A discussion of epistemic reasons, theoretical rationality, and the relationship between them. Discusses the ontology of reasons and evidence, the relationship between reasons (motivating, normative, possessed, apparent, genuine, etc.) and rationality, the relationship between epistemic reasons and evidence, the relationship between rationality, justification, and knowledge, and many other related topics.

Deontic Doxastic Constitutivism is the view that beliefs are constitutively governed by deontic norms. This roughly means that a full account and understanding of the nature of these mental attitudes cannot be reached unless one appeals to some norm of this type. My aim in this article is to provide an objection to such a conception of the normativity of belief. I argue that if some deontic norm is constitutive of belief, then the addressees of such a norm are committed (...) to a potentially infinite number of norms. Furthermore, if addressees are in the position to fulfill all such norms, they must also be able to hold a potentially infinite number of logically independent beliefs. Both these consequences are problematic if compared with limited human capacities to act and believe. (shrink)

I argue that its appearing to you that P does not provide justification for believing that P unless you have independent justification for the denial of skeptical alternatives – hypotheses incompatible with P but such that if they were true, it would still appear to you that P. Thus I challenge the popular view of ‘dogmatism,’ according to which for some contents P, you need only lack reason to suspect that skeptical alternatives are true, in order for an experience as (...) of P to justify belief that P. I pursue three lines of objection to dogmatism, having to do with probabilistic reasoning, considerations of future or hypothetically available justification, and epistemic circularity. I briefly sketch a fall-back position which avoids the problems raised. (shrink)

In previous work, I have suggested a doxastic account of perceptual experience according to which experiences form a kind of belief: Beliefs with what I have called “phenomenal” or “looks-content”. I have argued that this account can not only accommodate the intuitive reason providing role of experience, but also its justificatory role. I have also argued that, in general, construing experience and perceptual beliefs, i.e. the beliefs most directly based on experience, as having different contents best accounts for the defeasibility (...) of experiential reasons. In this paper, I shall have a closer look at the evidential or inferential relation between looks-propositions and the contents of perceptual beliefs and argue for a form of what I shall call “Pollockianism” about experiential reasons: such reasons are good unless defeated. Questions to be investigated include: Does the resulting picture of perceptual justification contain an externalist element? Is it compatible with Bayesianism? And how does it do with respect to problems that have been raised for other forms of Pollockianism such as dogmatism or phenomenal conservatism? (shrink)

Imagine I hold up a Granny Smith apple for all to see. You would thereby gain justified beliefs that it was green, that it was apple, and that it is a Granny Smith apple. Under classical foundationalism, such simple visual beliefs are mediately justified on the basis of reasons concerning your experience. Under dogmatism, some or all of these beliefs are justified immediately by your experience and not by reasons you possess. This paper argues for what I call the looks (...) view of the justification of simple visual beliefs. According to the looks view, such beliefs are mediately justified on the basis of reasons concerning how the relevant things look. Unlike under classical foundationalism, under the looks view as I develop it, these reasons are public. They are public with respect to both their content and possession: with respect to content, they are not about ourselves and our experiences, and with respect to their possession, many people can have the very same looks-related reasons. (shrink)

If our experiences are cognitively penetrable, they can be influenced by our antecedent expectations, beliefs, or other cognitive states. Theorists such as Churchland, Fodor, Macpherson, and Siegel have debated whether and how our cognitive states might influence our perceptual experiences, as well as how any such influences might affect the ability of our experiences to justify our beliefs about the external world. This article surveys views about the nature of cognitive penetration, the epistemological consequences of denying cognitive penetration, and the (...) epistemological consequences of affirming cognitive penetration. (shrink)

Nearly everyone agrees that perception gives us justification and knowledge, and a great number of epistemologists endorse a particular two-part view about how this happens. The view is that perceptual beliefs get their justification from perceptual experiences, and that they do so by being based on them. Despite the ubiquity of these two views, I think that neither has very much going for it; on the contrary, there’s good reason not to believe either one of them.

While such epistemic rules as 'If you perceive that X, you ought to believe that X' and 'If you have outstanding testimony that X, you ought to believe that X' seem to be getting at important truths, it is easy to think of cases in which they come into conflict. To avoid classifying such cases as dilemmas, one can hold either that epistemic rules have built-in unless-clauses listing the circumstances under which they don't apply, or, alternatively, that epistemic rules are (...) contributory. This paper explores both responses from a formal perspective, drawing on a simple defeasible logic framework. (shrink)

This paper argues that no instances of acquiring knowledge from works of literary fiction are instances of the way we ordinarily learn from the testimony of others. The paper argues that the fictional status of a work is a defeater for the justification of beliefs formed on the basis of statements within that work, which must itself be defeated for such beliefs based on fiction to amount to knowledge. This marks a fundamental difference with learning from testimony, since regardless of (...) one's views on testimony and testimonial knowledge, the fact that your belief that p was based on someone's testimony that p is not in and of itself a defeater for your justification for believing that p. (shrink)

Inference is a process by which appropriate belief states get connected. Belief states are biological states in the sense that they are reentrant loops ; their intrinsic feature is recognition. In inference or reasoning the transition process between belief states is regulated by the rule of concept usage, involved in the belief state, in natural language. Like belief states experiential states are also biological states whose extrinsic feature is recognition, such that, one can have an, say, X-type experience without recognizing (...) it as an experience of X. One can, however, also have an experience of an X; in the latter case, one not only has an X-type experience but also recognizes an X as an X. In some cases the transition from X-type experience to believing an X to be there instantiates a quasi-inferential pattern. In all such cases the transition process is regulated by the rule of X usage. In such quasi-inferential transition additional belief states are involved. Such states assert that there are no countervailing factors and there are additional factors conducive to the conclusion. Such belief states are expressed non-propositionally in the language of thought. Propositions are a necessary part of such quasi-inference for they give content to thoughts to which one can assign 'falsity' and defeasible reasoning requires us to assign 'falsity' to our thoughts. Propositions implicated in the quasi-inferences from experience types to belief states are the evidential reasons for the conclusion and they can only be accepted as provisionally true and have to be revised in the light of further information. (shrink)

Bootstrapping is a suspicious form of reasoning that verifies a source's reliability by checking it against itself. Theories that endorse such reasoning face the bootstrapping problem. This article considers which theories face the problem, and surveys potential solutions. The initial focus is on theories like reliabilism and dogmatism, which allow one to gain knowledge from a source without knowing that it is reliable. But the discussion quickly turns to a more general version of the problem that does not depend on (...) this allowance. Five potential solutions to the general problem are evaluated, and some implications for the literature on peer disagreement are considered. (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)

Defeasible reasoning is concerned with the logics of non-deductive argument. As is described in the literature, the study of this type of reasoning is considerably more involved than the study of deductive argument, even so that, in realistic applications, there is often a lack of resources to perform an exhaustive analysis. It follows that, in a theory of defeasible reasoning, the order and direction in which arguments are developed, i.e. theprocedure, is important. The aim of this article is to show (...) that debate is the most efficient procedure to argue in the presence of limited resources. To do so, there is first some general theory on defeasible argumentation, which is followed by an introduction to the problem of dialectical search. The problem of dialectical search is (or at least, should be) the essential issue in every theory on argumentation, and emerges at every occasion that involves adjudication on competing arguments. Starting with an example, it is explained that dialectical search can be best scheduled according to classical debating techniques, that work along well-tried methods. These methods (which include various forms of curtailment, interruption, and interpretation) have proven their value in keeping debating efforts within reasonable bounds. How they apply in a theory of formal argument, will be shown in this article. (shrink)

Epistemic and practical interests are often in conflict. This also occurs in institutional settings such as the legal one. Rule 407 of the U.S. Federal Rules of Evidence is an example of that because it sacrifices some epistemic interests in favour of practical ones. It is the rule on subsequent remedial measures (SRM), which is mainly designed to answer a practical concern (reducing accidents) instead of the epistemic one of getting some evidence to find out whether the defendant was negligent (...) or whether there was a defect in a product. Some commentators and courts think that the rationale of the rule is more complex and deserves a more careful discussion, as this paper shows. Additionally, this paper discusses a modification proposal (from categorical ban of SRM evidence to case‐by‐case decision) and develops some theoretical considerations, in the spirit of philosophical pragmatism, on the best way to conceptualize the problem addressed. The idea is to see such conflicts as conflicts of goals and to explain them in terms of the incompatible desires that we happen to have. (shrink)

Contemporary philosophers are attracted by the Indispensability Claim, according to which emotions are indispensable in acquiring knowledge of some important values. The truth of this claim is often thought to depend on that of Emotional Dogmatism, the view that emotions justify evaluative judgements because they (seem to) make us aware of the relevant values. The aim of this paper is to show that the Indispensability Claim does not stand or fall with Emotional Dogmatism and that there is actually an attractive (...) alternative way of developing it. We first argue that the Indispensability Claim requires a deflationary account of the cognitive bases of emotions, which we call the Simple View and defend against a variety of criticisms. Armed with the Simple View, we show that the Indispensability Claim is made true by three roles of the emotions: they help us access the relevant evidence, provide a needed hook-up between evidence and judgement, and contribute to evaluative understanding. (shrink)

W. V. Quine famously claimed that no statement is immune to revision. This thesis has had a profound impact on twentieth century philosophy, and it still occupies centre stage in many contemporary debates. However, despite its importance it is not clear how it should be interpreted. I show that the thesis is in fact ambiguous between three substantially different theses. I illustrate the importance of clarifying it by assessing its use in the debate against the existence of a priori knowledge. (...) I show how the three different readings of the thesis can be used to generate three substantially different and philosophically significant arguments against the a priori. I further challenge each one of these arguments against the a priori. (shrink)

This paper is an opinionated guide to the literature on normative epistemic reasons. After making some distinctions in §1, I begin in §2 by discussing the ontology of normative epistemic reasons, assessing arguments for and against the view that they are mental states, and concluding that they are not mental states. In §3, I examine the distinction between normative epistemic reasons there are and normative epistemic reasons we possess. I offer a novel account of this distinction and argue that we (...) in fact ought to acknowledge a threefold distinction between objective, possessed, and apparent normative epistemic reasons. In §4, I discuss the question of which normative reasons for doxastic attitudes are the epistemic ones, evaluating reasons against a simple evidentialist answer. Finally, in §5, I look at the role of reasons in epistemology, considering challenges to viewing reasons as the building blocks of epistemic normativity and maintaining that the challenges recommend a novel bi-level epistemology rather than a marginalization of reasons in epistemology. (shrink)

Titelbaum Oxford studies in epistemology, 2015) has recently argued that the Enkratic Principle is incompatible with the view that rational belief is sensitive to higher-order defeat. That is to say, if it cannot be rational to have akratic beliefs of the form “p, but I shouldn’t believe that p,” then rational beliefs cannot be defeated by higher-order evidence, which indicates that they are irrational. In this paper, I distinguish two ways of understanding Titelbaum’s argument, and argue that neither version is (...) sound. The first version can be shown to rest on a subtle, but crucial, misconstrual of the Enkratic Principle. The second version can be resisted through careful consideration of cases of higher-order defeat. The upshot is that proponents of the Enkratic Principle are free to maintain that rational belief is sensitive to higher-order defeat. (shrink)

A central metaphilosophical project seeks to evaluate the reliability of the types of evidence that figure in philosophical arguments and, relatedly, the justificatory status of relying on those types of evidence. Traditionally, metaphilosophers have approached this project via an analysis of intuition. This article argues that the category picked out by “intuition” is both too broad and too heterogeneous to serve as the appropriate target for metaphilosophical inquiry. Intuition is a gerrymandered and disjunctive kind, undeserving of the widespread attention it (...) receives in the literature. Instead, metaphilosophers should examine more finely grained mental states. Three promising strategies for parsing intuitions more finely are proposed: by their causal origins, by their context of employment, and by the exoticism of their content. This more narrow focus may significantly alter the dialectic in three prominent metaphilosophical arguments: the argument from calibration, the argument from self-defeat, and the argument from intuitional sensitivity. (shrink)

The paper investigates the epistemological and communicative competences the experts need to use and communicate evidence in the reasoning process leading to diagnosis. The diagnosis and diagnosis communication are presented as intertwined processes that should be jointly addressed in medical consultations, to empower patients’ compliance in illness management. The paper presents defeasible reasoning as specific to the diagnostic praxis, showing how this type of reasoning threatens effective diagnosis communication and entails that we should understand diagnostic evidence as defeasible as well. (...) It argues that metaphors might be effective communicative devices to let the patients understand the relevant defeasors in the diagnostic reasoning process, helping to improve effective diagnosis communication, and also encouraging a change in patients’ beliefs and attitudes on their own experience of illness and illness’ management. (shrink)

In this paper I argue for a capacity account of memory, according to which memory is a neurocognitive capacity to encode, store, and retrieve information. Phenomenal accounts classify memory as having a certain phenomenal character. However, the mental processes generating that phenomenal character are separate from the processes that generate content. Causal accounts require a causal connection between the subject's current representation and their original representation. However, when memory is constructed, this connection does not exist. Unlike its major competitors, the (...) capacity account picks out an epistemically interesting class of memory beliefs while accommodating the constructive nature of memory. (shrink)

But it’s not the mere fact that the RA theorist needs an account of ‘ruling out’ and ‘relevance’ that has tended to lead people to regard the RA approach with suspicion. In itself, this simply means that the RA theorist has some further work to do; and what theorist doesn’t? No; the principal source of scepticism regarding the ability of the RA theorist to come up with a complete and satisfactory account of knowing stems, rather, from an unhappiness with the (...) specific elaborations of the core RA claim that various theorists have offered; for these elaborations have typically involved some rather controversial claims and/or assumptions, and it is against these claims/assumptions that the bulk of the criticism of the whole RA approach has been directed. (shrink)

This paper explores how a certain theory of knowledge—known as anti-luck virtue epistemology—can account for, and in the process shed light on, the notion of an epistemic defeater. To this end, an overview of the motivations for anti-luck virtue epistemology is offered, along with a taxonomy of different kinds of epistemic defeater. It is then shown how anti-luck virtue epistemology can explain: why certain kinds of putative epistemic defeater are not bona fide; how certain kinds of epistemic defeater are genuine (...) in virtue of exposing the subject to significant levels of epistemic risk; and how certain kinds of epistemic defeater are genuine in virtue of highlighting how the subject’s safe cognitive success does not stand in the appropriate explanatory relationship to her manifestation of relevant cognitive ability. (shrink)

In this paper we will analyse the issue of defeasibility in the law, taking into account research carried out in philosophy, artificial intelligence and legal theory. We will adopt a very general idea of legal defeasibility, in which we will include all different ways in which certain legal conclusions may need to be abandoned, though no mistake was made in deriving them. We will argue that defeasibility in the law involves three different aspects, which we will call inference‐based defeasibility, process‐based (...) defeasibility, and theory‐based defeasibility. Only the integration of these three perspectives allows us to provide a satisfactory account of the role of defeasibility in legal reasoning. (shrink)

In a number of recent papers I have been developing the theory of "nomic probability," which is supposed to be the kind of probability involved in statistical laws of nature. One of the main principles of this theory is an acceptance rule explicitly designed to handle the lottery paradox. This paper shows that the rule can also handle the paradox of the preface. The solution proceeds in part by pointing out a surprising connection between the paradox of the preface and (...) the gambler's fallacy. (shrink)

OSCAR is a fully implemented architecture for a cognitive agent, based largely on the author’s work in philosophy concerning epistemology and practical cognition. The seminal idea is that a generally intelligent agent must be able to function in an environment in which it is ignorant of most matters of fact. The architecture incorporates a general-purpose defeasible reasoner, built on top of an efficient natural deduction reasoner for first-order logic. It is based upon a detailed theory about how the various aspects (...) of epistemic and practical cognition should interact, and many of the details are driven by theoretical results concerning defeasible reasoning. The architecture is easily extensible by changing the set of inference schemes supplied to the reasoner. Existing inference schemes handle many kinds of epistemic cognition, including reasoning from perceptual input, causal reasoning and the frame problem, and reasoning defeasibly about probabilities. Work is underway to implement a system of defeasible decisiontheoretic planning. (shrink)

There was a long tradition in philosophy according to which good reasoning had to be deductively valid. However, that tradition began to be questioned in the 1960’s, and is now thoroughly discredited. What caused its downfall was the recognition that many familiar kinds of reasoning are not deductively valid, but clearly confer justification on their conclusions. Here are some simple examples.

In this paper, I examine how the Mode of Infinite Regress functions in Pyrrhonian scepticism. I argue that it is used both to generate an infinite regress of reasons and to show that such infinite regresses are epistemically defective. I clarify precisely how this occurs while examining the Mode’s efficaciousness and whether ancient philosophers might have accepted infinite regresses of reasons. I ultimately argue that they would not for reasons which have hitherto not been adequately appreciated and which shed further (...) light on how the Mode of Infinite Regress functions, its efficacy, and the relevant notions of justification at stake. (shrink)

Efforts to formalize qualitative accounts of inference to the best explanation (IBE) confront two obstacles: the imprecise nature of such accounts and the unusual logical properties that explanations exhibit, such as contradiction-intolerance and irreflexivity. This paper aims to surmount these challenges by utilising a new, more precise theory that treats explanations as expressions that codify defeasible inferences. To formalise this account, we provide a sequent calculus in which IBE serves as an elimination rule for a connective that exhibits many of (...) the properties associated with the behaviour of the English expression ‘That... best explains why ... ’. We first construct a calculus that encodes these properties at the level of the turnstile, i.e. as a metalinguistic expression for classes of defeasible consequence relations. We then show how this calculus can be conservatively extended over a language that contains a best-explains-why operator. (shrink)

While growing empirical evidence suggests a continuity between human and non-human psychology, many philosophers still think that only humans can act and form beliefs rationally. In this paper, we challenge this claim. We first clarify the notion of rationality. We then focus on the rationality of beliefs and argue that, in the relevant sense, humans are not the only rational animals. We do so by first distinguishing between unreflective and reflective responsiveness to epistemic reasons in belief formation and revision. We (...) argue that unreflective responsiveness is clearly within the reach of many animals. We then defend that a key demonstration of reflective responsiveness would be the ability to respond to undermining defeaters. We end by presenting some empirical evidence that suggests that some animal species are capable of processing these defeaters, which would entail that even by the strictest standards, humans are not the only rational animals. (shrink)

widely held commitments: to phenomenal realism and to naturalism. Phenomenal realism is the view that we are phenomenally consciousness, and that there is no a priori or armchair sufficient condition for phenomenal consciousness that can be stated in nonphenomenal terms . 1,2 Block points out that while phenomenal realists reject.

My aim in this paper is to assess the viability of a perceptual epistemology based on what Anil Gupta calls the “hypothetical given”. On this account, experience alone yields no unconditional entitlement to perceptual beliefs. Experience functions instead to establish relations of rational support between what Gupta calls “views” and perceptual beliefs. I argue that the hypothetical given is a genuine alternative to the prevailing theories of perceptual justification but that the account faces a dilemma: on a natural assumption about (...) the epistemic significance of support relations, any perceptual epistemology based on the hypothetical given results in either rationalism or skepticism. I conclude by examining the prospects for avoiding the dilemma. One option is to combine the hypothetical given with a form of holism. Another is to combine the view with a form of hinge epistemology. But neither offers a simple fix. (shrink)

Consider a simple form of process reliabilism: S is justified in believing that p if and only if S’s belief that p was formed through a reliable process. Such accounts are thought to face a counter-example in the form of defeaters. It seems possible that a belief might result from a reliable belief forming process and yet be unjustified because one possesses a defeater with respect to that belief. This counter-example is merely apparent. The problem of defeaters is just a (...) special case of the generality problem, i.e., the problem of determining which of the process types instantiated by a process token is relevant to determining that reliability of the process token. Drawing on similarities between cases that involve defeaters and cases that involve adverse local conditions, e.g., a white-out blizzard, I argue that any adequate solution to the generality problem for all cases that don’t involve defeaters will pick out an unreliable process type as relevant in cases that do involve defeaters. Thus, there is no sui generis problem of defeaters for simple process reliablism. (shrink)

There is much to like about the idea that justification should be understood in terms of normality or normic support (Smith 2016, Goodman and Salow 2018). The view does a nice job explaining why we should think that lottery beliefs differ in justificatory status from mundane perceptual or testimonial beliefs. And it seems to do that in a way that is friendly to a broadly internalist approach to justification. In spite of its attractions, we think that the normic support view (...) faces two serious challenges. The first is that it delivers the wrong result in preface cases. These cases suggest that the view is either too sceptical or too externalist. The second is that the view struggles with certain kinds of Moorean absurdities. It turns out that these problems can easily be avoided. If we think of normality as a condition on *knowledge*, we can characterise justification in terms of its connection to knowledge and thereby avoid the difficulties discussed here. The resulting view does an equally good job explaining why we should think that our perceptual and testimonial beliefs are justified when lottery beliefs cannot be. Thus, it seems that little could be lost and much could be gained by revising the proposal and adopting a view on which it is knowledge, not justification, that depends directly upon normality. (shrink)

Alan Millar's paper involves two parts, which I address in order, first taking up the issues concerning the goal of inquiry, and then the issues surrounding the appeal to reflective knowledge. I argue that the upshot of the considerations Millar raises count in favour of a more important role in value-driven epistemology for the notion of understanding and for the notion of epistemic justification, rather than for the notions of knowledge and reflective knowledge.

When a person has an intuition, it seems to her that things are certain ways; to many it seems that torturing the innocent for fun is wrong, for example. When a person has an intuition, there is also something particular it is like to be her: intuitions have a characteristic phenomenal character. This article asks how the phenomenal character of intuition is related to two core core questions in the philosophy of intuition, namely: Is intuition a source of justification and (...) knowledge? and What are intuitions?. (shrink)

Contemporary memory sciences describe processes that are dynamic and constructive. This has led some philosophers to weaken the relationship between memory and epistemology; though remembering can give rise to epistemic success, it is not itself an epistemic success state. I argue that non-epistemic theories will not do; they provide neither necessary nor sufficient conditions for remembering that p. I also argue that the shortcomings of the causal theory are epistemic in nature. Consequently, a theory of remembering must account for both (...) its fundamentally epistemic nature and for its constructive and dynamic processes. (shrink)

We argue that it is a mistake to approach goodman's new riddle of induction by demarcating projectible from non-Projectible predicates and hypotheses, And put forward an alternative way of looking at the whole question.

This paper argues for two interrelated claims. The first is that the most innovative contribution of Timothy Williamson, Herman Cappelen, and Max Deutsch in the debate about the epistemology of thought experiments is not the denial of intuition and the claim of the irrelevance of experimental philosophy but the claim of epistemological continuity and the rejection of philosophical exceptionalism. The second is that a better way of implementing the claim of epistemological continuity is not Deutsch and Cappelen’s argument view or (...) Williamson’s folk psychological view. This is so because while the argument view makes the basis of the relevant classificational judgement evidentially too demanding; the folk psychological view makes it too weak and error-prone to count as an adequate explanation. Drawing from a certain reading of Aristotle’s Nichomachean Ethics that flowers in Miranda Fricker and John McDowell, I argue for the reason-responsiveness view. Like the extant views, the reason-responsiveness view vindicates the claim of epistemological continuity. But unlike the extant views, it does not share those problematic features. Further, I show that the reason-responsiveness view offers a way for champions of the claim of epistemological continuity to resist Avner Baz’s objection to the claim of epistemological continuity and his objection to the philosophical use of thought experiments while taking on board some attractive elements of his view. (shrink)

This paper introduces and defends the paradigm response to external world skepticism. To understand it, consider an analogy. One of the hallmarks of being a bird is an ability to fly. A penguin lacks this hallmark and thus fails to be a paradigm bird. Likewise, there are various hallmarks of knowledge. Some of your external world beliefs lack some of these hallmarks, and thus fail to be paradigm cases of knowledge. Just as the inability of penguins to fly doesn’t prevent (...) them from being birds, likewise the lack of these hallmarks doesn’t prevent your beliefs from being knowledge. It just prevents them from being paradigm cases thereof. (shrink)

Can it ever be rational to revise one's own logic by one's own lights? In this paper I argue that logic is never rationally revisable, even if one's own logic gives rise to paradoxes and allows one to derive any conclusion whatsoever. Instead of revising logic, we need to revise a certain widely held position in the philosophy of logic, one tied to the standard conception of validity and to the alleged monotonicity of deductive reasoning. I develop the alternative conception (...) of validity and of deductive reasoning, which explains why we are generally entitled to the conclusions of deductive reasoning, even though we rationally do not accept them in certain circumstances tied to paradoxes. (shrink)