The aim of this paper is twofold: (i) to introduce the framework of update semantics and to explain what kind of semantic phenomena may successfully be analysed in it: (ii) to give a detailed analysis of one such phenomenon: default reasoning.

Relationship between default semantics and modularity of mind (in particular mind reading through the principle of Relevance).

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)

Reasoning by default is a relevant aspect of everyday life that has traditionally attracted the attention of many fields of research, from psychology to the philosophy of logic, from economics to artificial intelligence. Also in the field of law, default reasoning is widely used by lawyers, judges and other legal decision-makers. In this paper, a philosopher of language (Carlo Penco) and a philosopher of law (Damiano Canale) attempt to explore some uses of default reasoning that are scarcely (...) considered by legal theory. In particular, the dialogue dwells on the notion of literal meaning, witness testimony, and the problem of disagreement among experts in legal proceedings. The paper is intended as a sort of brain storming useful to identify new lines of research straddling philosophy of law, cognitive psychology and philosophy of language. (shrink)

The default theory of aesthetic value combines hedonism about aesthetic value with strict perceptual formalism about aesthetic value, holding the aesthetic value of an object to be the value it has in virtue of the pleasure it gives strictly in virtue of its perceptual properties. A standard theory of aesthetic value is any theory of aesthetic value that takes the default theory as its theoretical point of departure. This paper argues that standard theories fail because they theorize from (...) the default theory. (shrink)

In this paper, I show that Polleit and Mariano (2011) are right in concluding that Credit Default Swaps (CDS) are per se unobjectionable from Rothbard’s libertarian perspective on property rights and contract theory, but that they fail to derive this conclusion properly. I therefore outline the proper explanation. In addition, though Polleit and Mariano are correct in pointing out that speculation with CDS can conceivably hurt the borrowers’ interests, they fail to grasp that this can be the case only (...) in some peculiar circumstances that I identify. In other words, they miss the bigger picture, the one outside special circumstances, in which CDS trading has the opposite effect. That is, CDS facilitate debt accumulation, including government debt accumulation. Finally, I point out how this can precipitate the collapse of fiat money regimes. An incidental goal of the analysis is to provide a better account than Polleit and Mariano of recent government interventions in and around CDS markets. (shrink)

This is a note from an AMC session on Jeff Horty's (2012) book *Reasons as Defaults*.

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)

Findings from two experiments argue in favor of the superiority of default, preferred interpretations over non-default less favored counterparts, outshining degree of non-salience, non-literalness, contextual strength, and negation. They show that, outside of a specific context, the default interpretation of specific negative constructions is a non-salient interpretation 1; their non-default interpretation is a salience-based alternative. In contrast, the default interpretation of the affirmative counterparts is a salience-based interpretation ; their non-default interpretation is a non-salient (...) alternative. When in equally strongly supportive contexts, default yet non-salient negative sarcasm is processed faster than non-default, non-salient yet affirmative sarcasm and faster than non-default yet salience-based negativ.. (shrink)

Default positions, predetermined starting points that aid in complex decision-making, are common in clinical medicine. In this article, we identify and critically examine common default positions in clinical ethics practice. Whether default positions ought to be held is an important normative question, but here we are primarily interested in the descriptive, rather than normative, properties of default positions. We argue that default positions in clinical ethics function to protect and promote important values in medicine—respect for (...) persons, utility, and justice. Further, default positions in clinical ethics may also guard against harm. Where default positions exist, there are epistemic burdens to overturn them. The person wishing to reject the default position, rather than the person endorsing it, bears this burden. The person who bears the burden of meeting the epistemic requirements must provide evidence proportional to the degree of harm the default position protects against. Default positions that protect against significant harm impose significant epistemic requirements to overturn. This asymmetry not only makes medical decision-making more economical but also serves to promote and protect certain values. The identification and analysis of common and recognizable default positions can help to identify other default positions and the conditions under which their associated epistemic requirements are met. The article concludes with considerations of potential problems with the use of default positions in clinical ethics. (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)

Dynamic doxastic logic (DDL) is used in connexion with theories of belief revision. Here we try to show that languages of DDL are suitable also for discussing aspects of default logic. One ingredient of our analysis is a concept of coherence-as-ratifiability.

Inclusion of children in medical decision making, to the extent of their ability and interest in doing so, should be the default position, ensuring that children are routinely given a voice. However, optimizing the involvement of children in their health care decisions remains challenging for clinicians. Missing from the literature is a stepwise approach to assessing when and how a child should be included in medical decision making. We propose a systematic approach for doing so, and we apply this (...) approach in a discussion of two challenging clinical cases. The approach is informed by a literature review, and is anchored by case studies of teenagers' refusal of clinical care, regulatory requirements for research assent, and the accepted approach to involving cognitively impaired adults in medical decisions. (shrink)

Recent literature on causation invokes a distinction between deviant and default behavior to account for token causation. Critical examination of two prominent attempts to employ a distinction between deviants and defaults reveals that the distinction is far from clear. I clarify and develop the distinction by appeal to the notion of a modally robust process, and show how the distinction can be employed by causal process theorists to respond to cases of causation by omission. This shows that the (...) class='Hi'>default/deviant distinction is not so much a tool for counterfactual accounts of causation, but rather for causal process theory. (shrink)

This paper defends a new version of truthmaker non-maximalism. The central feature of the view is the notion of a default truth-value. I offer a novel explanation for default truth-values and use it to motivate a general approach to the relation between truth-value and ontology, which I call truth-value-maker theory. According to this view, some propositions are false unless made true, whereas others are true unless made false. A consequence of the theory is that negative existential truths need (...) no truthmakers and that positive existential falsehoods need no falsemakers. (shrink)

There is a fundamental disconnect between the public discourse about sovereign and external debt in comparison to private domestic debt. The latter is predominantly viewed through a Humean lens, which sees economic morality in terms of contingent social institutions, justified by the valuable goods they realize; while sovereign and external debt is viewed through a Lockean lens, which sees property, contract, and debt as possessing an intrinsic moral quality, independent of social context or consequences. This Article examines whether this Lockean (...) perspective on sovereign and external debt is compatible with the dominance of Humean approaches to the domestic economy. It considers and rejects the most plausible argument for reconciling these views, which emphasizes the different qualities of cooperation in the international and domestic economies. It further argues that many standard objections to a Humean approach to sovereign debt suggest, not the Lockean approach, but rather a Hobbesian international moral skepticism. Concluding that the Lockean approach is unmotivated, this Article instead advances a Humean account of sovereign debt and default. It shows how taking seriously the demand for institutional justification and the idea of persons and peoples as free and equal provides an account of the duties of states—whether creditors, debtors or third parties—in sovereign debt crises. It further examines the implications of each approach for democratic choice about sovereign default. (shrink)

Some theorists have recently raised doubts about much of the experimental evidence purporting to demonstrate the existence of unconscious perception. In our (2019) in this journal, we argued some of these considerations are not decisive. Phillips (forthcoming a) replies thoughtfully to our paper, concluding that he is unconvinced by our arguments. Phillips maintains that the view that perception is invariably conscious remains, as he puts it, the “default” hypothesis both within the folk understanding and experimental study of perception. There (...) is much to agree with in Phillips’ piece, but there remain some substantive points of disagreement, which we outline here. (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)

In the age of big data, machine learning models are globally used to execute default risk prediction. Imbalanced datasets and redundant features are two main problems that can reduce the performance of machine learning models. To address these issues, this study conducts an analysis from the viewpoint of different balance ratios as well as the selection order of feature selection. Accordingly, we first use data rebalancing and feature selection to obtain 32 derived datasets with varying ratios of balance and (...) feature combinations for each dataset. Second, we propose a comprehensive metric model based on multimachine learning algorithms to select the best-derived dataset with the optimal balance ratio and feature combination. Finally, the convolutional neural network is trained on the selected derived dataset to evaluate the performance of our approach in terms of type-II error, accuracy, G-mean, and AUC. There are two contributions in this study. First, the optimal balance ratio is found through the classification accuracy, which changes the deficiency of the existing research that samples are imbalanced or the balance ratio is 1 : 1 and ensures the accuracy of the classification model. Second, a comprehensive metric model based on the machine learning algorithm is proposed, which can simultaneously find the best balance ratio and the optimal feature selection. The experimental results show that our method can noticeably improve the performance of CNN, and CNN outperforms the other four commonly used machine learning models in the task of default risk prediction on four benchmark datasets. (shrink)

It may seem that epistemic and practical rationality weigh reasons differently, because ties in practical rationality tend to generate permissions and ties in epistemic rationality tend to generate a requirement to withhold judgment. I argue that epistemic and practical rationality weigh reasons in the same way, but they have different "default biases". Practical rationality is biased toward every option being permissible whereas epistemic rationality is biased toward withholding judgment's being required.

This paper describes a pair of dietary practices I label default vegetarianism and default veganism. The basic idea is that one adopts a default of adhering to vegetarian and vegan diets, with periodic exceptions. While I do not exhaustively defend either of these dietary practices as morally required, I do suggest that they are more promising than other dietary practices that are normally discussed like strict veganism and vegetarianism. For they may do a better job of striking (...) a balance between normative concerns about contemporary farming practices and competing considerations of life. Additionally, I argue that framing discussions in terms of defaults is useful for various reasons: it helps organize agreements and disagreements, it more accurately reflects the way people conceptualize their dietary practices, and it presents a more dialectically effective view. (shrink)

This paper focuses on a potential problem with Sosa’s theory of default assumption, viz., the alleged incompatibility of this theory with the closure principle. Given the similarity between the notion of default assumption and Wittgenstein’s notion of hinge commitment, I suggest that two influential hinge epistemologies including Wright’s entitlement theory and Pritchard’s non-belief theory provide resources for possible solutions to the problem. I argue that default assumption should be classified as acceptance and hence as a non-doxastic propositional (...) attitude. Sosa’s theory can deal with the apparent incompatibility with the closure principle by adopting the solution of the non-belief theory, while also avoiding problems affecting the latter view. (shrink)

Look before you leap. - Proverb. He who hesitates is lost. - Another proverb.

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 the modifier 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 block default inheritance of 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)

Currently there is hardly any connection between philosophy of science and Artificial Intelligence research. We argue that both fields can benefit from each other. As an example of this mutual benefit we discuss the relation between Inductive-Statistical Reasoning and Default Logic. One of the main topics in AI research is the study of common-sense reasoning with incomplete information. Default logic is especially developed to formalise this type of reasoning. We show that there is a striking resemblance between inductive-statistical (...) reasoning and default logic. A central theme in the logical positivist study of inductive-statistical reasoning such as Hempels Criterion of Maximal Specificity turns out to be equally important in default logic. We also discuss to what extent the relevance of the results of Logical Positivism to AI research could contribute to a reevaluation of Logical Positivism in general. (shrink)

Objective To determine whether presenting delivery room management options as defaults influences decisions to resuscitate extremely premature infants. Materials and methods Adult volunteers recruited from the world wide web were randomised to receive either resuscitation or comfort care as the delivery room management default option for a hypothetical delivery of a 23-week gestation infant. Participants were required to check a box to opt out of the default. The primary outcome measure was the proportion of respondents electing resuscitation. Data (...) were analysed using χ2 tests and multivariate logistic regression. Results Participants who were told the delivery room management default option was resuscitation were more likely to opt for resuscitation (OR 6.54 95% CI 3.85 to 11.11, p<0.001). This effect persisted on multivariate regression analysis (OR 7.00, 95% CI 3.97 to 12.36, p<0.001). Female gender, being married or in a committed relationship, being highly religious, experiences with prematurity, and favouring sanctity of life were significantly associated with decisions to resuscitate. Discussion Presenting delivery room options for extremely premature infants as defaults exert a significant effect on decision makers. The information structure of the choice task may act as a subtle form of manipulation. Further, this effect may operate in ways that a decision maker is not aware of and this raises questions of patient autonomy. Conclusion Presenting delivery room options for extremely premature infants as defaults may compromise autonomous decision-making. (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)

In this paper I will argue that (principled) attempts to ground a priori knowledge in default reasonable beliefs cannot capture certain common intuitions about what is required for a priori knowledge. I will describe hypothetical creatures who derive complex mathematical truths like Fermat’s last theorem via short and intuitively unconvincing arguments. Many philosophers with foundationalist inclinations will feel that these creatures must lack knowledge because they are unable to justify their mathematical assumptions in terms of the kind of basic (...) facts which can be known without further argument. Yet, I will argue that nothing in the current literature lets us draw a principled distinction between what these creatures are doing and paradigmatic cases of good a priori reasoning (assuming that the latter are to be grounded in default reasonable beliefs). I will consider, in turn, appeals to reliability, coherence, conceptual truth and indispensability and argue that none of these can do the job. (shrink)

We reject the concept of a default option of withdrawal as proposed by Syltern and colleagues, and will outline here potential consequences on parental trust, particularly in historically marginali...

Particularism takes an extremely ecumenical view of what considerations might count as reasons and thereby threatens to ‘flatten the moral landscape’ by making it seem that there is no deep difference between, for example, pain, and shoelace color. After all, particularists have claimed, either could provide a reason provided a suitable moral context. To avoid this result, some particularists draw a distinction between default and non-default reasons. The present paper argues that all but the most deflationary ways of (...) drawing this distinction are either implausible or else insufficient to help the particularist avoid flattening the moral landscape. The difficulty can be avoided, however, if we reject particularism's extremely ecumenical view of reasons. (shrink)

We propose a combination of probabilistic reasoning from conditional constraints with approaches to default reasoning from conditional knowledge bases. In detail, we generalize the notions of Pearl's entailment in system Z, Lehmann's lexicographic entailment, and Geffner's conditional entailment to conditional constraints. We give some examples that show that the new notions of z-, lexicographic, and conditional entailment have similar properties like their classical counterparts. Moreover, we show that the new notions of z-, lexicographic, and conditional entailment are proper generalizations (...) of both their classical counterparts and the classical notion of logical entailment for conditional constraints. (shrink)

The goal of this paper is to frame a theory of reasons--what they are, how they support actions or conclusions--using the tools of default logic. After sketching the basic account of reasons as provided by defaults, I show how it can be elaborated to deal with two more complicated issues: first, situations in which the priority relation among defaults, and so reasons as well, is itself established through default reasoning; second, the treatment of undercutting defeat and exclusionary reasons. (...) Finally, and by way of application, I show how the resulting account can shed some light on Jonathan Dancy's argument from reason holism to a form of extreme particularism in moral theory. (shrink)

I discuss two claims defended in Fischer’s recent work. The first is the default status of compatibilism. This is part of a conception of our agency and moral responsibility as being independent of the truth or the falsity of the thesis of determinism. I try to further bolster Fischer’s arguments in favor of this position. The second is Fischer’s defense of the narrative conception of moral responsibility, according to which the value of self-expression supports and explicates the value of (...) being morally responsible. I argue that the cases and insights taken to support the idea that our lives have a distinctive kind of narrative value are best accounted for in other terms. (shrink)

The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of (...) the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D llustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system. (shrink)

The capacity for representing and reasoning over sets of possibilities, or modal cognition, supports diverse kinds of high-level judgments: causal reasoning, moral judgment, language comprehension, and more. Prior research on modal cognition asks how humans explicitly and deliberatively reason about what is possible but has not investigated whether or how people have a default, implicit representation of which events are possible. We present three studies that characterize the role of implicit representations of possibility in cognition. Collectively, these studies differentiate (...) explicit reasoning about possibilities from default implicit representations, demonstrate that human adults often default to treating immoral and irrational events as impossible, and provide a case study of high-level cognitive judgments relying on default implicit representations of possibility rather than explicit deliberation. (shrink)

Although the study of reasons plays an important role in both epistemology and moral philosophy, little attention has been devoted to the question of how, exactly, reasons interact to support the actions or conclusions they do. In this book, John F. Horty attempts to answer this question by providing a precise, concrete account of reasons and their interaction, based on the logic of default reasoning. The book begins with an intuitive, accessible introduction to default logic itself, and then (...) argues that this logic can be adapted to serve as a foundation for a concrete theory of reasons. Horty then shows that the resulting theory helps to explain how the interplay among reasons can determine what we ought to do by developing two different deontic logics, capturing two different intuitions about moral conflicts.In the central part of the book, Horty elaborates the basic theory to account for reasoning about the strength of our own reasons, and also about the related concepts of undercutting defeaters and exclusionary reasons. The theory is illustrated with an application to particularist arguments concerning the role of principles in moral theory. The book concludes by introducing a pair of issues new to the philosophical literature: the problem of determining the epistemic status of conclusions supported by separate but conflicting reasons, and the problem of drawing conclusions from sets of reasons that can vary arbitrarily in strength, or importance. (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 the earliest formalisation of default logic by Reiter many contributions to this appealing approach to nonmonotonic reasoning have been given. The different formalisations are here presented in a general framework that gathers the basic notions, concepts and constructions underlying default logic. Our view is to interpret defaults as special rules that impose a restriction on the juxtaposition of monotonic Hubert-style proofs of a given logicL. We propose to describe default logic as a logic where the juxtaposition (...) of default proofs is subordinate to a restriction condition . Hence a default logic is a pair (L, ) where properties of the logic , like compactness, can be interpreted through the restriction condition . Different default systems are then given a common characterization through a specific condition on the logicL. We also prove cumulativity for any default logic (L, ) by slightly modifying the notion of default proof. We extend, in fact, the language ofL in a way close to that followed by Brewka in the formulation of his cumulative default system. Finally we show the existence of infinitely many intermediary default logics, depending on and called linear logics, which lie between Reiter's and ukaszewicz' versions of default logic. (shrink)

Epistemology of testimony’s map has been charted by identifying the basic controversy between reductionism and non-reductions. John McDowell’s article “Knowledge by Hearsay” (1993/1998) has been taken as a clear example of non-reductionism. This is, however, only partially right. It is correct that, as a non-reductionist, he defends the justifying role that the default position plays in testimonial knowledge. But, his insistence on situating the default position inside the space of reasons suggests that default position should be understood (...) as a kind of reasoning, and that only then evidential reasons can be applied in concrete justifying procedures. This is a very different understanding of the default position from that of classical non-reductionists such as Coady (1992) and Burge (1993, 1997). If McDowell’s epistemology of testimony can be understood in this way, as this paper aims to establish, it should be considered as an attempt tosupersede the reductionist and non-reductionist dichotomy, an attempt that brings a series of reconsiderations of a satisfactory epistemology of testimony. (shrink)

This article considers the principles that ought to be used to determine the scope and content of contract law's «default rules», the rules that will, in the absence of express exclusion, govern parties» contractual relationships. It examines three, ostensibly competing, approaches discussed in the literature: that defaults be grounded in the subjective consent of contracting parties, in the customs and norms immanent within the parties» community, and in the value of economic efficiency. It argues that each has something of (...) value to tell us about default rules, but that none can, in isolation, offer a wholly compelling prescription for their design. Rather, the best such prescription must be an eclectic one, drawing something from all three accounts, but varying to reflect the institution promulgating the default. Where defaults are promulgated legislatively, the case for choosing rules that will promote efficiency is a strong one, and the main criticism of efficiency analysis is shown, in this particular context, to be misguided. Where, however, defaults are promulgated adjudicatively—in the context of settling individual cases—the normative appeal of efficiency is much reduced. The article, then, criticizes efficient adjudicative defaults against their defenders, whilst defending efficient legislative defaults against their critics. (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)