Rationality Through Reasoning answers the question of how people are motivated to do what they believe they ought to do, built on a comprehensive account of normativity, rationality and reasoning that differs significantly from much existing philosophical thinking. Develops an original account of normativity, rationality and reasoning significantly different from the majority of existing philosophical thought Includes an account of theoretical and practical reasoning that explains how reasoning is something we ourselves do, rather than something that happens in us Gives (...) an account of what reasons are and argues that the connection between rationality and reasons is much less close than many philosophers have thought Contains rigorous new accounts of oughts including owned oughts, agent-relative reasons, the logic of requirements, instrumental rationality, the role of normativity in reasoning, following a rule, the correctness of reasoning, the connections between intentions and beliefs, and much else. Offers a new answer to the ‘motivation question’ of how a normative belief motivates an action. (shrink)

Brian Hedden defends a radical view about the relationship between rationality, personal identity, and time. On the standard view, personal identity over time plays a central role in thinking about rationality, because there are rational norms for how a person's attitudes and actions at one time should fit with her attitudes and actions at other times. But these norms are problematic. They make what you rationally ought to believe or do depend on facts about your past that aren't part of (...) your current perspective on the world, and they make rationality depend on controversial, murky metaphysical facts about what binds different instantaneous snapshots into a single person extended in time. Hedden takes a different approach, treating the relationship between different time-slices of the same person as no different from the relationship between different people. On his account, the locus of rationality is the time-slice rather than the temporally extended agent. This impersonal, time-slice-centric approach to rationality yields a unified approach to the rationality of beliefs, preferences, and actions where what rationality demands of you is solely determined by your evidence, with no special weight given to your past beliefs or actions. (shrink)

Some philosophers have recently argued that there are no diachronic norms of epistemic rationality, that is, that there are no norms regarding how you should change your attitudes over time. I argue that this is wrong on the grounds that there are norms governing reasoning.

Mark Jago presents an original philosophical account of meaningful thought: in particular, how it is meaningful to think about things that are impossible. We think about impossible things all the time. We can think about alchemists trying to turn base metal to gold, and about unfortunate mathematicians trying to square the circle. We may ponder whether God exists; and philosophers frequently debate whether properties, numbers, sets, moral and aesthetic qualities, and qualia exist. In many philosophical or mathematical debates, when one (...) side of the argument gets things wrong, it necessarily gets them wrong. As we consider both sides of one of these philosophical arguments, we will at some point think about something that’s impossible. Yet most philosophical accounts of meaning and content hold that we can’t meaningfully think or reason about the impossible. -/- In The Impossible, Jago argues that we often gain new information, new beliefs, and, sometimes, fresh knowledge through logic, mathematics, and philosophy. That is why logic, mathematics, and philosophy are useful. We therefore require accounts of knowledge and belief, of information and content, and of meaning which allow space for the impossible. Jago’s aim in this book is to provide such accounts. He gives a detailed analysis of the concept of hyperintensionality, whereby logically equivalent contents may be distinct, and develops a theory in terms of possible and impossible worlds. Along the way, he provides a theory of what those worlds are and how they feature in our analysis of normative epistemic concepts: knowledge, belief, information, and content. (shrink)

I advocate Time-Slice Rationality, the thesis that the relationship between two time-slices of the same person is not importantly different, for purposes of rational evaluation, from the relationship between time-slices of distinct persons. The locus of rationality, so to speak, is the time-slice rather than the temporally extended agent. This claim is motivated by consideration of puzzle cases for personal identity over time and by a very moderate form of internalism about rationality. Time-Slice Rationality conflicts with two proposed principles of (...) rationality, Conditionalization and Reflection. Conditionalization is a diachronic norm saying how your current degrees of belief should fit with your old ones, while Reflection is a norm enjoining you to defer to the degrees of belief that you expect to have in the future. But they are independently problematic and should be replaced by improved, time-slice-centric principles. Conditionalization should be replaced by a synchronic norm saying what degrees of belief you ought to have given your current evidence and Reflection should be replaced by a norm which instructs you to defer to the degrees of belief of agents you take to be experts. These replacement principles do all the work that the old principles were supposed to do while avoiding their problems. In this way, Time-Slice Rationality puts the theory of rationality on firmer foundations and yields better norms than alternative, non-time-slice-centric approaches. (shrink)

In some previous work, I tried to give a concept-based account of the nature of our entitlement to certain very basic inferences (see the papers in Part III of Boghossian 2008b). In this previous work, I took it for granted, along with many other philosophers, that we understood well enough what it is for a person to infer. In this paper, I turn to thinking about the nature of inference itself. This topic is of great interest in its own right (...) and surprisingly understudied by philosophers. A correct understanding of inference promises to shed light on a number of important topics. In particular, it threatens to undermine the sort of concept-based story about entitlement to which I had previously been attracted. (shrink)

Regress arguments have convinced many that reasoning cannot require beliefs about what follows from what. In this paper I argue that this is a mistake. Regress arguments rest on dubious (although deeply entrenched) assumptions about the nature of reasoning — most prominently, the assumption that believing p by reasoning is simply a matter of having a belief in p with the right causal ancestry. I propose an alternative account, according to which beliefs about what follows from what play a constitutive (...) role in reasoning. (shrink)

I argue against the orthodox view of the relationship between propositional and doxastic justification. The view under criticism is: if p is propositionally justified for S in virtue of S's having reason R, and S believes p on the basis of R, then S's belief that p is doxastically justified. I then propose and evaluate alternative accounts of the relationship between propositional and doxastic justification, and conclude that we should explain propositional justification in terms of doxastic justification. If correct, this (...) proposal would constitute a significant advance in our understanding of the sources of epistemic justification. (shrink)

What exactly is reasoning? Like many other philosophers, I shall endorse a broadly causal conception of reasoning. Reasoning is a causal process, in which one mental event (say, one’s accepting the conclusion of a certain argument) is caused by an antecedent mental event (say, one’s considering the premises of the argument). Just like causal accounts of action and causal accounts of perception, causal accounts of reasoning have to confront a version of what has come to be known as the problem (...) of deviant causal chains. In this paper, I shall propose an account of the nature of reasoning, incorporating a solution to the specific version of the deviant causal chains problem that arises for accounts of reasoning. One striking feature of my solution is that it requires that certain normative facts are causally efficacious. It might be thought that this feature will make my account incompatible with any plausibly naturalistic approach to understanding the mind. I shall argue that this is not so: my account of the nature of reasoning is quite compatible with plausible versions of naturalism. (shrink)

What would something unlike us--a chimpanzee, say, or a computer--have to be able to do to qualify as a possible knower, like us? To answer this question at the very heart of our sense of ourselves, philosophers have long focused on intentionality and have looked to language as a key to this condition. Making It Explicit is an investigation into the nature of language--the social practices that distinguish us as rational, logical creatures--that revises the very terms of this inquiry. Where (...) accounts of the relation between language and mind have traditionally rested on the concept of representation, this book sets out an alternate approach based on inference, and on a conception of certain kinds of implicit assessment that become explicit in language. Making It Explicit is the first attempt to work out in detail a theory that renders linguistic meaning in terms of use--in short, to explain how semantic content can be conferred on expressions and attitudes that are suitably caught up in social practices. -/- At the center of this enterprise is a notion of discursive commitment. Being able to talk--and so in the fullest sense being able to think--is a matter of mastering the practices that govern such commitments, being able to keep track of one’s own commitments and those of others. Assessing the pragmatic significance of speech acts is a matter of explaining the explicit in terms of the implicit. As he traces the inferential structure of the social practices within which things can be made conceptually explicit, the author defines the distinctively expressive role of logical vocabulary. This expressive account of language, mind, and logic is, finally, an account of who we are. (shrink)

The philosophical literature on reasoning is dominated by the assumption that reasoning is essentially a matter of following rules. This paper challenges this view, by arguing that it misrepresents the nature of reasoning as a personal level activity. Reasoning must reflect the reasoner’s take on her evidence. The rule-following model seems ill-suited to accommodate this fact. Accordingly, this paper suggests replacing the rule-following model with a different, semantic approach to reasoning.

John Gibbons presents an original account of epistemic normativity. Belief seems to come with a built-in set of standards or norms. One task is to say where these standards come from. But the more basic task is to say what those standards are. In some sense, beliefs are supposed to be true. Perhaps they’re supposed to constitute knowledge. And in some sense, they really ought to be reasonable. Which, if any of these is the fundamental norm of belief? The book (...) argues against the teleological or instrumentalist conception of rationality that sees being reasonable as a means to our more objective aims, either knowledge or truth. And it tries to explain both the norms of knowledge and of truth in terms of the fundamental norm, the one that tells you to be reasonable. The importance of being reasonable is not explained in terms of what it will get you, or what you think it will get you, or what it would get you if only things were different. The requirement to be reasonable comes from the very idea of what a genuine requirement is. That’s where the built-in standards governing belief come from, and that’s what they are. (shrink)

Some philosophers think that rationality consists in responding correctly to reasons, or alternatively in responding correctly to beliefs about reasons. This paper considers various possible interpretations of ‘responding correctly to reasons’ and of ‘responding correctly to beliefs about reasons’, and concludes that rationality consists in neither, under any interpretation. It recognizes that, under some interpretations, rationality does entail responding correctly to beliefs about reasons. That is: necessarily, if you are rational you respond correctly to your beliefs about reasons.

An attempt to analyse what it is for belief to be based on reasons becomes involved with questions about the goodness of reasons and the gettier examples. intuitions about knowledge and the "gettier effect" can be used to decide when reasoning has occurred and what reasoning there has been. explanation by reasons is not deterministic.

Reasoning is an activity of ours by which we come to satisfy synchronic requirements of rationality. However, reasoning itself is regulated by diachronic permissions of rationality. For each synchronic requirement there appears to be a corresponding diachronic permission, but the requirements and permissions are not related to each other in a systematic way. It is therefore a puzzle how reasoning according to permissions can systematically bring us to satisfy requirements.

Ichikawa and Jarvis offer a new rationalist theory of mental content and defend a traditional epistemology of philosophy. They argue that philosophical inquiry is continuous with non-philosophical inquiry, and can be genuinely a priori, and that intuitions do not play an important role in mental content or the a priori.

The paper asks under what conditions deductive reasoning transmits justification from its premises to its conclusion. It argues that both standard externalist and standard internalist accounts of this phenomenon fail. The nature of this failure is taken to indicate the way forward: basic forms of deductive reasoning must justify by being instances of 'blind but blameless' reasoning. Finally, the paper explores the suggestion that an inferentialist account of the logical constants can help explain how such reasoning is possible.

Classical logic has been attacked by adherents of rival, anti-realist logical systems: Ian Rumfitt comes to its defence. He considers the nature of logic, and how to arbitrate between different logics. He argues that classical logic may dispense with the principle of bivalence, and may thus be liberated from the dead hand of classical semantics.

It has been a commonplace from the beginnings of philosophical thought that what distinguishes humans from other species is the ability to reason; reason- ing is held to be an essential characteristic of the species and one that is unique to it. The essence condition requires that all humans possess at least the capacity for reasoning and that it be exercised in many of the ordinary cases of acquiring beliefs. And uniqueness entails that non-humans cannot reason, no matter how much (...) their behavior resembles that of humans. I think that a certain specific model of reasoning has been presupposed by proponents of these claims. And there are grounds to believe that this model is inaccurate in essential respects: if reasoning does correspond to it, then few human beliefs are acquired through reason. However, given a more accurate description of what goes on in normal human reasoning, it is no longer plausible to think that only humans reason. So either the essence or the uniqueness claim must be given up. In this paper I argue for the second option. (shrink)

The standard paradigm for mental causation is a person’s acting for a reason. Something happens - she intentionally φ’s - the occurrence of which we explain by citing a relevant belief or desire. In the present context, I simply take for granted the following two conditions on the appropriateness of this explanation. First, the agent φ’s _because_ she believes/desires what we say she does, where this is expressive of a _causal_ dependence.1 Second, her believing/desiring this gives her a _reason_ for (...) φ-ing: recognizing that she has this belief/desire makes her φ-ing intelligible as rational in the light of her other attitudes and circumstances. A further condition must be met, though, if this is to be a genuine psychological explanation, a case of her acting _for_ the reason in question. Consider the following example of Davidson’s (1973, p. 79). An exhausted climber is desperate to rid herself of the weight and danger of holding her partner on a rope; and her sudden realization that simply letting go would achieve this so unnerves her that her grip loosens slightly and he falls. Her releasing him causally depends upon her having this belief and desire, which provide _a_ reason for doing what she does. But this is not _why_ she does it: it would be at best misleading to say that she dropped him, intentionally, because she was fed up with holding his weight, or because she thought that she might otherwise fall. Her letting go does not depend upon her having these reasons in the right way. The reason-giving relation is causally irrelevant. If we are to explain a person’s acting _for_ a reason, then her doing. (shrink)

There is a problem with a very common theory of the nature of action. The problem stems from the fact that causation by practical reasons may be a necessary condition for being an intentional action, but it can’t be a sufficient condition. After all, desires and intentions are caused by practical reasons that rationalize them, but they’re clearly not actions. Even if all actions are events or changes and desires and intentions aren’t, the acquistion of a desire or an intention (...) is an event, but it isn’t always an action. If we can’t understand the nature of action in terms of causation by practical reasons, how should we understand it? The problem only arises if you believe that causation by practical reasons is not sufficient. Maybe the kinds of reasons that rationalize actions are different from the kinds of reasons that rationalize desires and intentions. It’s natural to suppose that reasons for A-ing have to be about A-ing. If the mental state that causes you to turn on the light counts as a reason for turning on the light, then the notion of turning on the light has to figure in the content of the cause. You might believe that turning on the light is a means to an end. Or you might just want to turn on the light. If reasons for A-ing are always about A-ing, but reasons for desiring or intending are only about the objects of desire or intention, if they’re first-order rather than secondorder, then maybe the kinds of reasons that rationalize actions are different from the kinds of.. (shrink)

This chapter defines and defends time-slice epistemology, according to which there are no essentially diachronic norms of rationality. The chapter begins by distinguishing two notions of time-slice epistemology, and ends by defending time-slice theories of action under indeterminacy, i.e. theories about how you should act when the outcome of your decision depends on some indeterminate claim. In a recent chapter, J. Robert G. Williams defends a theory of action under indeterminacy which is subject to several objections. An alternative theory is (...) proposed in its place. The resulting discussion highlights a more general moral about action under indeterminacy, namely that time-slice theories are supported by strong analogies with ethical theories. In particular, our understanding of agents torn between interpretations of a decision situation should be guided by our theories of agents torn between incommensurable values. (shrink)