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)

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)

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)

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 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)

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)

This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. (...) Results contrast with, and may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align. (shrink)

This paper explains the importance of classifying argumentation schemes, and outlines how schemes are being used in current research in artificial intelligence and computational linguistics on argument mining. It provides a survey of the literature on scheme classification. What are so far generally taken to represent a set of the most widely useful defeasible argumentation schemes are surveyed and explained systematically, including some that are difficult to classify. A new classification system covering these centrally important schemes is built.

In this paper it is shown how certain defeasible argumentation schemes can be used to represent the logical structure of the most common types of argument used for statutory interpretation both in civil and common law. The method is based on an argumentation structure in which the conclusion, namely, the meaning attributed to a legal source, is modeled as a claim that needs that is be supported by pro and con defeasible arguments. The defeasible nature of (...) each scheme is shown by means of critical questions, which identify the default conditions for the accepting interpretative arguments and provide a method for evaluating a given argument as weak or strong. (shrink)

This paper explains the importance of classifying argumentation schemes, and outlines how schemes are being used in current research in artificial intelligence and computational linguistics on argument mining. It provides a survey of the literature on scheme classification. What are so far generally taken to represent a set of the most widely useful defeasible argumentation schemes are surveyed and explained systematically, including some that are difficult to classify. A new classification system covering these centrally important schemes is built.

This paper explains the importance of classifying argumentation schemes, and outlines how schemes are being used in current research in artificial intelligence and computational linguistics on argument mining. It provides a survey of the literature on scheme classification. What are so far generally taken to represent a set of the most widely useful defeasible argumentation schemes are surveyed and explained systematically, including some that are difficult to classify. A new classification system covering these centrally important schemes is built.

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)

This paper argues for a reinterpretation of Aristotle's concept of an enthymeme and also his wider informal logic in terms of arguments that are defeasible. They are represented by forms of argument that are called argumentation schemes, considered to be similar to forms of argument found in deductive logic, but different from the foregoing in virtue of their being defeasible. Indeed, the most interesting schemes have been put forward as a helpful way of characterizing structures of (...) human reasoning that have proved troublesome to model deductively. The paper sheds new light on Aristotle's topics and how to dene `enthymeme'. If the traditional denition of an enthymeme in logic accepted for over two thousand years is a misnomer, the question is raised whether we ought to redene it as a defeasible argumentations scheme or leave things as they are. (shrink)

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)

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)

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)

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)

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)

Over the past decade or so, a new interdisciplinary field has emerged in the ground between, on the one hand, computer science – and artificial intelligence in particular – and, on the other, the area of philosophy concentrating on the language and structure of argument. There are now hundreds of researchers worldwide who would consider themselves a part of this nascent community. Various terms have been proposed for the area, including "Computational Dialectics," "Argumentation Technology," and "Argument-based Computing," but (...) the term that has stuck is simply Argument & Computation. It encompasses several specific strands of research, such as: . the use of theories of argument, and dialectic in particular, in the design and implementation of protocols for multi-agent action and communication; . the application of theories of argument and rhetoric in natural language processing and affective computing; . the use of argument-based structures for autonomous reasoning in artificial intelligence, and in particular, for defeasible reasoning; . computer-supported collaborative argumentation – the implementation of software tools for enabling online argument in domains such as education and e-government. These strands come together to form the core of a research field that covers parts of artificial intelligence (AI), philosophy, linguistics, and cognitive science, but, increasingly, is building an identity of its own. (shrink)

In this paper, we use concepts, structure and tools from argumentation theory to show how conversational implicatures are triggered by conflicts of presumptions. Presumptive implicatures are shown to be based on defeasible forms of inference used in conditions of lack of knowledge, including analogical reasoning, inference to the best explanation, practical reasoning, appeal to pity, and argument from cause. Such inferences are modelled as communicative strategies to knowledge gaps that shift the burden of providing the missing contrary evidence (...) to the other party in a dialogue. Through a series of illustrative examples, we show how such principles of inference are based on common knowledge about the ordinary course of events shared by participants in a structured dialogue setting in which they take turns putting forward and responding to speech acts. (shrink)

This paper analyzes selected examples of uses of argumentation tactics that exploit emotive language, many of them criticized as deceptive and even fallacious by classical and recent sources, including current informal logic textbooks. The analysis is based on six argumentation schemes, and an account of the dialectical setting in which these schemes are used. The three conclusions are (1) that such uses of emotive language are often reasonable and necessary in argumentation based on values, (2) but that they are (...) class='Hi'>defeasible, and hence need to be seen as open to critical questioning (3) and that when they are used fallaciously, it is because they interfere with critical questioning or conceal the need for it. The analysis furnishes criteria for distinguishing between arguments based on the use of emotive words that are reasonable tools of persuasion, and those that are fallacious tactics used to conceal and distort information. (shrink)

The paper considers contemporary models of presumption in terms of their ability to contribute to a working theory of presumption for argumentation. Beginning with the Whatelian model, we consider its contemporary developments and alternatives, as proposed by Sidgwick, Kauffeld, Cronkhite, Rescher, Walton, Freeman, Ullmann-Margalit, and Hansen. Based on these accounts, we present a picture of presumptions characterized by their nature, function, foundation and force. On our account, presumption is a modal status that is attached to a claim and has the (...) effect of shifting, in a dialogue, a burden of proof set at a local level. Presumptions can be analysed and evaluated inferentially as components of rule-based structures. Presumptions are defeasible, and the force of a presumption is a function of its normative foundation. This picture seeks to provide a framework to guide the development of specific theories of presumption. (shrink)

Some animal defenders are committed to complete abstinence from animal products. However the strongest arguments for adopting veganism only seem to require that one avoid using animal products, where use or procurement of these products will harm sentient animals. As such, there is seemingly a gap between our intuition and our argument. In this article I attempt to defend the more comprehensive claim that we have a moral reason to avoid using animal products, regardless of the method of procurement. (...) I argue that animal bodies give rise to properties which grant sentient animals’ moral status and in light of this, animal bodies possess final value in themselves. This final value gives us a moral reason not to commodify animal bodies, which means we have a defeasible reason to abstain from using animal products in almost all circumstances. (shrink)

This chapter proposes a dialectical approach to legal interpretation, consisting of three dimensions: a formalization of the canons of interpretation in terms of argumentation schemes; a dialectical classification of interpretive schemes; and a logical and computational model for comparing the arguments pro and contra an interpretation. The traditional interpretive maxims or canons used in both common and civil law are translated into defeasible patterns of arguments, which can be evaluated through sets of corresponding critical questions. These interpretive argumentation schemes (...) are classified in general categories and a distinction is drawn between schemes supporting and rebutting an interpretation. This framework allows conceiving statutory interpretation as a dialectical procedure consisting in weighing arguments pro and contra an interpretation. This procedure is formalized and represented computationally through tools from formal argumentation systems. (shrink)

We argue that common knowledge, of the kind used in reasoning in law and computing is best analyzed using a dialogue model of argumentation (Walton & Krabbe 1995). In this model, implicit premises resting on common knowledge are analyzed as endoxa or widely accepted opinions and generalizations (Tardini 2005). We argue that, in this sense, common knowledge is not really knowledge of the kind represent by belief and/or knowledge of the epistemic kind studied in current epistemology. This paper takes a (...) different approach, defining it in relation to a common commitment store of two participants in a rule-governed dialogue in which two parties engage in rational argumentation (Jackson & Jacobs 1980; van Eemeren & Grootendorst 2004). A theme of the paper is how arguments containing common knowledge premises can be studied with the help of argumentation schemes for arguments from generally accepted opinion and expert opinion. It is argued that common knowledge is a species of provi- sional acceptance of a premise that is not in dispute at a given point in a dia- logue, but may later be defeated as the discussion proceeds . (shrink)

Hume’s argument against believing the testimony of miracles is the most influential treatment of the topic, but there is not yet a consensus on how to interpret his argument. Two arguments are attributed to him. First, Hume seems to start with the infrequency of miracles and uses this to infer that the testimony of a miracle is exceedingly unlikely, and this then creates strong but defeasible evidence against the testimony of any miracle. Second, perhaps Hume takes the (...) constancy of our experience of the laws of nature as decisive or indefeasible evidence against the testimony of any miracle. I explain the basis for each of these interpretations of Hume’s argument, and then develop a novel criticism of his view: namely, any inductive inference depends on the relevant similarity between the observed and the unobserved, but we may have reason for thinking that purported miracles are not relevantly similar, and thus our past experience cannot be used as reliable evidence about the testimony of (some) miracles. (shrink)

J. L. Schellenberg, in “A New Logical Problem of Evil,” published in The Blackwell Companion to the Problem of Evil, argues that (if God exists) God has, of necessity, a disappreciation of evil, operating at a metalevel in such a way as to give God a non-defeasible reason to rule out actualizing a world containing evil. He also argues that since God’s motive in creating the world is to share with finite beings the good that God experiences prior to (...) creation, which is good without evil, it follows that God will create a world that contains no evil. I investigate in detail the foregoing lines of argument and provide grounds for rejecting them. My paper is published in Vol 38 No.2, whose date is nominally April 2021 although the issue is not in fact available yet. (shrink)

This paper explains how to use a new software tool for argument diagramming available free on the Internet, showing especially how it can be used in the classroom to enhance critical thinking in philosophy. The user loads a text file containing an argument into a box on the computer interface, and then creates an argument diagram by dragging lines from one node to another. A key feature is the support for argumentation schemes, common patterns of defeasible (...) reasoning historically know as topics . Several examples are presented, as well as the results of an experiment in using the system with students in a university classroom. (shrink)

Many have offered moral objections to video games, with various critics contending that they depict and promote morally dubious attitudes and behaviour. However, few have offered moral arguments in favour of video games. In this chapter, we develop one such positive moral argument. Specifically, we argue that video games offer one of the only morally acceptable methods for acquiring some ethical knowledge. Consequently, we have (defeasible) moral reasons for creating, distributing, and playing certain morally educating video games.

Those of us who enjoy certain products of the global industrial economy but also believe it is wrong to consume them are often so demoralized by the apparent inefficacy of our individual, private choices that we are unable to resist. Although he was a deontologist, Kant was clearly aware of this ‘consequent-dependent’ side of our moral psychology. One version of his ‘moral proof’ is designed to respond to the threat of such demoralization in pursuit of the Highest Good. That version (...) of the argument says that the capacity that faith and trust in God has to sustain our moral resolve licenses that faith and trust, from a practical point of view. My goal here is to argue that Kant’s proof has a contemporary, secular analogue in modern industrial contexts where the apparent “inefficacy” of an individual consumer’s choices in the face of massive insensitive supply-chains is a threat to her moral resolve. I conclude by suggesting that the Kantian approach may license us in adopting (as an item of defeasible moral faith) an evidential decision-theoretic principle regarding what it is to ‘make a difference.’ This in turn licenses trust -- if not in God then in other right-minded people. (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)

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)

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)

This paper investigates the emotive (or expressive) meaning of words commonly referred to as “loaded” or “emotive,” which include slurs, derogative or pejorative words, and ethical terms. We claim that emotive meaning can be reinterpreted from a pragmatic and argumentative perspective, which can account for distinct aspects of ethical terms, including the possibility of being modified and its cancellability. Emotive meaning is explained as a defeasible and automatic or automatized evaluative and intended inference commonly associated with the use of (...) specific terms, which can be represented and assessed considering its logical structure and its defeasibility conditions. This automatic inference is conceived as part of the connotation of an ethical term, and is not necessarily stable. By means of quasi-definitions, it is possible to modify the emotive meaning while maintaining the descriptive one, automaticizing the inferences drawn from an ethical word. Through examples drawn from the recent US presidential campaign, we show how re-contextualization and emotive contexts can affect emotive meaning. (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)

Descartes's "conceivability argument" for substance-dualism is defended against Arnauld's criticism that, for all he knows, Descartes can conceive himself without a body only because he underestimates his true essence; one could suggest with equal plausibility that it is only for ignorance of his essential hairiness that Descartes can conceive himself as bald. Conceivability intuitions are defeasible but special reasons are required; a model for such defeat is offered, and various potential defeaters of Descartes's intuition are considered and rejected. (...) At best though Descartes shows the separability of mind from body, not (as he claims) their actual separateness. (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)

A growing number of authors defend putative examples of knowledge from falsehood (KFF), inferential knowledge based in a critical or essential way on false premises, and they argue that KFF has important implications for many areas of epistemology (whether evidence can be false, the Gettier debate, defeasibility theories of knowledge, etc.). I argue, however, that there is no KFF, because in any supposed example either the falsehood does not contribute to the knowledge or the subject lacks knowledge. In particular, I (...) show that if the subject actually has knowledge in putative KFF cases, then there is always a veridical evidential path meeting the basing conditions that accounts for her knowledge; if there is no such path, then the subject is in a type of Gettier case. All the recent arguments that rely on KFF are therefore based on a mistake. (shrink)

This paper advances an approach to relevance grounded on patterns of material inference called argumentation schemes, which can account for the reconstruction and the evaluation of relevance relations. In order to account for relevance in different types of dialogical contexts, pursuing also non-cognitive goals, and measuring the scalar strength of relevance, communicative acts are conceived as dialogue moves, whose coherence with the previous ones or the context is represented as the conclusion of steps of material inferences. Such inferences are described (...) using argumentation schemes and are evaluated by considering 1) their defeasibility, and 2) the acceptability of the implicit premises on which they are based. The assessment of both the relevance of an utterance and the strength thereof depends on the evaluation of three interrelated factors: 1) number of inferential steps required; 2) the types of argumentation schemes involved; and 3) the implicit premises required. (shrink)

Most advanced industrial societies are ‘work-centered,’ according high value and prestige to work. Indeed, belief in an interpersonal moral duty to work is encoded in both popular attitudes toward work and in policies such as ‘workfare’. Here I argue that despite the intuitive appeal of reciprocity or fair play as the moral basis for a duty to work, the vast majority of individuals in advanced industrialized societies have no such duty to work. For current economic conditions, labor markets, and government (...) policies entail that the conditions for a reciprocity-based argument to apply to most workers are not usually met. More specifically, many workers fail to provide valuable goods through working or their working does not result in net social benefit. Concurrently, many workers do not receive adequate benefits from working in that they neither have their basic needs met or do not even enjoy an improvement in welfare thanks to working. Hence, workers neither provide nor receive the benefits needed for a reciprocity-based duty to work to apply to them. Furthermore, these conditions are conditions over which workers themselves have very little control. Most workers therefore could not fulfill their ostensible duty to work even if they made conscientious efforts to do so. In most cases, a person who fails to work morally wrongs no one, and in the case of any particular individual or worker, the defeasible presumption ought to be that she has no duty to work. (shrink)

The fields of linguistic pragmatics and legal interpretation are deeply interrelated. The purpose of this paper is to show how pragmatics and the developments in argumentation theory can contribute to the debate on legal interpretation. The relation between the pragmatic maxims and the presumptions underlying the legal canons are brought to light, unveiling the principles that underlie the types of argument usually used to justify a construction. The Gricean maxims and the arguments of legal interpretation are regarded as presumptions (...) subject to default used to justify an interpretation. This approach can allow one to trace the different legal interpretive arguments back to their basic underlying presumptions, so that they can be compared, ordered, and assessed according to their defeasibility conditions. This approach allows one to understand the difference between various types of interpretive canons, and their strength in justifying an interpretation. (shrink)

Given that conspiracies exist, can we be justified in dismissing conspiracy theories without concerning ourselves with specific details? I answer this question by focusing on contrarian conspiracy theories, theories about conspiracies that conflict with testimony from reliable sources of information. For example, theories that say the CIA masterminded the assassination of John F. Kennedy, 9/11 was an inside job, or the Freemasons are secretly running the world are contrarian conspiracy theories. When someone argues for a contrarian conspiracy theory, their options (...) are to appeal to eyewitness testimony, incriminating documents, photographs, audio recordings, video recordings, allegedly scientific evidence, anomalies, or considerations of cui bono (who benefits). Most laypeople don’t know how to adequately respond to arguments for contrarian conspiracy theories, but this doesn’t mean that it’s dogmatic to reject them. I argue that many laypeople are defeasibly justified in rejecting a variety of contrarian conspiracy theories based on testimony and this justification is rarely defeated by arguments for contrarian conspiracy theories even if we don’t know how to respond to these arguments. (shrink)

Proponents of vaccine mandates typically claim that everyone who can be vaccinated has a moral or ethical obligation to do so for the sake of those who cannot be vaccinated, or in the interest of public health. I evaluate several previously undertheorised premises implicit to the ‘obligation to vaccinate’ type of arguments and show that the general conclusion is false: there is neither a moral obligation to vaccinate nor a sound ethical basis to mandate vaccination under any circumstances, even for (...) hypothetical vaccines that are medically risk-free. Agent autonomy with respect to self-constitution has absolute normative priority over reduction or elimination of the associated risks to life. In practical terms, mandatory vaccination amounts to discrimination against healthy, innate biological characteristics, which goes against the established ethical norms and is also defeasible a priori. (shrink)

Many epistemologists have responded to the lottery paradox by proposing formal rules according to which high probability defeasibly warrants acceptance. Douven and Williamson present an ingenious argument purporting to show that such rules invariably trivialise, in that they reduce to the claim that a probability of 1 warrants acceptance. Douven and Williamson’s argument does, however, rest upon significant assumptions – amongst them a relatively strong structural assumption to the effect that the underlying probability space is both finite and (...) uniform. In this paper, I will show that something very like Douven and Williamson’s argument can in fact survive with much weaker structural assumptions – and, in particular, can apply to infinite probability spaces. (shrink)

In this paper, we discuss an abductive argument for the existence of God from the experience of awe at natural beauty. If God's creative work is a viable explanation for why we experience awe at natural beauty, and there is no satisfactory naturalistic explanation for the origins of such experiences, then we have defeasible evidence that God exists. To evaluate the argument's tenability, we assess the merits of the two main theocentric frameworks that can be marshaled to (...) answer the question of why human beings experience awe at natural beauty: (1) taking the experience of natural beauty as resulting from God's design intentions and (2) conceiving experiences of natural beauty as religious experiences in themselves. We argue that the presence of phenomenological content the fine-grainedness of which exceeds our descriptive and conceptual capacities is better accounted for by the latter hypothesis: experiencing natural beauty amounts to experiencing divine attributes. We conclude that the argument's theological premise is tenable and, having previously argued for the empirical premise (Porcher & De Luca-Noronha, 2021), we conclude that awe at natural beauty is best explained by the existence of God. (shrink)

I discuss the role of translatability in philosophical justification. I begin by discussing and defending Thomas Reid’s account of the role that facts about comparative linguistics can play in philosophical justification. Reid believes that common sense offers a reliable but defeasible form of justification. We cannot know by introspection, however, which of our judgments belong to common sense. Judgments of common sense are universal, and so he argues that the strongest evidence that a judgment is a part of common (...) sense is that it is to be found in all languages. For Reid, then, evidence that a certain distinction is to be found in all languages is evidence that the distinction is part of common sense rather than being a common local prejudice. From such a perspective, empirical work in comparative linguistics can play a defeasible justificatory role in philosophical arguments. I contrast Reid’s position with the more radical position of defenders of the Natural Semantic Metalanguage approach, such as Anna Wierzbicka, who argues that only judgments that are translatable into all natural languages are justifiable. I show how such a position is rooted in an implausible view, although one common among cognitive scientists and linguistics, about the nature of concepts, which does not allow for novel concepts. (shrink)

We argue that individual and institutional caregivers have a defeasible moral duty to provide dependent children with plant-based diets and related education. Notably, our three arguments for this claim do not presuppose any general duty of veganism. Instead, they are grounded in widely shared intuitions about children’s interests and caregivers’ responsibilities, as well as recent empirical research relevant to children’s moral development, autonomy development, and physical health. Together, these arguments constitute a strong cumulative case against inculcating in children the (...) dietary practice of regularly eating meat (and other animal products)—a practice we call “carnism.”. (shrink)

In this paper, I endorse the idea that age is a defensible criterion for eligibility to vote, where age is itself a proxy for having a broad set of cognitive and motivational capacities. Given the current (and defeasible) state of developmental research, I suggest that the age of 16 is a good proxy for such capacities. In defending this thesis, I consider alternative and narrower capacity conditions while drawing on insights from a parallel debate about capacities and age requirements (...) in the criminal law. I also argue that the expansive capacity condition I adopt satisfies a number of powerful and complementary rationales for voting eligibility, and conclude by addressing challenging arguments that, on the one hand, capacity should not underlie voting eligibility in the first place, and, on the other, that capacity should do so directly and not via any sort of proxy, including age. (shrink)

This paper addresses two questions about audience misunderstandings of contemporary art. First, what is the institution’s responsibility to prevent predictable misunderstandings about the nature of a contemporary artwork, and how should this responsibility be balanced against other considerations? Second, can an institution ever be justified in intentionally mounting an inauthentic display of an artwork, given that such displays are likely to mislead? I will argue that while the institution has a defeasible responsibility to mount authentic displays, this is not (...) always sufficient to avoid misunderstanding; the institution will sometimes need to supply auxiliary information. And even where competing considerations require mounting an inauthentic display, thoughtful museum practice can promote the audience’s ability to grasp the work. The argument will be developed with consideration of artworks by El Anatsui, Lygia Clark, and Glenn Ligon. (shrink)