question, the nature of intuitions, and the evidence that intuitions supply. For each topic, an attempt is made to employ work done in the book to advance the philosophical issues.

Recently there have been several attempts in formal epistemology to develop an adequate probabilistic measure of coherence. There is much to recommend probabilistic measures of coherence. They are quantitative and render formally precise a notion—coherence—notorious for its elusiveness. Further, some of them do very well, intuitively, on a variety of test cases. Siebel, however, argues that there can be no adequate probabilistic measure of coherence. Take some set of propositions A, some probabilistic measure of coherence, (...) and a probability distribution such that all the probabilities on which A’s degree of coherence depends (according to the measure in question) are defined. Then, the argument goes, the degree to which A is coherent depends solely on the details of the distribution in question and not at all on the explanatory relations, if any, standing between the propositions in A. This is problematic, the argument continues, because, first, explanation matters for coherence, and, second, explanation cannot be adequately captured solely in terms of probability. We argue that Siebel’s argument falls short. (shrink)

In this new explanationist account of epistemic justification, Poston argues that the explanatory virtues provide all the materials necessary for a plausible account of justified belief. There are no purely autonomous reasons. Rather reasons occur only within an explanatory coherent set of beliefs.

Structural and functional descriptions of technical artefacts play an important role in engineering practice. A complete description of a technical artefact involves a description of both functional and structural features. Engineers, moreover, assume that there is an intimate relationship between the function and structure of technical artefacts and they reason from functional properties to structural ones and vice versa. This raises the question of how structural and functional descriptions are related. The kind of inference patterns that establish coherence between (...) structural and functional descriptions are explored in this paper, using the analysis of coherence creating relations of Thagard et al. Explanatory, analogical and practical inference patterns are discussed and it is argued that of these three, practical inferences may be the most important. Practical inferences, however, cannot provide a full underpinning of the coherence of structural and functional descriptions of technical artefacts. The paper ends with the suggestion that any account of the coherence of the structural and functional descriptions of technical artefacts must involve reference to their intentional features.Keywords: Technical artefact; Structural description; Functional description; Coherence relation; Practical inference. (shrink)

This paper explores cosmopsychism’s explanatory aspirations from a programmatic perspective. The bulk of the text consists of an argument in favor of the conclusion that cosmopsychism suffers from no insurmountable individuation problem. I argue that the widespread tendency to view IND as a mirror-image of micropsychism’s combination problem is mistaken. In particular, what renders CP insolvable, namely, the commitment to the coupling of phenomenal constitution with phenomenal inclusion, is, from the standpoint of cosmopsychism, an entirely nonmandatory assumption. I proceed (...) to show that severing this unhappy coupling is the key for defending cosmopsychism against the charge of theoretical incoherence. Moreover, I argue that successful defense against such accusation could be mounted regardless of whether or not we assume cosmic consciousness to be perspectival in nature. In addition, the paper touches upon another foundational issue: cautioning against the popular tendency to identify cosmopsychism’s monism with a mereological unity-in-diversity, and motivating an alternative conception which I call generative monism. Finally, as befitting this volume, I pause to reflect upon the question of which schools of Hindu philosophy might tally best, and connect most fruitfully, with cosmopsychism as I understand it. (shrink)

This paper represents a response to the criticisms made by Eric Barnes in “Explanatory Unification and the Problem of Asymmetry” and “Explanatory Unification and Scientific Understanding” against the thesis of Explanatory Unification. This paper responds to Barnes‟ two main criticisms, that of derivational skepticism and causal asymmetry, and successfully refutes his objections. This paper also defends the plausibility of the unificationist account of scientific explanation because of its ability to render coherent the notion of scientific understanding, focusing (...) in particular on the work by Michael Friedman and Philip Kitcher. (shrink)