For over 20 years, Alvin Plantinga has been advocating his Evolutionary Argument against Naturalism, or EAAN. We will argue that this argument functions as an atypical form of global skepticism, and Plantinga’s development of it has repercussions for other types of skepticism. First, we will go over the similarities and differences; for example, the standard ways of avoiding other forms of skepticism, namely by adopting some form of naturalized or externalist epistemology, do not work with the EAAN. Plantinga himself is (...) a naturalized epistemologist, and his skepticism comes from within this perspective. Next, we will look at how Plantinga moved from presenting his skepticism diachronically, as a loop, to presenting it synchronically, as an infinite regress. Finally, we can extend this move from Plantinga’s skepticism to other forms of global skepticism, in so far as these will involve the rejection of our cognitive faculties’ reliability, and formulate them synchronically as well. Global skepticism is often accused of instability, since it leads us to skepticism about all of our beliefs, including belief in the skeptical scenario itself. Yet formulating it as an infinite regress rather than a loop allows the skeptical charge to go forward. (shrink)

Formal epistemologists often claim that our credences should be representable by a probability function. Complete probabilistic coherence, however, is only possible for ideal agents, raising the question of how this requirement relates to our everyday judgments concerning rationality. One possible answer is that being rational is a contextual matter, that the standards for rationality change along with the situation. Just like who counts as tall changes depending on whether we are considering toddlers or basketball players, perhaps what counts as rational (...) shifts according to whether we are considering ideal agents or creatures more like ourselves. Even though a number of formal epistemologists have endorsed this type of solution, I will argue that there is no way to spell out this contextual account that can make sense of our everyday judgments about rationality. Those who defend probabilistic coherence requirements will need an alternative account of the relationship between real and ideal rationality. (shrink)

Recent views in hinge epistemology rely on doxastic normativism to argue that our attitudes towards hinge propositions are not beliefs. This paper has two aims; the first is positive: it discusses the general normative credentials of this move. The second is negative: it delivers two negative results for No-Belief hinge epistemology such construed. The first concerns the motivation for the view: if we’re right, doxastic normativism offers little in the way of theoretical support for the claim that our attitudes towards (...) hinge propositions are anything but garden-variety beliefs. The second concerns theoretical fruitfulness: we show that embracing a No-Belief view will either get us in serious theoretical trouble, or loose all anti-sceptical appeal. (shrink)

According to many, to have epistemic justification to believe P is just for it to be epistemically permissible to believe P. Others think it is for believing P to be epistemically good. Yet others think it has to do with being epistemically blameless in believing P. All such views of justification encounter problems. Here, a new view of justification is proposed according to which justification is a kind of composite normative status. The result is a view of justification that offers (...) hope of solving some longstanding epistemological problems. (shrink)

Sometimes it’s reasonable to reduce confidence in a proposition in response to gaining etiological information. Suppose, for example, a theist learns that her theism is ‘due to’ her religious upbringing. There is a clear range of cases where it would be reasonable for her to respond by slightly decreasing her confidence in God’s existence. So long as reasonability and justification are distinct, this reasonability claim would appear consistent with the thesis that this kind of etiological information cannot, all by itself, (...) affect one’s justification. In what follows, I argue that this is mistaken. For, even if reasonability and justification are distinct, the reasonability of decreasing confidence in response to etiological information must be explained in terms of a decrease in justification. The argument to follow threatens not only the stronger thesis that etiological information never defeats justification but the substantially weaker thesis, advocated by various authors, that justification is defeated by etiological information in only a limited range of circumstances. I go on to show how the arguments en route to this conclusion have much wider epistemological ramifications. (shrink)

Although it is now commonplace to take emotions to be the sort of phenomena for which there are reasons, the question of how to cash out the reason- responsiveness of emotions remains to a large extent unanswered. I highlight two main ways of thinking about reason-responsiveness, one that takes agential capacities to engage in norm-guided deliberation to underlie reason-responsiveness, and another which instead takes there to be a basic reason-relation between facts and attitudes. I argue that the latter approach should (...) be preferred. Not only does a reasons-basic approach promise to fare better in accounting for cases that its opponent struggles to accommodate, but it promises also to uncover a sui generis relation between emotions and their reasons which is at best obscured and at worst denied by its opponent. (shrink)

According to the Dutch Book Argument (DBA), if an agent's subjective probabilities fail to satisfy the axioms of the probability calculus and so make the agent vulnerable to a Dutch Book, the agent's subjective probabilities are incoherent and the agent is therefore irrational. Critics of DBA have argued, however, that probabilistic incoherence is compatible with various kinds of rationality – logico-semantic, epistemic, instrumental and prudential. In this paper, I provide an interpretation of DBA on which it is true that probabilistic (...) incoherence entails agent irrationality. Articulating this interpretation requires the specification of some of the connections among the varieties of rationality. Once this is done, it becomes possible to vindicate a modest version of DBA. (shrink)

[Significantly updated in Chapter 7 of Awareness and the Substructure of Knowledge] Many have found it plausible that knowledge is a constitutively normative state, i.e. a state that is grounded in the possession of reasons. Many have also found it plausible that certain cases of proprioceptive knowledge, memorial knowledge, and self-evident knowledge are cases of knowledge that are not grounded in the possession of reasons. I refer to these as cases of basic knowledge. The existence of basic knowledge forms a (...) primary objection to the idea that knowledge is a constitutively normative state. In what follows I offer a way through the apparent dilemma of having to choose between either basic knowledge or the normativity of knowledge. The solution involves homing in on a state of awareness (≈non-accidental true representation) that is distinct from knowledge and which in turn grounds the normativity of knowledge in a way that is fully consistent with the existence of basic knowledge. An upshot of this is that externalist theories of knowledge turn out to be fully compatible with the thesis that knowledgeable beliefs are always beliefs that are justified by the reasons one possesses. (shrink)

This paper addresses the meta-epistemological dispute over the basis of epistemic evaluation from the standpoint of meliorative epistemology. Meliorative epistemology aims at guiding our epistemic practice to better results, and it comprises two levels of epistemic evaluation. At the social level (meliorative social epistemology) appropriate experts conduct evaluation for the community, so that epistemic evaluation is externalist since each epistemic subject in the community need not have access to the basis of the experts' evaluation. While at the personal level (meliorative (...) personal epistemology) epistemic evaluation is internalist since each member of the community must evaluate the reliability of the (apparent) experts from the first-person perspective. I argue that evaluation at the social level should be the primary focus of meliorative epistemology since meliorative personal epistemology does not provide informative epistemic norms. It is then pointed out that epistemic evaluation at the social level can be considered internalist in the extended sense (social internalism) in that every component of the evaluation needs to be recognized by some members of the community at some points. As a result, some familiar problems of internalist epistemology, such as regress and circularity of epistemic support, carry over to meliorative social epistemology. (shrink)

This paper defends reductionism about testimonial justification of beliefs against two influential arguments. One is the empirical argument to the effect that the reductionist justification of our trust in testimony is either circular since it relies on testimonial evidence or else there is scarce evidence in support of our trust in testimony. The other is the transcendental argument to the effect that trust in testimony is a prerequisite for the very existence of testimonial evidence since without the presumption of people’s (...) truthfulness we cannot interpret their utterances as testimony with propositional contents. This paper contends that the epistemic subject can interpret utterances as testimony with propositional contents without presupposing the credibility of testimony, and that evidence available to the normal epistemic subject can justify her trust in testimony. (shrink)

Justification logics are a family of modal logics whose non-normal modalities are parametrised by a type-theoretic calculus of terms. The first justification logic was developed by Sergei Artemov to provide an explicit modal logic for arithmetical provability in which these terms were taken to pick out proofs. But, justification logics have been given various other interpretations as well. In this paper, we will rely on an interpretation in which the modality \ is read ‘S accepts \ as justification for \’. (...) Since it is often important to specify just how much confidence agents have in propositions on the basis of justifications, the logic will need to be extended if it is to provide a sufficiently general account. The primary purpose of this paper is to extend justification logic with the expressive resources to needed to do so. Thus, we will construct the justification logic with confidence ). While \ will be extremely general, capable of accommodating a wide range of interpretations, we provide motivation in terms of the notion of confidence deriving recent work by Paul and Quiggin :363–382, 2018). Under this understanding, confidence must only correspond to a partial ordering. We axiomatise \ and provide a sound and complete semantics. (shrink)

Harman and Lewis credit Kripke with having formulated a puzzle that seems to show that knowledge entails dogmatism. The puzzle is widely regarded as having been solved. In this paper we argue that this standard solution, in its various versions, addresses only a limited aspect of the puzzle and holds no promise of fully resolving it. Analyzing this failure and the proper rendering of the puzzle, it is suggested that it poses a significant challenge for the defense of epistemic closure.

According to certain views about human ontology, the way we seem is very different from the way we are. The appearances are a threat to such views. Here I take up and defuse the threat to one such view.Pure immaterialism says that each of us is wholly immaterial. The appearances suggest otherwise. I argue that despite the fact that we might sometimes appear to be at least partly material, and that we can be perceptually justified in believing something solely on (...) the basis of having a perceptual experience as of its being the case, none of us is ever perceptually justified in believing that we are even partly material (or that we’re not). Bottom line: we might be able to know whether we’re material, but we can’t know just by looking. (shrink)

Some philosophers, like David Chalmers, have either shown their sympathy for, or explicitly endorsed, the following two principles: Panpsychism—roughly the thesis that the mind is ubiquitous throughout the universe—and Organizational Invariantism—the principle that holds that two systems with the same fine-grained functional organization will have qualitatively identical experiences. The purpose of this paper is to show the tension between the arguments that back up both principles. This tension should lead, or so I will argue, defenders of one of the principles (...) to give up on the other. (shrink)

In this paper I investigate which of the main conditions proposed in the moral responsibility literature are the ones that spell trouble for the idea that Artificial Intelligence Systems could ever be full-fledged responsible agents. After arguing that the standard construals of the control and epistemic conditions don’t impose any in-principle barrier to AISs being responsible agents, I identify the requirement that responsible agents must be aware of their own actions as the main locus of resistance to attribute that kind (...) of agency to AISs. This is because this type of awareness is thought to involve first-person or de se representations, which, in turn, are usually assumed to involve some form of consciousness. I clarify what this widespread assumption involves and conclude that the possibility of AISs’ moral responsibility hinges on what the correct theory of de se representations ultimately turns out to be. (shrink)

Closure for justification is the claim that thinkers are justified in believing the logical consequences of their justified beliefs, at least when those consequences are competently deduced. Many have found this principle to be very plausible. Even more attractive is the special case of Closure known as Single-Premise Closure. In this paper, I present a challenge to Single-Premise Closure. The challenge is based on the phenomenon of rational self-doubt – it can be rational to be less than fully confident in (...) one's beliefs and patterns of reasoning. In rough outline, the argument is as follows: Consider a thinker who deduces a conclusion from a justified initial premise via an incredibly long sequence of small competent deductions. Surely, such a thinker should suspect that he has made a mistake somewhere. And surely, given this, he should not believe the conclusion of the deduction even though he has a justified belief in the initial premise. (shrink)

The background of this paper (section 1) consists in a new account to foundation‐theoretic epistemology characterized by two features: (i) All beliefs are to be justified by deductive, inductive or abductive inferences from a minimalistic class of unproblematic (introspective or analytic) basic beliefs. (ii) Higher‐order justifications for these inferences are given by means of the novel method of optimality justifications. Optimality justifications are a new tool for epistemology (section 2). An optimality justification does not attempt todemonstratethat a cognitive method is (...) reliable (which is impossible), but pursues the more modest goal of demonstrating that the method isoptimalamong all accessible alternative methods for the given epistemic goal. The reasoning from the established optimality of a method to the acceptability of a particular belief generated by the method is accomplished by so‐called optimality principles. In sections 3–5, the method of optimality justifications is carried out in detail for three fundamental problems: justifying induction, logic, and theory‐generating abduction. (shrink)

In this paper a new conception of foundation-oriented epistemology is developed. The major challenge for foundation-oriented justifications consists in the problem of stopping the justificational regress without taking recourse to dogmatic assumptions or circular reasoning. Two alternative accounts that attempt to circumvent this problem, coherentism and externalism, are critically discussed and rejected as unsatisfactory. It is argued that optimality arguments are a new type of foundation-oriented justification that can stop the justificational regress. This is demonstrated on the basis of a (...) novel result in the area of induction: the optimality of meta-induction. In the final section the method of optimality justification is generalized to deductive and abductive inferences. (shrink)

According to memory foundationalism, seeming to remember that P is prima facie justification for believing that P. There is a common objection to this theory: If I previously believed that P carelessly (i.e. without justification) and later seem to remember that P, then (according to memory foundationalism) I have somehow acquired justification for a previously unjustified belief. In this paper, I explore this objection. I begin by distinguishing between two versions of it: One where I seem to remember that P (...) while also seeming to remember being careless in my original believing that P and the other where I seem to remember that P while not seeming to remember my past carelessness. I argue that the former case is the real challenge for memory foundationalism. After establishing the case of unforgotten carelessness as objection to memory foundationalism, I recast memory foundationalism in way that allows it to escape this objection. (shrink)

There are many domains about which we think we are reliable. When there is prima facie reason to believe that there is no satisfying explanation of our reliability about a domain given our background views about the world, this generates a challenge to our reliability about the domain or to our background views. This is what is often called the reliability challenge for the domain. In previous work, I discussed the reliability challenges for logic and for deductive inference. I argued (...) for four main claims: First, there are reliability challenges for logic and for deduction. Second, these reliability challenges cannot be answered merely by providing an explanation of how it is that we have the logical beliefs and employ the deductive rules that we do. Third, we can explain our reliability about logic by appealing to our reliability about deduction. Fourth, there is a good prospect for providing an evolutionary explanation of the reliability of our deductive reasoning. In recent years, a number of arguments have appeared in the literature that can be applied against one or more of these four theses. In this paper, I respond to some of these arguments. In particular, I discuss arguments by Paul Horwich, Jack Woods, Dan Baras, Justin Clarke-Doane, and Hartry Field. (shrink)

In the following I discuss the debate between epistemological internalists and externalists from an unfamiliar meta-epistemological perspective. In doing so, I focus on the question of whether rationality is best captured in externalist or internalist terms. Using a conception of epistemic judgments as “doxastic plans,” I characterize one important subspecies of judgments about epistemic rationality—focusing on the distinctive rational/functional role these judgments play in regulating how we form beliefs. Then I show why any judgment that plays this role should be (...) expected to behave the manner internalists predict. In this way, I argue, we can explain why our basic toolbox for epistemic evaluation includes an internalist conception of rationality. (shrink)

According to the standard view, a belief is based on a reason and doxastically justified—i.e., permissibly held—only if a causal relation obtains between a reason and the belief. In this paper, I argue that a belief can be doxastically justified by a reason’s mere disposition to sustain it. Such a disposition, however, wouldn’t establish a causal connection unless it were manifested. My argument is that, in the cases I have in mind, the manifestation of this disposition would add no positive (...) epistemic feature to the belief: a belief that is justified after the manifestation of a reason’s causal powers must have already been justified before their manifestation. As a result, those who adhere to the standard causal view of the basing relation face a hard choice: they should either abandon the enormously popular view that doxastic justification has a basing requirement or modify their view of the basing relation. (shrink)

Logic ought to guide our thinking. It is better, more rational, more intelligent to think logically than to think illogically. Illogical thought leads to bad judgment and error. In any case, if logic had no role to play as a guide to thought, why should we bother with it?The somewhat naïve opinions of the previous paragraph are subject to attack from many sides. It may be objected that an activity does not count as thinking at all unless it is at (...) least minimally logical, so logic is constitutive of thought rather than a guide to it. Or it may be objected that whereas logic describes a system of timeless relations between propositions, thinking is a dynamic process involving revisions, and so could not use a merely static guide. Or again the objection may be that there is no such thing as logic, only a whole variety of different logics, not all of which could possibly be good guides. (shrink)

In his Epistemic Justification , Swinburne offers a sophisticated and intuitively plausible causal-doxastic analysis of the basing relation that has escaped the attention of those working on this relation, where the basing relation can be understood as the relation that holds between a reason and one’s belief when the belief is held for that reason. In this paper, I aim to fill this lacuna in the literature by arguing that, despite its initial plausibility, Swinburne’s analysis of the basing relation is (...) subject to a simple counterexample and so must be rejected. (shrink)

Sometimes we get what seem to be good reasons for believing that we’ve misevaluated our evidence for a proposition P. In those cases, can we use our evidence for P itself to show that we haven’t misevaluated our evidence for P? I show why doing so appears to employ viciously circular reasoning. However, I then argue that this appearance is illusory in certain cases and that we sometimes can legitimately reason in that way. This claim sheds new light on the (...) nature of epistemic undermining and epistemic circularity. In addition, it has implications for the current debate about the epistemic significance of disagreement. An important and influential position in that debate says that disagreement with others dramatically undermines our justification for a wide range of our opinions (e.g., political, religious, moral, economic, and philosophical opinions). My view on undermining and circularity implies that this position on disagreement rests on a mistake. (shrink)

In this paper, we offer an alternative interpretation for the claim that ‘S is justified in believing that φ’. First, we present what seems to be a common way of interpreting this claim: as an attribution of propositional justification. According to this interpretation, being justified is just a matter of having confirming evidence. We present a type of case that does not fit well with the standard concept, where considerations about cognition are made relevant. The concept of cognitive algorithm is (...) presented and explained. Finally, the new reading of ‘S is justified in believing that φ’ is fleshed out. According to this interpretation, being justified in believing that φ is not just a matter of having evidence in favor of φ, but also of having a cognitive algorithm available such that it allows one to form belief in φ on the basis of the relevant evidence. (shrink)

In this paper, I flesh out an account of the inferential basing relation using a theory about how humans reason: the mental models theory. I critically assess some of the notions that are used by that theory to account for inferential phenomena. To the extent that the mental models theory is well confirmed, that account of basing would be motivated on empirical grounds. This work illustrates how epistemologists could offer explications of the basing relation which are more detailed and less (...) empirically risky. (shrink)

Christian apologists argue that the testimony of the miracles of Jesus provide evidence for Christianity. Hume tries to undermine this argument by pointing out that miracles are said to occur in other religious traditions and so miracles do not give us reason to believe in Christianity over the alternatives. Thus, competing miracles act as an undercutting defeater for the argument from miracles for Christianity. Yet, before Hume, Locke responds to this kind of objection, and in this paper I explain and (...) defend his response. In short, Locke argues that God will ensure that there is more evidence for Christianity (if true) and this greater evidence is an undercutting defeater for Hume’s competing miracles defeater (i.e., it is a defeater-defeater). If so, then, as Locke argues, competing miracles do not weaken the evidence from miracles for Christianity. (shrink)

Something about this argument sounds funny. As we’ll see, though, it takes some care to identify exactly what Moore has done wrong. Iwill assume that Moore knows premise (2) to be true. One could inquire into how he knows it, and whether that knowledge can be defeated; but Iwon’t. I’ll focus instead on what epistemic relations Moore has to premise (1) and to his conclusion (3). It may matter which epistemic relations we choose to consider. Some philosophers will diagnose Moore’s (...) argument using Contextualist machinery. They’ll say. (shrink)

A certain interpretation of Wittgenstein’s remarks in On Certaintyadvanced by such figures as Hilary Putnam, Peter Strawson, Avrum Stroll and Crispin Wrighthas become common currency in the recent literature. In particular, this reading focuses upon the supposed anti-sceptical import of the Wittgensteinian notion of a “hinge” proposition. In this paper it is argued that this interpretation is flawed both on the grounds that there is insufficient textual support for this reading and that, in any case, it leads to unpalatable philosophical (...) problems. Moreover, it is claimed that the popularity of this construal of On Certainty in the contemporary debate reflects an implicit commitment to the contentious doctrine of epistemological internalism. Nevertheless, it is argued that, suitably modified along the epistemologically externalist lines suggested by Michael Williams, one might be able to resurrect a viable anti-sceptical hinge proposition thesis. Furthermore, it is claimed that such a conception of the notion also receives some, albeit inconclusive, textual support from On Certainty. (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)

I argue that if there are nondisabled reasons to believe p, then there cannot be nondisabled reasons to believe something incompatible with p. I first defend a restricted version of the view, which applies only to situations where the relevant agent has complete evidence. Then, I argue for a generalized version of the view, which holds regardless of the agent's evidence. As a related result, I show that, given plausible assumptions, there cannot be nondisabled reasons to believe something false.

I argue that if there are nondisabled reasons to believe p, then there cannot be nondisabled reasons to believe something incompatible with p. I first defend a restricted version of the view, which applies only to situations where the relevant agent has complete evidence. Then, I argue for a generalized version of the view, which holds regardless of the agent's evidence. As a related result, I show that, given plausible assumptions, there cannot be nondisabled reasons to believe something false.

Epistemic conservatism is the thesis that the mere holding of a belief confers some positive epistemic status on its content. Conservatism is widely criticized on the grounds that it conflicts with the main goal in epistemology to believe truths and disbelieve falsehoods. In this paper I argue for conservatism and defend it from objections. First, I argue that the objection to conservatism from the truth goal in epistemology fails. Second, I develop and defend an argument for conservatism from the perspectival (...) character of the truth goal. Finally, I examine several forceful challenges to conservatism and argue that these challenges are unsuccessful. The first challenge is that conservatism implies the propriety of assertions like ‘I believe p and this is part of my justification for it’. The second challenge argues that conservatism wrongly implies that the identity of an epistemic agent is relevant to the main goal of believing truths and disbelieving falsehoods. The last two challenges I consider are the ‘extra boost’ objection and the conversion objection. Each of these objections helps to clarify the nature of the conservative thesis. The upshot of the paper is that conservatism is an important and viable epistemological thesis. (shrink)

Imagine yourself sitting on your front porch, sipping your morning coffee and admiring the scene before you. You see trees, houses, people, automobiles; you see a cat running across the road, and a bee buzzing among the flowers. You see that the flowers are yellow, and blowing in the wind. You see that the people are moving about, many of them on bicycles. You see that the houses are painted different colors, mostly earth tones, and most are one-story but a (...) few are two-story. It is a beautiful morning. Thus the world interfaces with your mind through your senses. There is a strong intuition that we are not disconnected from the world. We and the other things we see around us are part of a continuous whole, and we have direct access to them through vision, touch, etc. However, the philosophical tradition tries to drive a wedge between us and the world by insisting that the information we get from perception is the result of inference from indirect evidence that is about how things look and feel to us. The philosophical problem of perception is then to explain what justifies these inferences. We will focus on visual perception. Figure one presents a crude diagram of the cognitive system of an agent capable of forming beliefs on the basis of visual perception. Cognition begins with the stimulation of the rods and cones on the retina. From that physical input, some kind of visual processing produces an introspectible visual image. In response to the production of the visual image, the cognizer forms beliefs about his or her surroundings. Some beliefs the perceptual beliefs are formed as direct responses to the visual input, and other beliefs are inferred from the perceptual beliefs. The perceptual beliefs are, at the very least, caused or causally influenced by having the image. This is signified by the dashed arrow marked with a large question mark. We will refer to this as the mystery link. Figure one makes it apparent that in order to fully understand how knowledge is based on perception, we need three different theories.. (shrink)

The author poses a question: when a person has a thought, what is it that determines what thought he is having? and, equivalently, what is it that determines what thought he is having. looking for an answer he sketches some general aspects of the problems involved in answering these questions, like the mind/body problem, for example. his conclusion is that the posed questions should be set against the background assumption that thoughts are just internal physical occurrences, and that thoughts are (...) categorized in the same way other mental occurrences are categorized. so the author categorizes them in terms of their introspectible characteristics and in terms of "that" clauses. these classifications can be understood as describing thought in terms of their place in the rational architecture. (shrink)

This article sketches a theory of objective probability focusing on nomic probability, which is supposed to be the kind of probability figuring in statistical laws of nature. The theory is based upon a strengthened probability calculus and some epistemological principles that formulate a precise version of the statistical syllogism. It is shown that from this rather minimal basis it is possible to derive theorems comprising (1) a theory of direct inference, and (2) a theory of induction. The theory of induction (...) is not of the familiar Bayesian variety, but consists of a precise version of the traditional Nicod Principle and its statistical analogues. (shrink)

A rational agent has beliefs reflecting the state of its environment, and likes or dislikes Its situation. When it finds the world not entirely to Its liking, it tries to change that. We can, accordingly, evaluate a system of cognition in terms of its probable success in bringing about situations that are to the agent's liking. In doing this we are viewing practical reasoning from “the design stance.” It is argued that a considerable amount of the structure of rationality can (...) be elicited as providing the only apporant solutions to various logical and feasibility problems that arise in the course of trying to design a rational agent that satisfies this design specification. (shrink)

To summarize, in order for rational agents to be able to engage in the sophisticated kinds of reasoning exemplified by human beings, they must be able to introspect much of their cognition. The problem of other minds and the problem of knowing the mental states of others will arise automatically for any rational agent that is able to introspect its own cognition. The most that a rational agent can reasonably believe about other rational agents is that they have rational architectures (...) similar to its own, and that they have thoughts related to their rational architectures in certain ways. This leads to Rational Functionalism as an account of what it is to be a cognizer having mental states. That in turn entails that a computer can be a person in precisely the same sense as my next door neighbor if it can appropriately mimic my rational architecture. There is nothing I could know about my neighbor that I could not believe with equal justification about the computer. Rational Functionalism also makes it reasonable to define the narrow content of a thought to be its overall place in the agent's rational architecture, that is, its conceptual role. This is, however, avery narrow notion of content. For practical purposes, we are not interested in knowing the narrow contents of other people's thoughts. We are only interested in rather general properties of those narrow contents. This is what is expressed by the use ofthat-clauses in public language. (shrink)

Counterexamples are constructed for the theory of rational choice that results from a direct application of classical decision theory to ordinary actions. These counterexamples turn on the fact that an agent may be unable to perform an action, and may even be unable to try to perform an action. An alternative theory of rational choice is proposed that evaluates actions using a more complex measure, and then it is shown that this is equivalent to applying classical decision theory to "conditional (...) policies" rather than ordinary actions. (shrink)

A theory of rational choice is a theory of how an agent should, rationally, go about deciding what actions to perform at any given time. For example, I may want to decide whether to go to a movie this evening or stay home and read a book. The actions between which we want to choose are perfectly ordinary actions, and the presumption is that to make such a decision we should attend to the likely consequences of our decision. It is (...) assumed that these decisions must be made in the face of uncertainty regarding both the agent’s initial situation and the consequences of his actions. (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)

Practical reasoning aims at deciding what actions to perform in light of the goals a rational agent possesses. This has been a topic of interest in both philosophy and artificial intelligence, but these two disciplines have produced very different models of practical reasoning. The purpose of this paper is to examine each model in light of the other and produce a unified model adequate for the purposes of both disciplines and superior to the standard models employed by either.The philosophical (decision-theoretic) (...) model directs activity by evaluating acts one at a time in terms of their expected utilities. It is argued that, except in certain special cases, this constitutes an inadequate theory of practical reasoning leading to intuitively incorrect action prescriptions. Acts must be viewed as parts of plans, and plans evaluated as coherent units rather than piecemenal in terms of the acts comprising them. Rationality dictates choosing acts by first choosing the plans prescribing them. Plans, in turn, are compared by looking at their expected values. However, because plans can be embedded in one another, we cannot select plans just by maximizing expected values. Instead, we must employ a more complex criterion here named coextendability. (shrink)

How much linguistic understanding is required for testimonial knowledge acquisition? One answer is that, so long as we grasp the content expressed by the speaker, it does not matter if our understanding of it is poor. Call this the ‘Liberal View’ of testimony. This approach looks especially promising when combined with the thesis that we share a public language that makes it easy to grasp the right content. In this paper, I argue that this picture is epistemically problematic. Poor linguistic (...) understanding undermines our ability to recognise evidence and counterevidence for the testimonial content. Because of this, in many cases in which a hearer’s understanding is poor, her resultant testimonial belief will lack sufficient warrant to qualify as knowledge. Given that we often do not possess a sufficiently good understanding of the testimony we consume, I argue that we acquire far less knowledge through testimony than the Liberal View suggests. (shrink)