Reductive intellectualists (e.g., Stanley & Williamson 2001; Stanley 2011a; 2011b; Brogaard 2008; 2009; 2011) hold that knowledge-how is a kind of knowledge-that. If this thesis is correct, then we should expect the defeasibility conditions for knowledge-how and knowledge-that to be uniform—viz., that the mechanisms of epistemic defeat which undermine propositional knowledge will be equally capable of imperilling knowledge-how. The goal of this paper is twofold: first, against intellectualism, we will show that knowledge-how is in fact resilient to being undermined (...) by the very kinds of traditional (propositional) epistemic defeaters which clearly defeat the items of propositional knowledge which intellectualists identify with knowledge-how. Second, we aim to fill an important lacuna in the contemporary debate, which is to develop an alternative way in which epistemic defeat for knowledge-how could be modelled within an anti-intellectualist framework. (shrink)

The paper starts by describing and clarifying what Williamson calls the consequence fallacy. I show two ways in which one might commit the fallacy. The first, which is rather trivial, involves overlooking background information; the second way, which is the more philosophically interesting, involves overlooking prior probabilities. In the following section, I describe a powerful form of sceptical argument, which is the main topic of the paper, elaborating on previous work by Huemer. The argument attempts to show the impossibility of (...) defeasible justification, justification based on evidence which does not entail the (allegedly) justified proposition or belief. I then discuss the relation between the consequence fallacy, or some similar enough reasoning, and that form of argument. I argue that one can resist that form of sceptical argument if one gives up the idea that a belief cannot be justified unless it is supported by the totality of the evidence available to the subject—a principle entailed by many prominent epistemological views, most clearly by epistemological evidentialism. The justification, in the relevant cases, should instead derive solely from the prior probability of the proposition. A justification of this sort, that does not rely on evidence, would amount to a form of entitlement, in (something like) Crispin Wright’s sense. I conclude with some discussion of how to understand prior probabilities, and how to develop the notion of entitlement in an externalist epistemological framework. (shrink)

According to the Reasoning View about normative reasons, facts about normative reasons for action can be understood in terms of facts about the norms of practical reasoning. I argue that this view is subject to an overlooked class of counterexamples, familiar from debates about Subjectivist theories of normative reasons. Strikingly, the standard strategy Subjectivists have used to respond to this problem cannot be adapted to the Reasoning View. I think there is a solution to this problem, however. I argue that (...) the norms of practical reasoning, like the norms of theoretical reasoning, are characteristically defeasible, in a sense I make precise. Recognizing this property of those norms makes space for a solution to the problem. The resulting view is in a way analogous to the familiar defeasibility theory of knowledge, but it avoids a standard objection to that theory. (shrink)

We contend that it is possible to argue reasonably for and against arguments from classifications and definitions, provided they are seen as defeasible (subject to exceptions and critical questioning). Arguments from classification of the most common sorts are shown to be based on defeasible reasoning of various kinds represented by patterns of logical reasoning called defeasible argumentation schemes. We show how such schemes can be identified with heuristics, or short-cut solutions to a problem. We examine a variety of arguments of (...) this sort, including argument from abductive classification, argument from causal classification, argument from analogy-based classification and arguments from classification based on generalizations. (shrink)

The applicability of Bayesian conditionalization in setting one’s posterior probability for a proposition, α, is limited to cases where the value of a corresponding prior probability, PPRI(α|∧E), is available, where ∧E represents one’s complete body of evidence. In order to extend probability updating to cases where the prior probabilities needed for Bayesian conditionalization are unavailable, I introduce an inference schema, defeasible conditionalization, which allows one to update one’s personal probability in a proposition by conditioning on a proposition that represents a (...) proper subset of one’s complete body of evidence. While defeasible conditionalization has wider applicability than standard Bayesian conditionalization (since it may be used when the value of a relevant prior probability, PPRI(α|∧E), is unavailable), there are circumstances under which some instances of defeasible conditionalization are unreasonable. To address this difficulty, I outline the conditions under which instances of defeasible conditionalization are defeated. To conclude the article, I suggest that the prescriptions of direct inference and statistical induction can be encoded within the proposed system of probability updating, by the selection of intuitively reasonable prior probabilities. (shrink)

Defeasible argumentation has been applied successfully in several real-world domains in which it is necessary to handle incomplete and contradictory information. In recent years, there have been interesting attempts to carry out argumentation processes supported by massive repositories developing argumentative reasoning applications. One of such efforts builds arguments by retrieving information from relational databases using the DBI-DeLP framework; this article presents eDBI-DeLP, which extends the original DBI-DeLP framework by providing two novel aspects which refine the interaction between DeLP programs and (...) relational databases. First, we expand the expressiveness of dbi-delp programs by providing ways of controlling how the information in databases is recovered; this is done by introducing filters that enable an improved fine-grained control on the argumentation processes which become useful in applications, providing the semantics and the implementation of such filters. Second, we introduce an argument comparison criterion which can be adjusted at the level of literals to model particular features such as credibility and topic expertise, among others. These new tools can be particularly useful in environments such as medical diagnosis expert systems, decision support systems, or recommender systems based on argumentation, where datasets are often provided in the form of relational databases. (shrink)

Discussion of the behaviour of pregnant women and mothers, in academic literature, medical advice given to mothers, mainstream media and social media, assumes that a mother who fails to do something to benefit her child is liable for moral criticism unless she can provide sufficient countervailing considerations to justify her decision. I reconstruct the normally implicit reasoning that leads to this assumption and show that it is mistaken. First, I show that the discussion assumes that if any action might benefit (...) her child, the mother has a defeasible duty to perform that action. I suggest that this assumption is implicitly supported by two arguments but that each argument is unsound. The first argument conflates moral reasons and defeasible duties; the second misunderstands the scope of a defeasible duty to benefit. This argument has important practical and theoretical implications: practically, it provides a response to a highly damaging discourse on maternal behaviour; theoretically, it provides the framework for a clearer understanding of the scope and nature of defeasible duties to benefit. (shrink)

According to the so-called ‘Taking Condition’ (a label due to Boghossian 2014) on inference, for a response R in circumstances C to count as an instance of reasoning or inferring, it must be the case that the agent’s taking it that R is warranted or justified in C plays (the right sort of) explanatory role in her R-ing. The Taking Condition has come under much criticism in the theory of reasoning. While I believe that these criticisms can be answered, my (...) aim in this paper is to build a positive case for the Taking Condition. More specifically, I argue that views based on the Taking Condition do a much better job accounting for crucial features of reasoning—especially once we recognize the pervasiveness and significance of defeasibility in our reasoning. (shrink)

In recent years, the e ffort to formalize erotetic inferences (i.e., inferences to and from questions) has become a central concern for those working in erotetic logic. However, few have sought to formulate a proof theory for these inferences. To fill this lacuna, we construct a calculus for (classes of) sequents that are sound and complete for two species of erotetic inferences studied by Inferential Erotetic Logic (IEL): erotetic evocation and regular erotetic implication. While an attempt has been made to (...) axiomatize the former in a sequent system, there is currently no proof theory for the latter. Moreover, the extant axiomatization of erotetic evocation fails to capture its defeasible character and provides no rules for introducing or eliminating question-forming operators. In contrast, our calculus encodes defeasibility conditions on sequents and provides rules governing the introduction and elimination of erotetic formulas. We demonstrate that an elimination theorem holds for a version of the cut rule that applies to both declarative and erotetic formulas and that the rules for the axiomatic account of question evocation in IEL are admissible in our system. (shrink)

According to informal logic, the possibilities of deductive logic as a tool for analysing and evaluating ordinary arguments are very limited. While I agree with this claim in general, I question it in the case of the argument from cause to effect. In this paper I first show, on the basis of carefully chosen examples, that we usually react differently to falsification of the conclusion of the argument from cause to effect than we do to the falsification of the conclusion (...) of other defeasible arguments. I then identify general conditions and assumptions under which the causal argument from cause to effect can be reconstructed as deductive. Finally, I compare the causal argument with the expert argument, which is a typical example of a defeasible argument in the narrower sense. (shrink)

Two truisms about empirical justification are that experience plays a crucial role in it and that it is defeasible. There are, of course, different ways of developing these truisms into philosophical theories. I favor one particular view about the role of experience in empirical justification which may be thought to lead to problems in accommodating its defeasibility. My aim in this paper is to argue that the problems are illusory, based on an entrenched misconception how defeaters work.

The purpose of this paper is to analyze the structure and the defeasibility conditions of argument from analogy, addressing the issues of determining the nature of the comparison underlying the analogy and the types of inferences justifying the conclusion. In the dialectical tradition, different forms of similarity were distinguished and related to the possible inferences that can be drawn from them. The kinds of similarity can be divided into four categories, depending on whether they represent fundamental semantic features of (...) the terms of the comparison or non-semantic ones, indicating possible characteristics of the referents. Such distinct types of similarity characterize different kinds of analogical arguments, all based on a similar general structure, in which a common genus is abstracted. Depending on the nature of the abstracted common feature, different rules of inference will apply, guaranteeing the attribution of the analogical predicate to the genus and to the primary subject. This analysis of similarity and the relationship thereof with the rules of inference allows a deeper investigation of the defeasibility conditions. (shrink)

Thinking about misleading higher-order evidence naturally leads to a puzzle about epistemic rationality: If one’s total evidence can be radically misleading regarding itself, then two widely-accepted requirements of rationality come into conflict, suggesting that there are rational dilemmas. This paper focuses on an often misunderstood and underexplored response to this (and similar) puzzles, the so-called conflicting-ideals view. Drawing on work from defeasible logic, I propose understanding this view as a move away from the default metaepistemological position according to which rationality (...) requirements are strict and governed by a strong, but never explicitly stated logic, toward the more unconventional view, according to which requirements are defeasible and governed by a comparatively weak logic. When understood this way, the response is not committed to dilemmas. (shrink)

One can intentionally do something only if one knows what one is doing while they are doing it. For example, one can intentionally kill one’s neighbor by opening their gas stove overnight only if one knows that the gas is likely to kill the neighbor in their sleep. One can intentionally sabotage the victory of one’s rival by putting sleeping drugs in their drink only if one knows that sleeping drugs will harm the rival’s performance. And so on. In a (...) slogan: Intentional action is action guided by knowledge. This essay reviews some motivations for a ‘knowledge-centered psychology’ — a psychology where knowledge enters center stage in an explanation of intentional action (§2). Then it outlines a novel argument for the claim that knowledge is required for intentional action (§3) and discusses some of its consequences (§§4-5). (shrink)

I objected that the defeasibility theory of knowledge prohibits you from knowing that you know that p if your knowledge that p is a posteriori. Rodrigo Borges claims that Peter Klein has already satisfactorily answered a version of my objection. He attempts to defend Klein’s reply and argues that my objection fails because a principle on which it is based is false.I will show that my objection is not a version of the old one that Klein attempts (unsuccessfully) to (...) address, that Borges’ defence of Klein’s reply fails and that his argument against my new objection leaves it untouched. (shrink)

For many women experiencing motherhood for the first time, the message they receive is clear: mothers who do not breastfeed ought to have good reasons not to; bottle feeding by choice is a failure of maternal duty. We argue that this pressure to breastfeed arises in part from two misconceptions about maternal duty: confusion about the scope of the duty to benefit and conflation between moral reasons and duties. While mothers have a general duty to benefit, we argue that this (...) does not imply a duty to carry out any particular beneficent act. Therefore, the expectation that mothers should breastfeed unless they have sufficient countervailing reasons not to is morally unwarranted. Recognising the difference between reasons and duties can allow us to discuss the benefits of breastfeeding and the importance of supporting mothers who wish to breastfeed without subjecting mothers who bottle feed to guilt, blame and failure. (shrink)

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)

I will discuss a variety of cases such that the subject's believing truly is somewhat of an accident, but less so than in a Gettier case. In each case, this is because her reasons are not ultimately undefeated full stop, but they are ultimately undefeated with certain qualifications. For example, the subject's reasons might be ultimately defeated considered in themselves but ultimately undefeated considered as a proper part of an inference to the best explanation that is undefeated without qualification. In (...) each section of the paper, I consider different qualifications and show how in each case we get an epistemic standing I call “coach-class knowledge”. First-class knowledge requires justifying reasons that are undefeated without qualification. Coach-class knowledge only requires qualified lack of defeat. I will use this distinction to bring debates over knowledge from falsehood and fake barns to an ecumenical resolution. In both cases, the subject enjoys coach-class rather than first-class knowledge. I will also show that the defeasible reasoning tradition can better account for graded accidental truth than safety theories. (shrink)

In some recent work, John N.Williams defends a new objection to the defeasibility theory of knowledge. But the objection is of wider interest, since Williams also suggests that this style of objection may undermine other theories of knowledge. I distinguish two versions of Williams’ objection. I then show that the first version relies on false conceptual principles, and the second relies on a specific and dubious conception of the goal of the analysis of knowledge.

In this article, we redefine classical notions of theory reduction in such a way that model-theoretic preferential semantics becomes part of a realist depiction of this aspect of science. We offer a model-theoretic reconstruction of science in which theory succession or reduction is often better - or at a finer level of analysis - interpreted as the result of model succession or reduction. This analysis leads to 'defeasible reduction', defined as follows: The conjunction of the assumptions of a reducing theory (...) T with the definitions translating the vocabulary of a reduced theory T' to the vocabulary of T, defeasibly entails the assumptions of reduced T'. This relation of defeasible reduction offers, in the context of additional knowledge becoming available, articulation of a more flexible kind of reduction in theory development than in the classical case. Also, defeasible reduction is shown to solve the problems of entailment that classical homogeneous reduction encounters. Reduction in the defeasible sense is a practical device for studying the processes of science, since it is about highlighting different aspects of the same theory at different times of application, rather than about naive dreams concerning a metaphysical unity of science. (shrink)

When there are two lines of argument that contradict each other but still end up with the same conclusion, this conclusion is called a floating conclusion. It is an open topic in skeptical defeasible reasoning if floating conclusions ought to be accepted. Inter- estingly, the answer seems to be changing for different examples. In this paper, we propose a solution for explaining the different treatments of the floating conclusion in the various examples from the literature. We collect the examples from (...) the literature, extend them with additional examples and test various hypotheses for explaining the difference by means of the examples. We will argue for a framework that accepts a floating conclusion by default but allows for reasons to deviate from the default in order to reject it. These reasons nicely explain the different underlying patterns of our intuitions. (shrink)

A number of Christian theologians and philosophers have been critical of overly moralizing approaches to the doctrine of sin, but nearly all Christian thinkers maintain that moral fault is necessary or sufficient for sin to obtain. Call this the “Moral Consensus.” I begin by clarifying the relevance of impurities to the biblical cataloguing of sins. I then present four extensional problems for the Moral Consensus on sin, based on the biblical catalogue of sins: (1) moral over-demandingness, (2) agential unfairness, (3) (...) moral repugnance, and (4) moral atrocity. Next, I survey several partial solutions to these problems, suggested by the recent philosophical literature. Then I evaluate two largely unexplored solutions: (a) genuine sin dilemmas and (b) defeasible sinfulness. I argue that (a) creates more problems than it solves and that, while (b) is well-motivated and solves or eases each of the above problems, (b) leaves many biblical ordinances about sin morally misleading, creating (5) a pedagogical problem of evil. I conclude by arguing that (5) places hefty explanatory burdens on those who would appeal to (b) to resolve the four extensional problems discussed in this paper. So Christian thinkers may need to consider a more radical separation of sin and moral fault. (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)

According to conciliatory views on the significance of disagreement, it’s rational for you to become less confident in your take on an issue in case your epistemic peer’s take on it is different. These views are intuitively appealing, but they also face a powerful objection: in scenarios that involve disagreements over their own correctness, conciliatory views appear to self-defeat and, thereby, issue inconsistent recommendations. This paper provides a response to this objection. Drawing on the work from defeasible logics paradigm and (...) abstract argumentation, it develops a formal model of conciliatory reasoning and explores its behavior in the troubling scenarios. The model suggests that the recommendations that conciliatory views issue in such scenarios are perfectly reasonable—even if outwardly they may look odd. (shrink)

In a 2002 article Stewart Cohen advances the “bootstrapping problem” for what he calls “basic justification theories,” and in a 2010 followup he offers a solution to the problem, exploiting the idea that suppositional reasoning may be used with defeasible as well as with deductive inference rules. To curtail the form of bootstrapping permitted by basic justification theories, Cohen insists that subjects must know their perceptual faculties are reliable before perception can give them knowledge. But how is such knowledge of (...) reliability to be acquired if not through perception itself? Cohen proposes that such knowledge may be acquired a priori through suppositional reasoning. I argue that his strategy runs afoul of a plausible view about how epistemic principles function; in brief, I argue that one must actually satisfy the antecedent of an epistemic principle, not merely suppose that one does, to acquire any justification by its means – even justification for a merely conditional proposition. (shrink)

The concept of epistemic defeat or defeasibility has come to occupy an important place in contemporary epistemology, especially in relation to the closely allied concepts of justified belief, warrant, and knowledge. These allied concepts signify positive epistemic appraisal or positive epistemic status. As a first approximation, defeasibility refers to a belief’s liability to lose some positive epistemic status, or to having this status downgraded in some particular way. For example, a person may be epistemically justified in believing some (...) proposition p at one time, but then the belief might become less justified or even unjustified at some later time. Moreover, beliefs may also be prevented from having or acquiring some positive epistemic status in the first place. So more generally, defeasibility refers to a kind of epistemic liability or vulnerability, the potential of loss, reduction, or prevention of some positive epistemic status. A defeater is, broadly speaking, a condition that actualizes this potential. This article begins by outlining two general types of defeaters: propositional defeaters and mental state defeaters. Propositional defeaters are conditions external to the perspective of the cognizer that prevent an overall justified true belief from counting as knowledge. Mental state defeaters are conditions internal to the perspective of the cognizer (such as experiences, beliefs, withholdings) that cancel, reduce, or even prevent justification. (shrink)

Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsistent information. When strong negation is also allowed, contradictory conclusions can arise. A criterion for deciding between them is needed. The aim of this paper is to investigate an inherent and autonomous comparison criterion, based on specificity as defined in [POO 85, SIM 92]. In contrast to other approaches, we consider not only defeasible, but also strict knowledge. Our criterion is context-sensitive, i. e., preference among defeasible rules is determined dynamically (...) during the dialectical analysis.We show how specificity can be defined in terms of two different approaches: activation sets and derivation trees. This allows us to get a syntactic criterion that can be implemented in a computationally attractive way. The resulting definitions may be applied in general rulebased formalisms. We present theorems linking both characterizations. Finally we discuss other frameworks for defeasible reasoning in which preference handling is considered explicitly. (shrink)

Here I will develop a naturalistic account of epistemic reflection and its significance for epistemology. I will first argue that thought, as opposed to mere information processing, requires a capacity for cognitive self-regulation. After discussing the basic capacities necessary for cognitive self-regulation of any kind, I will consider qualitatively different kinds of thought that can emerge when the basic capacities enable the creature to interiorize a form of social cooperation. First, I will discuss second-personal cooperation and the kind of thought (...) that emerges from its interiorization. Then, I will discuss third-personal cooperation and the kind of thought that emerges from its interiorization. We will see that epistemic reflection is the interiorized version of interpersonal argumentation, which is the epistemic component of third-personal cooperation. In developing this account, I will draw heavily on the work of Michael Tomasello and other cognitive scientists advocating the “social intentionality hypothesis”. However, I will show how work done in the defeasible reasoning tradition can provide us with a deeper explanation of some claims made by advocates of the social intentionality hypothesis. Additionally, we will see that work done on social intentionality can help us better understand the significance of knowledge and justification as understood by the defeasible reasoning tradition. We will see that the social intentionality hypothesis and the defeasible reasoning tradition are mutually illuminating. By drawing equally on both, I will provide a novel account of the foundations of knowledge. (shrink)

Dual-role approaches to reasons say, roughly, that reasons can relate to actions in two fundamentally different ways: they can either require conformity, or justify an action without requiring that it be taken. This paper develops a formal dual-role approach, combining ideas from defeasible logic and practical philosophy. It then uses the approach to shed light on the phenomenon of supererogation and resolve a well-known puzzle about supererogation, namely, Horton’s All or Nothing Problem.

Robert Koons claims that my previous critique of his “new” cosmological argument is vitiated by confusion about the nature of defeasible argumentation.In response, I claim that Koons misrepresents—and perhaps misunderstands—the nature of my objections to his “new” cosmological argument. The main claims which I defend are: (1) that the move from a non-defeasible to a defeasible causal principle makes absolutely no difference to the success of the cosmological argument in which it is contained; and (2) that, since it is perfectly (...) well understood that non-theists have many reasons for rejecting the defeasible causal principle, it is pointless to claim that the move to a defeasible principle brings about a shift in the “burden of proof”. (Since some people may have forgotten—or may choose to ignore—the fact that non-theists do have reasons for rejecting the defeasible causal principle, I also provide a discussion of a modest sample of these reasons.). (shrink)

Introduction: The paper investigates the impact of the use of metaphors in reasoning tasks concerning vaccination, especially for defeasible reasoning cases. We assumed that both metaphor and defeasible reasoning can be relevant to let people understand vaccination as an important collective health phenomenon, by anticipating possible defeating conditions. -/- Methods: We hypothesized that extended metaphor could improve both the argumentative and the communicative effects of the message. We designed an empirical study to test our main hypotheses: participants (N = 196, (...) 78% females; Meanage = 27.97 years, SDage = 10.40) were presented with a text about vaccination, described in either literal or metaphorical terms, based on uncertain vs. safe reasoning scenarios. -/- Results: The results of the study confirmed that defeasible reasoning is relevant for the communicative impact of a text and that an extended metaphor enhances the overall communicative effects of the message, in terms of understandability, persuasion, perceived safety, and feeling of control over the health situation, collective trust in expertise and uptake of experts' advice. However, the results show that this effect is significantly nuanced by the type of defeasible reasoning, especially in the case of participants' trust in expertise and commitment to experts' advice. -/- Conclusion: Both communicative and defeasible reasoning competences are needed to enhance trust in immunization, with possible different outcomes at an individual and collective level. (shrink)

Two-step proportionality-balancing [TSPB] has become the standard method for human and constitutional rights decision-making. The first step consists in determining whether a rights-provision has been infringed/limited; if the answer to that first question is positive, the second step consists in determining whether the infringement/limit is reasonable or justified according to a proportionality analysis. TSPB has regularly been the target of some criticism. Critiques have argued that both its ‘two-step’ and ‘proportionality’ elements distort reality by promoting a false picture of rights (...) and constitutional decision-making. This would cause negative moral consequences. This article seeks to defend TSPB against these criticisms and to depict it in a more appropriate and favourable light. First, it is argued that both aspects of TSPB do not have the dire moral consequences that opponents suggest they have. Second, it is argued that TSPB, deploying notions such as burdens, presumptions and prima facie/defeasible propositions, constitutes a valuable framework for public argumentation and authoritative decision-making. (shrink)

This article offers a simple technical resolution to the problem of induction, which is to say that general facts are not always inferred from observations of particular facts, but are themselves sometimes defeasibly observed. The article suggests a holistic account of observation that allows for general statements in empirical theories to be interpreted as observation reports, in place of the common but arguably obsolete idea that observations are exclusively particular. Predictions and other particular statements about unobservable facts can then appear (...) as deductive consequences of such general observation statements, rather than inductive consequences of other particular statements. This semantic shift resolves the problem by eliminating induction as a basic form of inference, and folding the justification of general beliefs into the more basic problem of perception. (shrink)

This chapter lays out a case that with the proper perspective on the place of epistemology within normative inquiry more generally, it is possible to appreciate what was on the right track about some of the early approaches to the analysis of knowledge, and to improve on the obvious failures which led them to be rejected. Drawing on more general principles about reasons, their weight, and their relationship to justification, it offers answers to problems about defeat and the conditional fallacy (...) that plagued early defeasibility analyses of knowledge and offers a sketch of a contemporary alternative that is motivated by the idea that knowledge requires the right kind of “match” between objective and subjective factors. (shrink)

We present two defeasible logics of norm-propositions (statements about norms) that (i) consistently allow for the possibility of normative gaps and normative conflicts, and (ii) map each premise set to a sufficiently rich consequence set. In order to meet (i), we define the logic LNP, a conflict- and gap-tolerant logic of norm-propositions capable of formalizing both normative conflicts and normative gaps within the object language. Next, we strengthen LNP within the adaptive logic framework for non-monotonic reasoning in order to meet (...) (ii). This results in the adaptive logics LNPr and LNPm, which interpret a given set of premises in such a way that normative conflicts and normative gaps are avoided ‘whenever possible’. LNPr and LNPm are equipped with a preferential semantics and a dynamic proof theory. (shrink)

Accounts of arguments from expert opinion take it for granted that expert judgments count as (defeasible) evidence for propositions, and so an argument that proceeds from premises about what an expert judges to a conclusion that the expert is probably right is a strong argument. In Mizrahi (2013), I consider a potential justification for this assumption, namely, that expert judgments are significantly more likely to be true than novice judgments, and find it wanting because of empirical evidence suggesting that expert (...) judgments under uncertainty are not significantly more likely to be true than novice judgments or even chance. In this paper, I consider another potential justification for this assumption, namely, that expert judgments are not influenced by the cognitive biases novice judgments are influenced by, and find it wanting, too, because of empirical evidence suggesting that experts are vulnerable to pretty much the same cognitive biases that novices are vulnerable to. If this is correct, then the basic assumption at the core of accounts of arguments from expert opinion, namely, that expert judgments count as (defeasible) evidence for propositions, remains unjustified. (shrink)

I defend the thesis that friendship can constitutively require epistemic irrationality against a recent, forceful challenge, raised by proponents of moral and pragmatic encroachment. Defenders of the “encroachment strategy” argue that exemplary friends who are especially slow to believe that their friends have acted wrongly are simply sensitive to the high prudential or moral costs of falsely believing in their friends’ guilt. Drawing on psychological work on epistemic motivation (and in particular on the notion of “need for closure”), I propose (...) a different picture of what friendship requires in the doxastic realm. I argue that contrary to what the encroachment strategy suggests, exemplary friends’ belief formation ought not be guided by a concern with accuracy or error avoidance, but instead by a need to avoid a “specific closure” – namely, a need to avoid concluding in their friends’ guilt. I propose that exemplary friendship often generates a defeasible, doxastic obligation to exemplify such a need, despite its inherent corrupting effects on exemplary friends’ epistemic faculties. (shrink)

Ranking theory is one of the salient formal representations of doxastic states. It differs from others in being able to represent belief in a proposition (= taking it to be true), to also represent degrees of belief (i.e. beliefs as more or less firm), and thus to generally account for the dynamics of these beliefs. It does so on the basis of fundamental and compelling rationality postulates and is hence one way of explicating the rational structure of doxastic states. Thereby (...) it provides foundations for accounts of defeasible or nonmonotonic reasoning. It has widespread applications in philosophy, it proves to be most useful in Artificial Intelligence, and it has started to find applications as a model of reasoning in psychology. (shrink)

We propose a solution to the problem of logical omniscience in what we take to be its fundamental version: as concerning arbitrary agents and the knowledge attitude per se. Our logic of knowledge is a spin-off from a general theory of thick content, whereby the content of a sentence has two components: an intension, taking care of truth conditions; and a topic, taking care of subject matter. We present a list of plausible logical validities and invalidities for the logic of (...) knowledge per se for arbitrary agents, and isolate three explanatory factors for them: the topic-sensitivity of content; the fragmentation of knowledge states; the defeasibility of knowledge acquisition. We then present a novel dynamic epistemic logic that yields precisely the desired validities and invalidities, for which we provide expressivity and completeness results. We contrast this with related systems and address possible objections. (shrink)

I argue that semantics is the study of the proprietary database of a centrally inaccessible and informationally encapsulated input–output system. This system’s role is to encode and decode partial and defeasible evidence of what speakers are saying. Since information about nonlinguistic context is therefore outside the purview of semantic processing, a sentence’s semantic value is not its content but a partial and defeasible constraint on what it can be used to say. I show how to translate this thesis into a (...) detailed compositional-semantic theory based on the influential framework of Heim and Kratzer. This approach situates semantics within an independently motivated account of human cognitive architecture and reveals the semantics–pragmatics interface to be grounded in the underlying interface between modular and central systems. (shrink)

Many philosophers have been attracted to the view that reasons are premises of good reasoning – that reasons to φ are premises of good reasoning towards φ-ing. However, while this reasoning view is indeed attractive, it faces a problem accommodating outweighed reasons. In this article, I argue that the standard solution to this problem is unsuccessful and propose an alternative, which draws on the idea that good patterns of reasoning can be defeasible. I conclude by drawing out implications for the (...) debate over pragmatic reasons for belief and other attitudes and for one influential form of reductionism about the normative. (shrink)

This paper argues that public statues of persons typically express a positive evaluative attitude towards the subject. It also argues that states have duties to repudiate their own historical wrongdoing, and to condemn other people’s serious wrongdoing. Both duties are incompatible with retaining public statues of people who perpetrated serious rights violations. Hence, a person’s being a serious rights violator is a sufficient condition for a state’s having a duty to remove a public statue of that person. I argue that (...) this applies no less in the case of the ‘morally ambiguous’ wrongdoer, who both accomplishes significant goods and perpetrates serious rights violations. The duty to remove a statue is a defeasible duty: like most duties, it can be defeated by lesser-evil considerations. If removing a statue would, for example, spark a violent riot that would risk unjust harm to lots of people, the duty to remove could be outweighed by the duty not to foreseeably cause unjust harm. This would provide a lesser-evil justification for keeping the statue. But it matters that the duty to remove is outweighed, rather than negated, by these consequences. Unlike when a duty is negated, one still owes something in cases of outweighing. And it especially matters that it is outweighed by the predicted consequences of wrongful behaviour by others. (shrink)

I review recent work from armchair and cross-cultural epistemology on whether humans possess a knowledge concept as part of a universal “folk epistemology.” The work from armchair epistemology fails because it mischaracterizes ordinary knowledge judgments. The work from cross-cultural epistemology provides some defeasible evidence for a universal folk epistemology. I argue that recent findings from comparative psychology establish that humans possess a species-typical knowledge concept. More specifically, recent work shows that knowledge attributions are a central part of primate social cognition, (...) used to predict others’ behavior and guide decision-making. The core primate knowledge concept is that of truth detection (across different sensory modalities) and retention (through memory) and may also include rudimentary forms of indirect truth discovery through inference. In virtue of their evolutionary heritage, humans inherited the primate social-cognitive system and thus share this core knowledge concept. (shrink)

What if your peers tell you that you should disregard your perceptions? Worse, what if your peers tell you to disregard the testimony of your peers? How should we respond if we get evidence that seems to undermine our epistemic rules? Several philosophers have argued that some epistemic rules are indefeasible. I will argue that all epistemic rules are defeasible. The result is a kind of epistemic particularism, according to which there are no simple rules connecting descriptive and normative facts. (...) I will argue that this type of particularism is more plausible in epistemology than in ethics. The result is an unwieldy and possibly infinitely long epistemic rule — an Uber-rule. I will argue that the Uber-rule applies to all agents, but is still defeasible — one may get misleading evidence against it and rationally lower one’s credence in it. (shrink)

For the Intentionalist, utterance content is wholly determined by a speaker’s meaning-intentions; the sentence uttered serves merely to facilitate the audience’s recovering these intentions. We argue that Intentionalists ought to be Particularists, holding that the only “principles” of meaning recovery needed are those governing inferences to the best explanation; “principles” that are both defeasible and, in a sense to be elaborated, variable. We discuss some ways in which some theorists have erred in trying to tame the “wild west” of pragmatics (...) and context-sensitivity -- including recent work that makes essential appeal to the information structure of a discourse -- and in so doing, offer a general recipe for defending the Particularist picture of utterance content and its recovery that we favor. (shrink)

From the early reception of Thomas Aquinas up to the present, many have interpreted his theory of liberum arbitrium to imply intellectual determinism: we do not control our choices, because we do not control the practical judgments that cause our choices. In this paper we argue instead that he rejects determinism in general and intellectual determinism in particular, which would effectively destroy liberum arbitrium as he conceives of it. We clarify that for Aquinas moral responsibility presupposes liberum arbitrium and thus (...) the ability to do otherwise, although the ability to do otherwise applies differently to praise and blame. His argument against intellectual determinism is not straightforward, but we construct it by analogy to his arguments against other deterministic threats. The non-determinism of the intellect’s causality with respect to the will results from his claims that practical reasoning is defeasible and that the reasons for actions are not contrastive reasons. (shrink)

This paper offers a simple and novel motivation for the Humean Theory of Reasons. According to the Humean Theory of Reasons, all reasons must be explained by some psychological state of the agent for whom they are reasons, such as a desire. This view is commonly thought¹ to be motivated by a substantive theory about the power of reasons to motivate known as reason internalism, and a substantive theory about the possibility of being motivated without a desire known as the (...) Humean Theory of Motivation. Such a motivation would place substantial constraints on what form the Humean Theory of Reasons might take, and incur substantial commitments in metaethics and moral psychology. The argument offered here, on the other hand, is based entirely on relatively uncontroversial methodological considerations of perfectly broad applicability, and on the commonplace observation that while some reasons are reasons for anyone, others are reasons for only some. The argument is a highly defeasible one, but is supposed to give us a direct insight into what is philosophically deep about the puzzles raised for ethical theory by the Humean Theory of Reasons. I claim that it should renew our interest in the relationship between these two kinds of reason, and in particular in the explanation of reasons which seem to depend on desires or other psychological states. (shrink)

This paper presents an alternative to the standard view that the evaluations that the so-called "thick" terms and concepts in ethics may be used to convey belong to their sense or semantic meaning. I describe a large variety of linguistic data that are well explained by the alternative view that the evaluations that (at least a very wide range of) thick terms and concepts may be used to convey are a certain kind of defeasible implications of their utterances which can (...) be given a conversational explanation. I then provide some reasons to think that this explanation of the data is superior to the standard view, but a fuller assessment must await further work. In closing I briefly survey the largely deflationary consequences of this account regarding the significance of thick terms and concepts for evaluative thought and judgment. (shrink)

How, if at all, is knowing how to do something defeasible? Some, the “intellectualists”, treat the defeasibility of knowledge-how as in some way derivative on the defeasibility of knowledge-that. According to a recent proposal by Carter and Navarro (Philos Phenomenol Res 3:662–685, 2017), knowledge-how defeat cannot be explained in terms of knowledge-that defeat; instead, knowledge-how defeat merits and entirely separate treatment. The thought behind “separatism” is easy to articulate. Assuming that knowledge of any kind is defeasible, since knowledge-that (...) and knowledge-how are fundamentally different beasts, the best accounts of their defeasibility must reflect the underlying differences between them. I reject a separatist treatment of the defeasibility of knowledge-that and knowledge-how. One can acknowledge certain important differences between knowledge-that and knowledge-how without thereby needing two theories of defeasibility. Ultimately, though, I’ll argue that the defeasibility of basic knowledge-how, unlike non-basic knowledge-how, is a much more difficult issue than has been acknowledged. (shrink)

The Enkratic Principle enjoys something of a protected status as a requirement of rationality. I argue that this status is undeserved, at least in the epistemic domain. Compliance with the principle should not be thought of as a requirement of epistemic rationality, but rather as defeasible indication of epistemic blamelessness. To show this, I present the Puzzle of Inconsistent Requirements, and argue that the best way to solve it is to distinguish two kinds of epistemic evaluation – requirement evaluations and (...) appraisal evaluations. This allows us to solve the puzzle while accommodating traditional motivations for thinking of the Enkratic Principle as a requirement of rationality. (shrink)