This paper provides new tools for philosophical argument analysis and fresh empirical foundations for ‘critical’ ordinary language philosophy. Language comprehension routinely involves stereotypical inferences with contextual defeaters. J.L. Austin’s Sense and Sensibilia first mooted the idea that contextually inappropriate stereotypical inferences from verbal case-descriptions drive some philosophical paradoxes; these engender philosophical problems that can be resolved by exposing the underlying fallacies. We build on psycholinguistic research on salience effects to explain when and why even perfectly competent speakers cannot help making (...) stereotypical inferences which are contextually inappropriate. We analyse a classical paradox about perception, suggest it relies on contextually inappropriate stereotypical inferences from appearance-verbs, and show that the conditions we identified as leading to contextually inappropriate stereotypical inferences are met in formulations of the paradox. Three experiments use a forced-choice plausibility-ranking task to document the predicted inappropriate inferences, in English, German, and Japanese. The cross-linguistic study allows us to assess the wider relevance of the proposed analysis. Our findings open up new perspectives for ‘evidential’ experimental philosophy. (shrink)

The notions of inference and default are used in pragmatics with different meanings, resulting in theoretical disputes that emphasize the differences between the various pragmatic approaches. This paper is aimed at showing how the terminological and theoretical differences concerning the two aforementioned terms result from taking into account inference and default from different points of view and levels of analysis. Such differences risk making a dialogue between the theories extremely difficult. However, at a functional level of (...) analysis the different theories, definitions, and approaches to interpretation can be compared and integrated. At this level, the standardization of pragmatic inferences can be regarded as the development of a specific type of presumptions, used to draw prima-facie interpretations. (shrink)

It is a fact that human subjects rate sentences about typical properties such as “Ravens are black” as very likely to be true. In comparison, modified sentences such as “Feathered ravens are black” receive lower ratings, especially if the modifier is atypical for the noun, as in “Jungle ravens are black”. This is called themodifier effect. However, the likelihood of the unmodified statement influences the perceived likelihood of the modified statement: the higher the rated likelihood of the unmodified sentence, the (...) higher the rated likelihood of the modified one. That means the modifier effect does not fully blockdefault inheritanceof typical properties from nouns to modified nouns. This paper discusses this inheritance effect. In particular, I ask whether it is the direct result of composing concepts from nouns, that is, a bias toward “black” when processing “raven”. I report a series of experiments in which I find no evidence for a direct inheritance from composition. This supports the view that default inheritance is rather an inference than a bias. (shrink)

The underconsideration argument against inference to the best explanation and scientific realism holds that scientists are not warranted in inferring that the best theory is true, because scientists only ever conceive of a small handful of theories at one time, and as a result, they may not have considered a true theory. However, antirealists have not developed a detailed alternative account of why explanatory inference nevertheless appears so central to scientific practice. In this paper, I provide new defences (...) against some recent objections to the underconsideration argument, while also developing an account of explanatory inference that both survives these criticisms and does not entail realism. (shrink)

Since its inception, situation theory has been concerned with the situated nature of meaning and cognition, a theme which has also recently gained some prominence in Artificial Intelligence. Channel theory is a recently developed framework which builds on concepts introduced in situation theory, in an attempt to provide a general theory of information flow. In particular, the channel theoretic framework offers an account of fallible regularities, regularities which provide enough structure to an agent's environment to support efficient cognitive processing but (...) which are limited in their reliability to specific circumstances. This paper describes how this framework can lead to a different perspective on defeasible reasoning: rather than being seen as reasoning with incomplete information, an agent makes use of a situated regularity, choosing to use the regularity that seems best suited (trading off reliability and simplicity) to the circumstances it happens to find itself in. We present a formal model for this task, based on the channel theoretic framework, and sketch how the model may be used as the basis for a methodology of defeasible situated reasoning, whereby agents reason with simple monotonic regularities but may revise their choice of regularity on learning more about their circumstances. (shrink)

Based on a close study of benchmark examples in default reasoning, such as Nixon Diamond, Penguin Principle, etc., this paper provides an in depth analysis of the basic features of default reasoning. We formalize default inferences based on Modus Ponens for Default Implication, and mark the distinction between "local inferences"(to infer a conclusion from a subset of given premises) and "global inferences"(to infer a conclusion from the entire set of given premises). These conceptual analyses are captured (...) by a formal semantics that is built upon the set-selection function technique. A minimal logic system M of default reasoning that accommodates Modus Ponens for Default Implication and suitable for local inferences is proposed, and its soundness is proved. (shrink)

There are numerous formal systems that allow inference of new conditionals based on a conditional knowledge base. Many of these systems have been analysed theoretically and some have been tested against human reasoning in psychological studies, but experiments evaluating the performance of such systems are rare. In this article, we extend the experiments in [19] in order to evaluate the inferential properties of c-representations in comparison to the well-known Systems P and Z. Since it is known that System Z (...) and c-representations mainly differ in the sorts of inheritance inferences they allow, we discuss subclass inheritance and present experimental data for this type of inference in particular. (shrink)

This paper presents statistical default logic, an expansion of classical (i.e., Reiter) default logic that allows us to model common inference patterns found in standard inferential statistics, including hypothesis testing and the estimation of a populations mean, variance and proportions. The logic replaces classical defaults with ordered pairs consisting of a Reiter default in the first coordinate and a real number within the unit interval in the second coordinate. This real number represents an upper-bound limit on (...) the probability of accepting the consequent of an applied default and that consequent being false. A method for constructing extensions is then defined that preserves this upper bound on the probability of error under a (skeptical) non-monotonic consequence relation. (shrink)

A consistency default is a propositional inference rule that asserts the consistency of a formula in its consequence. Consistency defaults allow for a straightforward encoding of domains in which it is explicitely known when something is possible. The logic of consistency defaults can be seen as a variant of cumulative default logic or as a generalization of justified default logic; it is also able to simulate Reiter default logic in the seminormal case. A semantical characterization (...) of consistency defaults in terms of processes and in terms of a fixpoint equation is given, as well as a normal form. (shrink)

Statistical Default Logic (SDL) is an expansion of classical (i.e., Reiter) default logic that allows us to model common inference patterns found in standard inferential statistics, e.g., hypothesis testing and the estimation of a population‘s mean, variance and proportions. This paper presents an embedding of an important subset of SDL theories, called literal statistical default theories, into stable model semantics. The embedding is designed to compute the signature set of literals that uniquely distinguishes each extension on (...) a statistical default theory at a pre-assigned error-bound probability. (shrink)

When reasoning about complex domains, where information available is usually only partial, nonmonotonic reasoning can be an important tool. One of the formalisms introduced in this area is Reiter's Default Logic (1980). A characteristic of this formalism is that the applicability of default (inference) rules can only be verified in the future of the reasoning process. We describe an interpretation of default logic in temporal epistemic logic which makes this characteristic explicit. It is shown that this (...) interpretation yields a semantics for default logic based on temporal epistemic models. A comparison between the various semantics for default logic will show the differences and similarities of these approaches and ours. (shrink)

This article advances the first semantics that is neither for nor against a default implicational link between the progressive and perfective forms, when it comes to solving the imperfective paradox. Depending on the doxastic context of its use, we contend that the progressive form sometimes allows and sometimes does not allow the inference of the corresponding simple form. In other words, the preparatory phase of an event might or might not be believed to lead to its culmination. Indeed, (...) the context can put constraints on beliefs about the time of the culmination and whether or not it allows this inference to be made. From a formal perspective, this new solution to the imperfective paradox combines a specific modal approach with an event-structure analysis originating in event semantics. Finally, this approach solves the associated difficulties that have plagued the most well-known theories in this field. (shrink)

In this pioneering book Kasia Jaszczolt lays down the foundations of an original theory of meaning in discourse, reveals the cognitive foundations of discourse interpretation, and puts forward a new basis for the analysis of discourse processing. She provides a step-by-step introduction to the theory and its application, and explains new terms and formalisms as required. Dr Jaszczolt unites the precision of truth-conditional, dynamic approaches with insights from neo-Gricean pragmatics into the role of speaker's intentions in communication. She shows that (...) the compositionality of meaning may be understood as merger representations combining information from various sources including word meaning and sentence structure, various kinds of default interpretations, and conscious pragmatic inference. Among the applications the author discusses are constructions that pose problems in semantic analysis such as referring expressions, propositional attitude constructions, presupposition, modality, numerals, and sentential connectives. She proposes solutions to cutting edge problems in the semantics/pragmatics interface - for example, how many levels of meaning should be distinguished; the status of underspecification; how much contextual information should be placed in the representation of the speaker's meaning; whether there are default interpretations; the stage of utterance interpretation at which pragmatic inference begins; and whether compositionality is a necessary feature of the theory of meaning and if so how it is to be defined.The book is for students and researchers in semantics, pragmatics, computational linguistics, and philosophy of language at advanced undergraduate level and above. (shrink)

Language employs various coordinators to connect propositions, a subset of which are “logical” in nature and thus analogous to the truth operators of formal logic. We here focus on two linguistic connectives and their negations: conjunction _and_ and (inclusive) disjunction _or_. Linguistic connectives exhibit a truth-conditional component as part of their meaning (their semantics), but their use in context can give rise to various implicatures and presuppositions (the domain of pragmatics) as well as to inferences that go beyond semantic/pragmatic properties (...) (the result of reasoning processes). We provide a comprehensive review of the role of the logical connectives in language and argue that three sets of factors—semantic, pragmatic, and those related to reasoning—are separate and separable, though some details may differ cross-linguistically. As a way to showcase the argument, we present two experiments in language comprehension in Spanish wherein pragmatic content was minimised and reasoning processes neutered, thus potentially highlighting what might be the default meanings of the connectives under study. In Experiment 1 we show that the conjunctive reading of inclusive disjunction is available in positive contexts other than in syntactically intricate cases such as downward entailing and free choice contexts, contrary to what has been claimed in the literature. In Experiment 2 we show that negated conjunctions and disjunctions in Spanish can easily receive the same interpretation when contrasted against the same context and, moreover, that these interpretations match those available in English, despite claims from the literature that linguistic connectives and local negation interact differently in English and Romance languages. (shrink)

This paper argues for the reasonableness of an inclusive conception of default reasoning. The inclusive conception allows untriggered default rules to influence beliefs: Since a default “from φ, infer ψ” is a defeasible inference rule, it by default warrants a belief in the material implication φ → ψ, even if φ is not believed. Such inferences are not allowed in standard default logic of the Reiter tradition, but are reasonable by analogy to the Deduction (...) Theorem for classical logic. Our main contribution is a formal framework for inclusive default reasoning. The framework has a solid philosophical foundation, it draws conclusions non-trivially different from non-inclusive frameworks, and it exhibits a host of benchmark properties deemed desirable in the literature—e.g., that extensions always exist and are consistent. (shrink)

Most of the work in default logic is about default theories that are completely specified. In this category are the proposals of appropriate semantics for default logic, the characterizations of the complexity of reasoning with a default theory, the algorithms for finding consequences of default theories, etc. Relatively little attention has been paid to the process of building a default theory, and most of the work on this topic is about translating knowledge bases from (...) other formalisms (such as circumscription, autoepistemic logic, and action description languages) into default logic. This paper is about expressing knowledge in default logic. In particular, we assume that defaults are initially formulated as normal, and are then corrected using specific inference examples. (shrink)

This article tests human inference rationality when dealing with default rules. To study human rationality, psychologists currently use classical models of logic or probability theory as normative models for evaluating human ability to reason rationally. Our position is that this approach is convincing, but only manages to capture a specific case of inferential ability with little regard to conditions of everyday reasoning. We propose that the most general case to be considered is inference with imperfect knowledge - (...) in the present case restricted to uncertain knowledge - and that a natural framework for testing the rationality of plausible reasoning is System P. This system provides rational postulates for nonmonotonic inference. The semantic of the nonmonotonic inference is given by a possibilistic constraint introduced by Dubois and Prade (1991). This constraint states that a rule p ( q is a plausible rule if "the degree to which p ( q is possible" is greater than "the degree to which p ( (q is possible". Given the choice of this constraint, we study two supplementary postulates of rationality. Eighty-eight subjects participated in an experiment whose results confirm - provided that reflexivity and left logical equivalence would be tested in a further experiment - the rationality of human nonmonotonic inference according to the rational postulates of System P. (shrink)

Default reasoning occurs whenever the truth of the evidence available to the reasoner does not guarantee the truth of the conclusion being drawn. Despite this, one is entitled to draw the conclusion “by default” on the grounds that we have no information which would make us doubt that the inference should be drawn. It is the type of conclusion we draw in the ordinary world and ordinary situations in which we find ourselves. Formally speaking, ‘nonmonotonic reasoning’ refers (...) to argumentation in which one uses certain information to reach a conclusion, but where it is possible that adding some further information to those very same premises could make one want to retract the original conclusion. It is easily seen that the informal notion of default reasoning manifests a type of nonmonotonic reasoning. Generally speaking, default statements are said to be true about the class of objects they describe, despite the acknowledged existence of “exceptional instances” of the class. In the absence of explicit information that an object is one of the exceptions we are enjoined to apply the default statement to the object. But further information may later tell us that the object is in fact one of the exceptions. So this is one of the points where nonmonotonicity resides in default reasoning. (shrink)

This paper presents a formalism that combines useful properties of both logic and probabilities. Like logic, the formalism admits qualitative sentences and provides symbolic machinery for deriving deductively closed beliefs and, like probability, it permits us to express if-then rules with different levels of firmness and to retract beliefs in response to changing observations. Rules are interpreted as order-of-magnitude approximations of conditional probabilities which impose constraints over the rankings of worlds. Inferences are supported by a unique priority ordering on rules (...) which is syntactically derived from the knowledge base. This ordering accounts for rule interactions, respects specificity considerations and facilitates the construction of coherent states of beliefs. Practical algorithms are developed and analyzed for testing consistency, computing rule ordering, and answering queries. Imprecise observations are incorporated using qualitative versions of Jeffrey's rule and Bayesian updating, with the result that coherent belief revision is embodied naturally and tractably. Finally, causal rules are interpreted as imposing Markovian conditions that further constrain world rankings to reflect the modularity of causal organizations. These constraints are shown to facilitate reasoning about causal projections, explanations, actions and change. (shrink)

In his work on the epistemology of testimony, Peter Lipton developed an account of testimonial inference that aimed at descriptive adequacy as well as justificatory sophistication. According to ‘testimonial inference to the best explanation’, we accept what a speaker tells us because the truth of her claim figures in the best explanation of the fact that she made it. In this paper, I argue for a modification of this picture. In particular, I argue that IBE plays a dual (...) role in the management and justification of testimony. On the one hand, the coherence and success of our testimony-based projects provides general abductive support for a default stance of testimonial acceptance; on the other hand, we are justified in rejecting specific testimonial claims whenever the best explanation of the instances of testimony we encounter entails, or makes probable, the falsity or unreliability of the testimony in question.Keywords: Testimony; Inference to the best explanation; Abduction; Epistemic justification. (shrink)

In previous work, we studied four well known systems of qualitative probabilistic inference, and presented data from computer simulations in an attempt to illustrate the performance of the systems. These simulations evaluated the four systems in terms of their tendency to license inference to accurate and informative conclusions, given incomplete information about a randomly selected probability distribution. In our earlier work, the procedure used in generating the unknown probability distribution (representing the true stochastic state of the world) tended (...) to yield probability distributions with moderately high entropy levels. In the present article, we present data charting the performance of the four systems when reasoning in environments of various entropy levels. The results illustrate variations in the performance of the respective reasoning systems that derive from the entropy of the environment, and allow for a more inclusive assessment of the reliability and robustness of the four systems. (shrink)

This paper develops a logical theory that unifies all three standard types of argumentative attack in AI, namely rebutting, undercutting and undermining attacks. We build on default justification logic that already represents undercutting and rebutting attacks, and we add undermining attacks. Intuitively, undermining does not target default inference, as undercutting, or default conclusion, as rebutting, but rather attacks an argument’s premise as a starting point for default reasoning. In default justification logic, reasoning starts from (...) a set of premises, which is then extended by conclusions that hold by default. We argue that modeling undermining defeaters in the view of default theories requires changing the set of premises upon receiving new information. To model changes to premises, we give a dynamic aspect to default justification logic by using the techniques from the logic of belief revision. More specifically, undermining is modeled with belief revision operations that include contracting a set of premises, that is, removing some information from it. The novel combination of default reasoning and belief revision in justification logic enriches both approaches to reasoning under uncertainty. By the end of the paper, we show some important aspects of defeasible argumentation in which our logic compares favorably to structured argumentation frameworks. (shrink)

Rational inference relations were introduced by Lehmann and Magidor as the ideal systems for drawing conclusions from a conditional base. However, there has been no simple characterization of these relations, other than its original representation by preferential models. In this paper, we shall characterize them with a class of total preorders of formulas by improving and extending G ̈ardenfors and Makinson’s results f or expectation inference relations. A second representation is application-oriented and is obtained by considering a class (...) of consequence operators that grade sets of defaults according to our reliance on them. The finitary fragment of this class of consequence operators has been employed by recent default logic formalisms based on maxiconsistency. (shrink)

Three experiments investigating children's understanding of inference as a source of knowledge and beliefs were used to determine whether children use a theory in understanding the mind. A child watched while a sweet was placed in a box whereas a doll was merely given a message about which sweet had been transferred. Children were asked to judge whether the doll knew the colour of the sweet in the box and what colour the do6 would think the sweet was. The (...) main finding was that children tended to say the doll would hold a false belief about the colour of the sweet whenever the doll had not looked in the box. This result is easily reconciled with the theory view as a drive for coherence within the different aspects (knowledge and belier predictions) of the child's theory of mind. The result is contrary to the simulation view because children were generally good at‘inputting’or taking account of the relevant information (i.e. the doll's knowledge of the sweets’colours and the message to the doll), because children assessed their own beliefs quite differently from the doll's beliefs, and because contrary to the default assumptions set out by Harris (1991) children found it easier to assign a false belief to the doll than to assign a true belief. (shrink)

If, as much recent work in the philosophy of action suggests, intention plays a crucial role in the production of intentional action, a complete theory of explanation of intentional action should provide an account of the production of intentions themselves. I shall not offer a perfectly general account in this paper. Rather, I shall limit my investigation to intentions formed or acquired on the basis of practical evaluative inference and to the role of some important kinds of evaluative judgment (...) in the etiology of these intentions. (shrink)

Sometimes agents sincerely profess to believe a claim and yet act inconsistently with it in some contexts. In this paper, I focus on mismatch cases in the domain of religion. I distinguish between two kinds of representations: prompts and default states. Prompts are representations that must be salient to agents in order for them to play their belief-appropriate roles, whereas default states play these roles automatically. The need for access characteristic of prompts is explained by their vehicles: prompts (...) are realized in symbolic systems or even artifacts that make them inapt for automatic regulation of inference and behavior. I argue that some mismatch cases are explained by the fact that agents often report the contents of prompts when they report their beliefs, but behavior is controlled by prompts only when they are made salient to agents. I show that a number of otherwise puzzling findings in the cognitive science of religion, concerning belief intuitiveness, are illuminated by the distinction. (shrink)

This paper trials new experimental methods for the analysis of natural language reasoning and the development of critical ordinary language philosophy in the wake of J.L. Austin. Philosophical arguments and thought experiments are strongly shaped by default pragmatic inferences, including stereotypical inferences. Austin suggested that contextually inappropriate stereotypical inferences are at the root of some philosophical paradoxes and problems, and that these can be resolved by exposing those verbal fallacies. This paper builds on recent efforts to empirically document inappropriate (...) stereotypical inferences that may drive philosophical arguments. We demonstrate that previously employed questionnaire-based output measures do not suffice to exclude relevant confounds. We then report an experiment that combines reading time measurements with plausibility ratings. The study seeks to provide evidence of inappropriate stereotypical inferences from appearance verbs that have been suggested to lie at the root of the influential ‘argument from illusion’. Our findings support a diagnostic reconstruction of this argument. They provide the missing component for proof of concept for an experimental implementation of critical ordinary language philosophy that is in line with the ambitions of current ‘evidential’ experimental philosophy. (shrink)

Grice's distinction between what is said by a sentence and what is implicated by an utterance of it is both extremely familiar and almost universally accepted. However, in recent literature, the precise account he offered of implicature recovery has been questioned and alternative accounts have emerged. In this paper, I examine three such alternative accounts. My main aim is to show that the two most popular accounts in the current literature still face signifi cant problems. I will then conclude by (...) suggesting that an alternative account, emerging from semantic minimalism, is best placed to accommodate Grice's distinction. (shrink)

This book explores important topics in Darwin’s theory of evolution and in the twentieth- and twenty-first-century theories that grew out of it. These topics include fitness, adaptation, altruism, intragenomic conflict, units of selection, genetic drift, the randomness of mutation, gradualism, common ancestry, taxonomy, race, phylogenetic inference, and optimality models. The book brings these and other biological topics into contact with numerous philosophical ideas − operationalism, reductionism, conventionalism, null hypotheses and default reasoning, instrumentalism versus realism, likelihoods versus probabilities, model (...) selection, essentialism, falsifiability, parsimony, the principle of the common cause, comparisons of causal power, interpretations of probaiblity, indeterminism, sensitivity to initial conditions, and the knowability of the past. (shrink)

It is quite plausible to say that you may read or write implies that you may read and you may write (though possibly not both at once). This so-called free choice principle is well-known in deontic logic. Sadly, despite being so intuitive and seemingly innocent, this principle causes a lot of worries. The paper briefly but critically examines leading accounts of free choice permission present in the literature. Subsequently, the paper suggests to accept the free choice principle, but only as (...) a default (or defeasible) rule, issuing to it a ticket-of-leave, granting it some freedom, until it commits an undesired inference. (shrink)

This article presents results from a simulation‐based study of inheritance inference, that is, inference from the typicality of a property among a “base” class to its typicality among a subclass of the class. The study aims to ascertain which kinds of inheritance inferences are reliable, with attention to the dependence of their reliability upon the type of environment in which inferences are made. For example, the study addresses whether inheritance inference is reliable in the case of “exceptional (...) subclasses” (i.e., subclasses that are known to be atypical in some respect) and attends to variations in reliability that result from variations in the entropy level of the environment. A further goal of the study is to show that the reliability of inheritance inference depends crucially on which sorts of base classes are used in making inferences. One approach to inheritance inference treats the extension of any atomic predicate as a suitable base class. A second approach identifies suitable base classes with the cells of a partition (of a preselected size k) of the domain of objects that satisfies the condition of maximizing the similarity of objects that are assigned to the same class. In addition to permitting more inferences, our study shows that the second approach results in inheritance inferences that are far more reliable, particularly in the case of exceptional subclasses. (shrink)

. This paper first provides a brief survey of a possibilistic handling of default rules. A set of default rules of the form, “generally, from α deduce β”, is viewed as the family of possibility distributions satisfying constraints expressing that the situation where α and β is true has a greater plausibility than the one where a and - β is true. When considering only the subset of linear possibility distributions, the well-known System P of postulates proposed by (...) Kraus, Lehmann and Magidor, has been obtained. We also present two rational extensions: one based on the minimum specificity principle and the other is based on the lexicographic ordering. The second part of the paper presents an empirical study of three desirable properties for a consequence relation that capture default reasoning: Rationality, Property Inheritance and Ambiguity Preservation. An experiment is conducted to investigate 13 patterns of inference for the test of these properties. Our experimental apparatus confirms previous results on the relevance of System P, and enforces the psychological relevance of the studied properties. (shrink)

This paper first provides a brief survey of a possibilistic handling of default rules. A set of default rules of the form, "generally, from α deduce β", is viewed as the family of possibility distributions satisfying constraints expressing that the situation where α and β is true has a greater plausibility than the one where α and ⇁β is true. When considering only the subset of linear possibility distributions, the well-known System P of postulates proposed by Kraus, Lehmann (...) and Magidor, has been obtained. We also present two rational extensions: one based on the minimum specificity principle and the other is based on the lexicographic ordering. The second part of the paper presents an empirical study of three desirable properties for a consequence relation that capture default reasoning: Rationality, Property Inheritance and Ambiguity Preservation. An experiment is conducted to investigate 13 patterns of inference for the test of these properties. Our experimental apparatus confirms previous results on the relevance of System P, and enforces the psychological relevance of the studied properties. (shrink)

The field of psychology, including cognitive science, is vexed by a crisis of confidence. Although the causes and solutions are varied, we focus here on a common logical problem in inference. The default mode of inference is significance testing, which has a free lunch property where researchers need not make detailed assumptions about the alternative to test the null hypothesis. We present the argument that there is no free lunch; that is, valid testing requires that researchers test (...) the null against a well-specified alternative. We show how this requirement follows from the basic tenets of conventional and Bayesian probability. Moreover, we show in both the conventional and Bayesian framework that not specifying the alternative may lead to rejections of the null hypothesis with scant evidence. We review both frequentist and Bayesian approaches to specifying alternatives, and we show how such specifications improve inference. The field of cognitive science will benefit because consideration of reasonable alternatives will undoubtedly sharpen the intellectual underpinnings of research. (shrink)

In this article, we outline a simple and intuitively appealing procedure to derive default priors. The main idea is to regard the choice of such a prior as a formal Bayesian decision problem. We also discuss Jeffreys prior and more generally the reference prior of Bernardo (J R Stat Soc B 41:113–147, 1979) from this standpoint.

In this essay we collect and put together a number of ideas relevant to the under- standing of the phenomenon of creativity, confining our considerations mostly to the domain of cognitive psychology while we will, on a few occasions, hint at neuropsy- chological underpinnings as well. In this, we will mostly focus on creativity in science, since creativity in other domains of human endeavor have common links with scientific creativity while differing in numerous other specific respects. We begin by briefly (...) introducing a few basic notions relating to cognition, among which the notion of ‘concepts’ is of basic relevance. The myriads of concepts lodged in our mind constitute a ‘conceptual space’ of an enormously complex structure, where con- cepts are correlated by beliefs that are themselves made up of concepts and are as- sociated with emotions. The conceptual space, moreover, is perpetually in a state of dynamic evolution that is once again of a complex nature. A major component of the dynamic evolution is made up of incessant acts of inference, where an inference occurs essentially by means of a succession of correlations among concepts set up with beliefs and heuristics, the latter being beliefs of a special kind, namely, ones relatively free of emotional associations and possessed of a relatively greater degree of justification. Beliefs, along with heuristics, have been described as the ‘mind’s software’, and con- stitute important cognitive components of the self-linked psychological resources of an individual. The self is the psychological engine driving all our mental and physical activity, and is in a state of ceaseless dynamics resulting from one’s most intimate ex- periences of the world accumulating in the course of one’s journey through life. Many of our psychological resources are of a dual character, having both a self-linked and a shared character, the latter being held in common with larger groups of people and imbibed from cultural inputs. We focus on the privately held self-linked beliefs of an individual, since these are presumably of central relevance in making possible inductive inferences – ones in which there arises a fundamental need of adopting a choice or making a decision. Beliefs, decisions, and inferences, all have the common link to the self of an individual and, in this, are fundamentally analogous to free will, where all of these have an aspect of non-determinism inherent in them. Creativity involves a major restructuring of the conceptual space where a sustained inferential process eventually links remote conceptual domains, thereby opening up the possibility of a large number of new correlations between remote concepts by a cascading process. Since the process of inductive inference depends crucially on de- cisions at critical junctures of the inferential chain, it becomes necessary to examine the basic mechanism underlying the making of decisions. In the framework that we attempt to build up for the understanding of scientific creativity, this role of decision making in the inferential process assumes central relevance. With this background in place, we briefly sketch the affect theory of decisions. Affect is an innate system of response to perceptual inputs received either from the exter- nal world or from the internal physiological and psychological environment whereby a positive or negative valence gets associated with a perceptual input. Almost every sit- uation faced by an individual, even one experienced tacitly, i.e., without overt aware-ness, elicits an affective response from him, carrying a positive or negative valence that underlies all sorts of decision making, including ones carried out unconsciously in inferential processes. Referring to the process of inferential exploration of the conceptual space that gener- ates the possibility of correlations being established between remote conceptual do- mains, such exploration is guided and steered at every stage by the affect system, analogous to the way a complex computer program proceeds through junctures where the program ascertains whether specified conditions are met with by way of generating appropriate numerical values – for instance, the program takes different routes, depending on whether some particular numerical value turns out to be positive or negative. The valence generated by the affect system in the process of adoption of a choice plays a similar role which therefore is of crucial relevance in inferential processes, especially in the exploration of the conceptual space where remote domains need to be linked up – the affect system produces a response along a single value dimension, resembling a number with a sign and a magnitude. While the affect system plays a guiding role in the exploration of the conceptual space, the process of exploration itself consists of the establishment of correlations between concepts by means of beliefs and heuristics, the self-linked ones among the latter having a special role in making possible the inferential journey along alternative routes whenever the shared rules of inference become inadequate. A successful access to a remote conceptual domain, necessary for the creative solution of a standing problem or anomaly – one that could not be solved within the limited domain hitherto accessed – requires a phase of relatively slow cumulative search and then, at some stage, a rapid cascading process when a solution is in sight. Representing the conceptual space in the form of a complex network, the overall process can be likened to one of self-organized criticality commonly observed in the dynamical evolution of complex systems. In order that inferential access to remote domains may actually be possible, it is necessary that restrictions on the exploration process – necessary for setting the context in ordinary instances of inductive inference – be relaxed and a relatively free exploration in a larger conceptual terrain be made possible. This is achieved by the mind going into the default mode, where external constraints – ones imposed by shared beliefs and modes of exploration – are made inoperative. While explaining all these various aspects of the creative process, we underline the supremely important role that analogy plays in it. Broadly speaking, analogy is in the nature of a heuristic, establishing correlations between concepts. However, analo- gies are very special in that these are particularly effective in establishing correlations among remote concepts, since analogy works without regard to the contiguity of the concepts in the conceptual space. In establishing links between concepts, analogies have the power to light up entire terrains in the conceptual space when a rapid cas- cading of fresh correlations becomes possible. The creative process occurs within the mind of a single individual or of a few closely collaborating individuals, but is then continued by an entire epistemic community, eventually resulting in a conceptual revolution. Such conceptual revolutions make pos- sible the radical revision of scientific theories whereby the scope of an extant theory is broadened and a new theoretical framework makes its appearance. The emerging theory is characterized by a certain degree of incommensurability when compared with the earlier one – a feature that may appear strange at first sight. But incommen- surability does not mean incompatibility and the apparently contrary features of the relation between the successive theories may be traced to the multi-layered structureof the conceptual space where concepts are correlated not by means of single links but by multiple ones, thereby generating multiple layers of correlation, among which some are retained and some created afresh in a conceptual restructuring. We conclude with the observation that creativity occurs on all scales. Analogous to correlations being set up across domains in the conceptual space and new domains being generated, processes with similar features can occur within the confines of a domain where a new layer of inferential links may be generated, connecting up sub- domains. In this context, insight can be looked upon as an instance of creativity within the confines of a domain of a relatively limited extent. (shrink)

There has long been a history of studies investigating how people (“ordinary people”) perform on tasks that involve deductive reasoning. The upshot of these studies is that people characteristically perform some deductive tasks well but others badly. For instance, studies show that people will typically perform MP (“modus ponens”: from ‘If A then B’ and ‘A’, infer ‘B’) and bi-conditional MP (from: ‘A if and only if B’ and ‘A’, infer ‘B’) correctly when invited to make the inference and (...) additionally can discover of their own accord when such inferences are appropriate. On the other hand, the same studies show that people typically perform MT (“modus tollens”: from ‘If A then B’ and ‘not-B’, infer ‘not-A’) and biconditional MT badly. They not only do not recognize when it is appropriate to draw such inferences, but also they will balk at doing them even when they are told that they can make it. Related to these shortcomings seems to be the inability of people to understand that contrapositives are equivalent (that ‘If A then B’ is equivalent to ‘If not-B then not-A’). [Studies of people’s deductive inference-drawing abilities have a long history, involving many studies in the early 20th century concerning Aristotelian syllogisms. But the current spate of studies draws much of its impetus from Wason (Wason, 1968; see also Wason & Johnson-Laird, 1972). ] The general conclusion seems to be that there are specific areas where “ordinary people” do not perform very logically. This conclusion will not come as a surprise to teachers of elementary logic, who have long thought that the majority of “ordinary people” are inherently illogical and need deep and forceful schooling in order to overcome this flaw. (shrink)

This paper is a voice in the ongoing discussion on the source and properties of pragmatic inference that contributes to the representation of discourse meaning. I start off from the contextualist standpoint of truth-conditional pragmatics and develop a proposal of representations of utterance meaning, the so-called merger representations, that incorporate the output of pragmatic inference. The move from TCP to pragmatics-rich semantics of acts of communication is facilitated by rethinking the compositionality of meaning and predicating compositionality of such (...) pragmatics-rich structures. I argue that the advantage of 'semanticizing' the output of pragmatic sources of meaning is that we can relax the view on compositionality of meaning and offer an algorithm of the interaction of such sources where the requirement of compositionality is imposed on the output of the interaction rather than on the output of the syntactic processing of the sentence. This proposal is applied to belief reports for which it offers representations of their various readings. (shrink)

A putative problem for the moral particularist is that he or she fails to capture the normative relevance of certain considerations that they carry on their face, or the intuitive irrelevance of other considerations. It is argued in response that mastery of certain topic-specific truisms about a subject matter is what it is for a reasonable interlocutor to be engaged in a moral discussion, but the relevance of these truisms has nothing to do with the particularist/generalist dispute. Given that practical (...) reasoning is plausibly a form of abductive reasoning, and is therefore non-monotonic, any arbitrary addition of information can change the degree of support evidence offers for a conclusion. Given this arbitrariness, it is no objection to the particularist if he or she represents the ‘normative landscape as flat’ in a way that does not display the ‘obvious’ relevance of certain considerations. The normative landscape is flat and our best account of practical reasoning represents it precisely as such. Appealing to a distinction between practical reasoning and moral reasoning does not help to resurrect this pseudoproblem for particularism. Key Words: abductive inference • default reasons • moral particularism • practical reasoning. (shrink)

This is a survey paper. Contents: 1 Introduction -- 2 The representation of belief -- 3 Kinds of belief change -- 4 Coherence constraints for belief revision -- 5 Different modes of belief change -- 6 Two strategies for characterizing rational changes of belief - 6.1 The postulates strategy - 6.2 The constructive strategy -- 7 An abstract view of the elements of belief change -- 8 Iterated changes of belief -- 9 Further developments - 9.1 Variants and extensions of (...) belief revision - 9.2 Updates - 9.3 Default inferences as expectation revision - 9.4 Belief merging -- 10 Concluding remarks. (shrink)

Empirical insights into language processing have a philosophical relevance that extends well beyond philosophical questions about language. This chapter will discuss this wider relevance: We will consider how experimental philosophers can examine language processing in order to address questions in several different areas of philosophy. To do so, we will present the emerging research program of experimental argument analysis (EAA) that examines how automatic language processing shapes verbal reasoning – including philosophical arguments. The evidential strand of experimental philosophy uses mainly (...) questionnaire-based methods to assess the evidentiary value of intuitive judgments that are adduced as evidence for philosophical theories and as premises for philosophical arguments. Extending this prominent strand of experimental philosophy, EAA underpins such assessments, extends the scope of the assessments, and expands the range of the empirical methods employed: EAA examines how automatic inferences that are continually made in language comprehension and production shape verbal reasoning, and draws on findings about comprehension biases that affect the contextualisation of such default inferences, in order to explain and expose fallacies. It deploys findings to assess premises and inferences from premises to conclusions, in philosophical arguments. To do so, it adapts methods from psycholinguistics and recruits methods from computational linguistics. (shrink)

The cognitive science of religion (CSR) was born from dissatisfaction with traditional interpretative accounts of religious symbolism and with the doctrine of the primacy of texts. The theories, methods, and findings of the cognitive sciences provide means for escaping the interpretative circling the former entails and for addressing the myriad nontextual religious phenomena for which the latter is ill‐suited. Whatever else each affirms, all of the pioneering theorists in CSR agree that religions involve cultural arrangements that engage ordinary cognitive systems, (...) which are in place on the basis of considerations having nothing to do with religion or with one another, and are exercised in religious contexts as a byproduct of their normal functioning. Religions engage evolved, domain‐specific cognitive systems for handling problems fundamental to human survival that operate readily, unreflectively, and mostly below the level of consciousness. This information‐processing includes automatically and effortlessly pursuing any of a vast complement of default inferences appropriate to materials from the many domains in question. Such unconscious inferences about intuitive ontology figure centrally in religious representations, which typically involve but a single violation of the concomitant assumptions, rendering those representations minimally counterintuitive (MCI). MCI representations approximate a cognitive optimum, since they are attention‐grabbing, memorable, and inferentially rich. Subsequent theorists have variously argued on the basis of either natural or cultural selection at either the genetic, individual, or group level that some aspects of religious cognition are adaptive, if not outright adaptations. Their principal candidates for adaptive cognitive dispositions and cultural arrangements are ones that enable cooperation in large groups. Cultural group selectionists maintain that, in addition to the content biases that the byproduct view stresses, religions also exploit context biases resulting in characteristic features of honest signals and credibility‐enhancing displays (CREDs), which, in turn, foster cooperation and commitment to (only some) superhuman agents. Big Gods appear to be especially well suited to enhancing cooperation in big groups. CSR has inspired considerable noteworthy experimental research, which, over the past 15 years, has increasingly reflected the three principal influences in cognitive science generally during that time, viz., evolutionary considerations, an interest in experience, and the new brain‐imaging technologies. (shrink)

This article proposes an explanation of the way information about time is conveyed in Navajo.1 We assume that all sentences have a temporal interpretation, direct or indirect. We have two main purposes in this article. The first is to discuss temporal interpretation in this Athabaskan language. The Navajo temporal system, which is varied, has not yet been described in detail. Further, the language allows sentences without explicit temporal information. In such sentences temporal interpretation is indirect - arrived at by (...) class='Hi'>inference. We outline the principles underlying the default inferences. Our second purpose is to show that a few general principles of temporal interpretation, which hold for some other languages, apply very nicely to Navajo. The principles include semantic rules for 1 interpreting explicit expressions about time, and pragmatic principles for inferring temporal location indirectly. The applicability of these principles to Navajo is a satisfying though unsurprising result; but it is worth working out explicitly. The temporal system of Navajo offers a future verb inflection, temporal particles, and temporal adverbs. Although a well-formed sentence need not have any of these forms, speakers consistently agree on temporal interpretation. To account for these facts, we must consider sentences with and without direct temporal information. In this article we propose semantic and pragmatic principles that account for both types of cases. The temporal interpretation of all sentences is deictically based. For sentences without direct temporal forms, aspectual information allows the inference of temporal location. We propose three general pragmatic principles to account for this, which we call temporal interpretation: the Deictic Principle, the Bounded Event Constraint, and a Simplicity Principle. The key factor in temporal inference is boundedness, direct or inferred. To arrive at the inference of boundedness we use the Temporal Schema Principle, a special case of the simplicity principle.. (shrink)

’s glue logic for computing logical form dynamic. This allows us to model a dialogue agent’s understanding of what the update of the semantic representation of the dialogue would be after his next contribution, including the effects of the rhetorical moves that he is contemplating performing next. This is a pre-requisite for developing a model of how agents reason about what to say next. We make the glue logic dynamic by using a dynamic public announcement logic ( pal ). We (...) extend pal with a particular variety of default reasoning suited to reasoning about discourse—this default reasoning being an essential component of inferring the pragmatic effects of one’s dialogue moves. We add to the pal language a new type of announcement, known as ceteris paribus announcement, and this is used to model how an agent anticipates the (default) pragmatic effects of his next dialogue move. Our extended pal validates certain intuitive patterns of default inference that existing pal s for practical reasoning do not. We prove that the dynamic glue logic has a pspace validity problem, and as such is no more complex than pal with multiple $${\square}$$ operators. (shrink)

Several important philosophical problems (including the problems of perception, free will, and scepticism) arise from antinomies that are developed through philosophical paradoxes. The critical strand of ordinary language philosophy (OLP), as practiced by J.L. Austin, provides an approach to such ‘antinomic problems’ that proceeds from an examination of ‘ordinary language’ (how people ordinarily talk about the phenomenon of interest) and ‘common sense’ (what they commonly think about it), and deploys findings to show that the problems at issue are artefacts of (...) fallacious reasoning. The approach is capable, and in need of, empirical development. Proceeding from a case-study on Austin’s paradigmatic treatment of the problem of perception, this paper identifies the key empirical assumptions informing the approach, assesses them in the light of empirical findings about default inferences, contextualisation failures, and belief fragmentation, and explores how these findings can be deployed to address the problem of perception. This facilitates a novel resolution of the problem of perception. Proceeding from this paradigm, the paper proposes ‘experimental critical OLP’ as a new research program in experimental philosophy that avoids apparent non-sequiturs of OLP, extends and transforms experimental philosophy’s ‘sources program’, and provides a promising new strategy for deploying empirical findings about how people ordinarily talk and think about phenomena, to address longstanding philosophical problems. (shrink)

There is no immediate knowledge, neither empirical nor conceptual. Hegel shows this in his Phenomenology of Spirit. He develops this most important insight in his writings on logic. Science is the project of developing situation-independent generic sentences – which are not to be confused with universally quantified empirical statements. Rather, the sentences articulate law sor rules of default inference and proper judgment in a generic way. They are set as “conceptually valid” not only on merely verbal or conventional (...) grounds, but are “material” in their world-relation. In other words, science develops “the concept” which, in turn, enables us to understand, i.e. to use languages and to think about reality and possibilities more or less correctly. “The concept” is, therefore, the system of generic conditions of all “meaning” and “truth” and is, as such, presupposed in empirical judgments of the category of singularity. “Reason” is the subjective side of “spirit”, which, in turn, is nothing but our practice of scientific development. If we look at this practice from within, spirit is the “self-development” of conceptual contents. Moreover, any causal explanation and any appeal to forces or dispositions rest on conceptual constructions of generic models. This is the core claim of Hegel’s idealism with respect to causes and grounds by which we “explain” appearances: The underlying “Wirklichkeit” is our own scientific construction suited to our joint experiences. (shrink)