The paper argues that, although a distinction between a priori and a posteriori knowledge (or justification) can be drawn, it is a superficial one, of little theoretical significance. The point is not that the distinction has borderline cases, for virtually all useful distinctions have such cases. Rather, it is argued by means of an example, the differences even between a clear case of a priori knowledge and a clear case of a posteriori knowledge may be superficial ones. In both cases, (...) experience plays a role that is more than purely enabling but less than strictly evidential. It is also argued that the cases at issue are not special, but typical of a wide range of others, including knowledge of axioms of set theory and of elementary logical truths. Attempts by Quine and others to make all knowledge a posteriori (‘empirical’) are repudiated. The paper ends with a call for a new framework to be developed for analysing the epistemology of cognitive uses of the imagination. (shrink)
The Linguistic Turn is the title of an influential anthology edited by Richard Rorty, published in 1967. In his introduction, Rorty explained: The purpose of the present volume is to provide materials for reflection on the most recent philosophical revolution, that of linguistic philosophy. I shall mean by “linguistic philosophy” the view that philosophical problems are problems which may be solved (or dissolved) either by reforming language, or by understanding more about the language we presently use. (1967: 3) ‘The linguistic (...) turn’ has subsequently become a standard vague phrase for a diffuse event — some regard it as the event — in twentieth century philosophy, one not confined to signed-up linguistic philosophers in Rorty’s sense. For those who took the turn, language was somehow the central theme of philosophy. There is an increasingly widespread sense that the linguistic turn is past. In this essay I ask how far the turn has been, or should be, reversed. (shrink)
1. As John Hawthorne and Maria Lasonen-Aarnio appreciate, some of the central issues raised in their ‘Knowledge and Objective Chance’ arise for all but the most extreme theories of knowledge. In a wide range of cases, according to very plausible everyday judgments, we know something about the future, even though, according to quantum mechanics, our belief has a small but nonzero chance (objective probability) of being untrue. In easily constructed examples, we are in that position simultaneously with respect to many (...) different propositions about the future that are equiprobable and probabilistically independent of each other, at least to a reasonable approximation. (shrink)
Some systems of modal logic, such as S5, which are often used as epistemic logics with the ‘necessity’ operator read as ‘the agent knows that’, are problematic as general epistemic logics for agents whose computational capacity does not exceed that of a Turing machine because they impose unwarranted constraints on the agent’s theory of non-epistemic aspects of the world, for example by requiring the theory to be decidable rather than merely recursively axiomatizable. To generalize this idea, two constraints on an (...) epistemic logic are formulated: r.e. conservativeness, that any recursively enumerable theory R in the sublanguage without the epistemic operator is conservatively extended by some recursively enumerable theory in the language with the epistemic operator which is permitted by the logic to be the agent’s overall theory; the weaker requirement of r.e. quasi-conservativeness is similar except for applying only when R is consistent. The logic S5 is not even r.e. quasiconservative; this result is generalized to many other modal logics. However, it is also proved that the modal logics S4, Grz and KDE are r.e. quasi-conservative and that K4, KE and the provability logic GLS are r.e. conservative. Finally, r.e. conservativeness and r.e. quasiconservativeness are compared with related non-computational constraints. (shrink)
Audi explains what he means by ‘normative’ in the case of belief: cognitive (epistemic) normativity is a matter of what ought to be believed, where the force of the “ought” is in part to attribute liability to criticism and negative (disapproving) attitudes toward the person(s) in question.
Second-order logic and modal logic are both, separately, major topics of philosophical discussion. Although both have been criticized by Quine and others, increasingly many philosophers find their strictures uncompelling, and regard both branches of logic as valuable resources for the articulation and investigation of significant issues in logical metaphysics and elsewhere. One might therefore expect some combination of the two sorts of logic to constitute a natural and more comprehensive background logic for metaphysics. So it is somewhat surprising to find (...) that philosophical discussion of secondorder modal logic is almost totally absent, despite the pioneering contribution of Barcan.. (shrink)
The paper is a critique of the widespread conception of logic as a neutral arbiter between metaphysical theories, one that makes no `substantive’ claims of its own (David Kaplan and John Etchemendy are two recent examples). A familiar observation is that virtually every putatively fundamental principle of logic has been challenged over the last century on broadly metaphysical grounds (however mistaken), with a consequent proliferation of alternative logics. However, this apparent contentiousness of logic is often treated as though it were (...) neutralized by the possibility of studying all these alternative logics within an agreed metalogical framework, typically that of first-order logic with set theory. In effect, metalogic is given the role of neutral arbiter. The paper will consider a variety of examples in which deep logical disputes re-emerge at the meta-level. One case is quantified modal logic, where some varieties of actualism require a modal meta-language (as opposed to the usual non-modal language of possible worlds model theory) in order not to make their denial of the Barcan formula self-defeating. Similarly, on some views the intended model theory for second-order logic can only be given in a second-order metalanguage—this may be needed to avoid versions of Russell’s paradox when the first-order quantifiers are read as absolutely unrestricted. It can be shown that the phenomenon of higher-order vagueness eventually forces fuzzy logical treatments of vagueness to use a fuzzy metalanguage, with consequent repercussions for what first-order principles are validated. The difficulty of proving the completeness of first-order intuitionistic logic on its intended interpretation by intuitionistically rather than just classically valid means is a more familiar example. These case studies will be discussed in some detail to reveal a variety of ways in which even metalogic is metaphysically contested, substantial and non-neutral. (shrink)
Contributors to this volume approach Rawls's idea from a number of perspectives: its philosophical foundations, institutional implications, and possible connections to the future of left-of-center politics.
In response to Paul Boghossian's objections in ‘Inferentialism and the epistemology of logic’, this paper defends counterexamples offered by Paolo Casalegno and the author to an inferentialist account of what it is to understand a logical constant, on which Boghossian had relied in his explanation of our entitlement to reason according to basic logical principles. The importance for understanding is stressed of non-inferential aspects of the use of logical constants. Boghossian's criteria for individuating concepts are also queried.
In Crispin Wright's ‘Meaning and Assertibility’, the main point of disagreement with Paolo Casalegno's critique of verificationist semantics in ‘The Problem of Non-conclusiveness’ concerns Wright's diagnosis of one of Casalegno's arguments as depending on an over-estimation of the proper explanatory task of a semantic theory. The present note argues that there is no such dependence.
Abstract: Some proponents of “experimental philosophy” criticize philosophers' use of thought experiments on the basis of evidence that the verdicts vary with truth-independent factors. However, their data concern the verdicts of philosophically untrained subjects. According to the expertise defence, what matters are the verdicts of trained philosophers, who are more likely to pay careful attention to the details of the scenario and track their relevance. In a recent article, Jonathan M. Weinberg and others reply to the expertise defence that there (...) is no evidence for such expertise. They now receive a reply in this article, which argues that they have misconstrued the dialectical situation. Since they have produced no evidence that philosophical training is less efficacious for thought experimentation than for other cognitive tasks for which they acknowledge that it produces genuine expertise, such as informal argumentation, they have produced no evidence for treating the former more sceptically than the latter. (shrink)
Mental competence, or ‘mental capacity’ as it is referred to in recent legislation in the UK, is a concept that is expanding rapidly as a common currency in health and social care services. Neelke Doorn’s “Anthropological Reflection on the Concept of Competence” makes for fascinating and highly relevant reading and the legal and ethical discussions she describes taking place in the Netherlands would appear to echo many of those that have occurred in the UK over the last 5 to 10 (...) years, but with some significant differences. However, Doorn’s new conceptualization of mental competence causes some concerns, particularly if it was to be applied in services currently provided to people where their mental capacity may be .. (shrink)
Necessitism is the view that necessarily everything is necessarily something; contingentism is the negation of necessitism. The dispute between them is reminiscent of, but clearer than, the more familiar one between possibilism and actualism. A mapping often used to ‘translate’ actualist discourse into possibilist discourse is adapted to map every sentence of a first-order modal language to a sentence the contingentist (but not the necessitist) may regard as equivalent to it but which is neutral in the dispute. This mapping enables (...) the necessitist to extract a ‘cash value’ from what the contingentist says. Similarly, a mapping often used to ‘translate’ possibilist discourse into actualist discourse is adapted to map every sentence of the language to a sentence the necessitist (but not the contingentist) may regard as equivalent to it but which is neutral in the dispute. This mapping enables the contingentist to extract a ‘cash value’ from what the necessitist says. Neither mapping is a translation in the usual sense, since necessitists and contingentists use the same language with the same meanings. The former mapping is extended to a second-order modal language under a plural interpretation of the second-order variables. It is proved that the latter mapping cannot be. Thus although the necessitist can extract a ‘cash value’ from what the contingentist says in the second-order language, the contingentist cannot extract a ‘cash value’ from some of what the necessitist says, even when it raises significant questions. This poses contingentism a serious challenge. (shrink)
Second-order logic and modal logic are both, separately, major topics of philosophical discussion. Although both have been criticized by Quine and others, increasingly many philosophers find their strictures uncompelling, and regard both branches of logic as valuable resources for the articulation and investigation of significant issues in logical metaphysics and elsewhere. One might therefore expect some combination of the two sorts of logic to constitute a natural and more comprehensive background logic for metaphysics. So it is somewhat surprising to find (...) that philosophical discussion of secondorder modal logic is almost totally absent, despite the pioneering contribution of Barcan. (shrink)
It is known that indicative and subjunctive conditionals interact differently with a rigidifying "actually" operator. The paper studies this difference in an abstract setting. It does not assume the framework of possible world semantics, characterizing "actually" instead by the type of logically valid formulas to which it gives rise. It is proved that in a language with such features all sentential contexts that are congruential (in the sense that they preserve logical equivalence) are extensional (in the sense that they preserve (...) material equivalence). For a subjunctive conditional, the natural conclusion to draw is that it is non-congruential. It is much harder to defend the claim that an indicative conditional is non-congruential. The pressure to treat the indicative conditional as truth-functional is correspondingly greater. The implications of these results for attempts to interpret the indicative conditional as an epistemic or doxastic operator are assessed. (shrink)
Two opposing tendencies in the philosophy of language go by the names of ‘referentialism’ and ‘inferentialism’ respectively. In the crudest version of the contrast, the referentialist account of meaning gives centre stage to the referential semantics for a language, which is then used to explain the inference rules for the language, perhaps as those which preserve truth on that semantics (since a referential semantics for a language determines the truth-conditions of its sentences). By contrast, the inferentialist account of meaning gives (...) centre stage to the inference rules for the language, which are then used to explain its referential semantics, perhaps as the semantics on which the rules preserve truth. On pain of circularity, we cannot combine both directions of explanation. (shrink)
First, some reminiscences. In the years 1973-80, when I was an undergraduate and then graduate student at Oxford, Michael Dummett’s formidable and creative philosophical presence made his arguments impossible to ignore. In consequence, one pole of discussion was always a form of anti-realism. It endorsed something like the replacement of truth-conditional semantics by verification-conditional semantics and of classical logic by intuitionistic logic, and the principle that all truths are knowable. It did not endorse the principle that all truths are known. (...) Nor did it mention the now celebrated argument, first published by Frederic Fitch (1963), that if all truths are knowable then all truths are known. (shrink)
Operational epistemology is, to a first approximation, the attempt to provide cognitive rules such that one is in principle always in a position to know whether one is complying with them. In Knowledge and its Limits, I argue that the only such rules are trivial ones. In this paper, I generalize the argument in several ways to more thoroughly probabilistic settings, in order to show that it does not merely demonstrate some oddity of the folk epistemological conception of knowledge. Some (...) of the generalizations involve a formal semantic framework for treating epistemic probabilities of epistemic probabilities and expectations of expectations. The upshot is that operational epistemology cannot work, and that knowledge-based epistemology has the right characteristics to avoid its problems. (shrink)
In conversations between native speakers, words such as ‘same’ and ‘identical’ do not usually cause much difficulty. We take it for granted that others use them with the same sense as we do. If it is unclear whether numerical or qualitative identity is intended, a brief gloss such as ‘one thing not two’ for the former or ‘exactly alike’ for the latter removes the unclarity. In this paper, numerical identity is intended. A particularly conscientious and logically aware speaker might explain (...) what ‘identical’ means in her.. (shrink)
Roy Sorensen's criticism of my use of margin for error principles to explain ignorance in borderline cases fails because it misidentifies the relevant margin for error principles. His alternative explanation in terms of truth-maker gaps is briefly criticized.
Metaphysical modalities are definable from counterfactual conditionals, and the epistemology of the former is a special case of the epistemology of the latter. In particular, the role of conceivability and inconceivability in assessing claims of possibility and impossibility can be explained as a special case of the pervasive role of the imagination in assessing counterfactual conditionals, an account of which is sketched. Thus scepticism about metaphysical modality entails a more far-reaching scepticism about counterfactuals. The account is used to question the (...) significance of the distinction between a priori and a posteriori knowledge. (shrink)
The second volume in the Blackwell Brown Lectures in Philosophy, this volume offers an original and provocative take on the nature and methodology of philosophy. Based on public lectures at Brown University, given by the pre-eminent philosopher, Timothy Williamson Rejects the ideology of the 'linguistic turn', the most distinctive trend of 20th century philosophy Explains the method of philosophy as a development from non-philosophical ways of thinking Suggests new ways of understanding what contemporary and past philosophers are doing.
This paper is concerned with formal solutions to the lottery paradox on which high probability defeasibly warrants acceptance. It considers some recently proposed solutions of this type and presents an argument showing that these solutions are trivial in that they boil down to the claim that perfect probability is sufficient for rational acceptability. The argument is then generalized, showing that a broad class of similar solutions faces the same problem. An argument against some formal solutions to the lottery paradox The (...) argument generalized Some variations Adding modalities Anticipated objections. (shrink)
0. Platitudinously, cognitive science is the science of cognition. Cognition is usually defined as something like the process of acquiring, retaining and applying knowledge. To a first approximation, therefore, cognitive science is the science of knowing. Knowing is a relation between the knower and the known. Typically, although not always, what is known involves the environment external to the knower. Thus knowing typically involves a relation between the agent and the external environment. It is not internal to the agent, for (...) the internal may be the same whether or not it is related to the external in a way that constitutes knowing. Cognition enables agents to achieve their goals by adjusting their actions appropriately to the environment. Such adjustment requires what is internal to the agent to be in some sense in line with what is external; that matching depends on both internal and external sides. Thus if cognitive science were restricted to what is internal to the agent, it would lose sight of its primary object of study. Although cognition depends on both the internal and the external, one can try to analyse it into internal and external factors. Call a state S narrow if and only if whether an agent is in S at a time t depends only on the total internal qualitative state of S at t, so that if one agent in one possible situation is internally an exact duplicate of another agent.. (shrink)
The paper criticizes epistemological conceptions of analytic or conceptual truth, on which assent to such truths is a necessary condition of understanding them. The critique involves no Quinean scepticism about meaning. Rather, even granted that a paradigmatic candidate for analyticity is synonymy with a logical truth, both the former and the latter can be intelligibly doubted by linguistically competent deviant logicians, who, although mistaken, still constitute counterexamples to the claim that assent is necessary for understanding. There are no analytic or (...) conceptual truths in the epistemological sense. The critique is extended to purportedly analytic inference rules. An alternative account is sketched on which understanding a word is a matter of participation in a linguistic practice, while synonymy and concept identity consist in sameness of truth-conditional semantic properties. Although there are philosophical questions about concepts, the idea that philosophical questions in general are conceptual questions generates only an illusion of insight into philosophical methodology. (shrink)
This paper is concerned with formal solutions to the lottery paradox on which high probability defeasibly warrants acceptance. It considers some recently proposed solutions of this type and presents an argument showing that these solu are trivial in that they boil down to the claim that perfect probability is sufficient for rational acceptability. The argument is then generalized, showing that a broad class of similar solutions faces the same problem.
§0. A familiar if obscure idea: an indicative conditional presents its consequent as holding in the actual world on the supposition that its antecedent so holds, whereas a subjunctive conditional merely presents its consequent as holding in a world, typically counterfactual, in which its antecedent holds. Consider this pair.
Imagine a philosophy conference in Presocratic Greece. The hot question is: what are things made of? Followers of Thales say that everything is made of water, followers of Anaximenes that everything is made of air, and followers of Heraclitus that everything is made of fire. Nobody is quite clear what these claims mean, and some question whether the founders of the respective schools ever made them. But amongst the groupies there is a buzz about all the recent exciting progress. The (...) mockers and doubters make plenty of noise too. They point out that no resolution of the dispute between the schools is in sight. They diagnose Thales, Anaximenes and Heraclitus as suffering from a tendency to overgeneralize. We can intelligibly ask what bread is made of, or what houses are made of, but to ask what things in general are made of is senseless, some suggest, because the question is posed without any conception of how to verify an answer; language has gone on holiday. Paleo-pragmatists invite everyone to relax, forget their futile pseudo-inquiries and do something useful instead. (shrink)
0. Logic is sometimes conceived as metaphysically neutral, so that nothing controversial in metaphysics is logically valid. That conception devastates logic. Just about every putative principle of logic has been contested on metaphysical grounds. According to some, future contingencies violate the law of excluded middle; according to others, the set of all sets that are not members of themselves makes a contradiction true. Even the structural principle that chaining together valid arguments yields a valid argument has been rejected in response (...) to sorites paradoxes. In each case, a deviant metaphysics corresponds to the deviant logic. Of course, if one is trying to persuade deviant metaphysicians of the error of their ways, one is unlikely to get far by relying on logical principles that they reject. But that obvious dialectical exigency stably marks out no realm of logic. Each logical principle has persuasive force in some dialectical contexts and not in others. We do better to admit that logic has metaphysically contentious implications, and embrace them ─ if we know what they are. (shrink)
Many philosophers, following David Lewis, believe that we should look to counterpart theory, not quantified modal logic, as a means of understanding modal discourse. We argue that this is a mistake. Significant parts of modal discourse involve either implicit or explicit reference to what is actually the case, raising the question of how talk about actuality is to be represented counterpart-theoretically. By considering possible modifications of Lewis's counterpart theory, including actual modifications due to Graeme Forbes and Murali Ramachandran, we argue (...) that no coherent version of counterpart theory can provide a plausible representation of talk about actuality, and so, we conclude, counterpart theory should be rejected. (shrink)
It is natural to ask under what conditions negating a conditional is equivalent to negating its consequent. Given a bivalent background logic, this is equivalent to asking about the conjunction of Conditional Excluded Middle (CEM, opposite conditionals are not both false) and Weak Boethius' Thesis (WBT, opposite conditionals are not both true). In the system CI.0 of consequential implication, which is intertranslatable with the modal logic KT, WBT is a theorem, so it is natural to ask which instances of CEM (...) are derivable. We also investigate the systems CIw and CI of consequential implication, corresponding to the modal logics K and KD respectively, with occasional remarks about stronger systems. While unrestricted CEM produces modal collapse in all these systems, CEM restricted to contingent formulas yields the Alt2 axiom (semantically, each world can see at most two worlds), which corresponds to the symmetry of consequential implication. It is proved that in all the main systems considered, a given instance of CEM is derivable if and only if the result of replacing consequential implication by the material biconditional in one or other of its disjuncts is provable. Several related results are also proved. The methods of the paper are those of propositional modal logic as applied to a special sort of conditional. (shrink)
A striking feature of the traditional armchair method of philosophy is the use of imaginary examples: for instance, of Gettier cases as counterexamples to the justified true belief analysis of knowledge. The use of such examples is often thought to involve some sort of a priori rational intuition, which crude rationalists regard as a virtue and crude empiricists as a vice. It is argued here that, on the contrary, what is involved is simply an application of our general cognitive capacity (...) to handle counterfactual conditionals, which is not exclusively a priori and is not usefully conceived as a form of rational intuition. It is explained how questions of metaphysical possibility and necessity are equivalent to questions about counterfactuals, and the epistemology of the former (in particular, the role of conceiving or imagining) is a special case of the epistemology of the latter. A non-imaginary Gettier case is presented in order to show how little difference it makes. (shrink)
§I schematises the evidence for an understanding of ‘know’ and other terms of epistemic appraisal that embodies contextualism or subject-sensitive invariantism, and distinguishes between those two approaches. §II argues that although the cases for contextualism and sensitive invariantism rely on a principle of charity in the interpretation of epistemic claims, neither approach satisfies charity fully, since both attribute metalinguistic errors to speakers. §III provides an equally charitable anti-sceptical insensitive invariantist explanation of much of the same evidence as the result of (...) psychological bias caused by salience effects. §IV suggests that the explanation appears to have implausible consequences about practical reasoning, but also that applications of contextualism or sensitive invariantism to the problem of scepticism have such consequences. §V argues that the inevitable difference between appropriateness and knowledge of appropriateness in practical reasoning, closely related to the difference between knowledge and knowledge of knowledge, explains the apparent implausibility. (shrink)
Scepticism is a disease in which healthy mental processes run pathologically unchecked. Our cognitive immunity system, designed to protect our conception of the world from harmful errors, turns destructively on that conception itself. Since we have false beliefs, we benefit from the ability to detect our mistakes; removing our errors tends to do us good. Our cognitive immunity system should be able to destroy bad old beliefs, not just prevent the influx of new ones. But that ability sometimes becomes indiscriminate, (...) and destroys good beliefs too. That can happen in several ways. I start by considering two of them. (shrink)
Contextualism is relativism tamed. Relativism about truth is usually motivated by the idea of no-fault disagreement. Imagine two parties: one (she) says ‘P’; the other (he) says ‘Not P’.1 Apparently, if P then ‘P’ is true and ‘Not P’ false, so she is right and he is wrong; if not P then ‘P’ is false and ‘Not P’ true, so he is right and she is wrong. In both cases, there is an asymmetry between the two parties. Since P or (...) not P (by the law of excluded middle), there is indeed an asymmetry between them, one way or the other. Yet the two parties may strike a neutral observer as on a par, equally intelligent, informed, perceptive and alert. Relativists about truth strive to dissolve the unpleasant asymmetry: ‘”P” is true for her; “Not P” is true for him’. Trouble starts when we ask what the relativists mean by ‘for’ in the construction ‘true for X’. If to call something true ‘for’ X is just to say that X believes that it is true, then the attempted dissolution amounts to this: ‘She believes that “P” is true; he believes that “Not P” is true’. But that is to add no more than that both parties believe that they are right; it does nothing to undermine the argument for an asymmetry between them. Relativists had better mean something else by ‘true for X’. When asked to explain what else they mean, wild relativists bluster incoherently. Contextualists, by contrast, have a clear answer. A sentence is true for X if and only if it is true as uttered by X, true relative to a context in which X is the speaker. Such relativism is tame because the relativity to context in the truth-value of a sentence allows for absoluteness in the truth-value of what the sentence is used to say in a given context. When she says ‘P’, she speaks truly: not just truly for her, but absolutely truly. When he says ‘Not P’, he too speaks truly: not just truly for him, but absolutely truly. The argument for asymmetry 1 assumes that, when she says ‘P’, she speaks truly if and only if P, and when he says ‘Not P’, he speaks truly if and only if not P.. (shrink)
The core of Tony Brueckner’s critique in ‘Knowledge, Evidence, and Skepticism according to Williamson’ is his claim in section 5 that my account of perceptual knowledge has an unacceptable consequence. My reply will concentrate on that claim and largely ignore the rest of Brueckner’s interesting discussion, for it is easy to check that the claim is essential to Brueckner’s argument against my analysis of skepticism and evidence.
A striking feature of the traditional armchair method of philosophy is the use of imaginary examples: for instance, of Gettier cases as counterexamples to the justified true belief analysis of knowledge. The use of such examples is often thought to involve some sort of a priori rational intuition, which crude rationalists regard as a virtue and crude empiricists as a vice. It is argued here that, on the contrary, what is involved is simply an application of our general cognitive capacity (...) to handle counterfactual conditionals, which is not exclusively a priori and is not usefully conceived as a form of rational intuition. It is explained how questions of metaphysical possibility and necessity are equivalent to questions about counterfactuals, and the epistemology of the former (in particular, the role of conceiving or imagining) is a special case of the epistemology of the latter. A non-imaginary Gettier case is presented in order to show how little difference it makes. (shrink)
1. What are called ‘intuitions’ in philosophy are just applications of our ordinary capacities for judgement. We think of them as intuitions when a special kind of scepticism about those capacities is salient. 2. Like scepticism about perception, scepticism about judgement pressures us into conceiving our evidence as facts about our internal psychological states: here, facts about our conscious inclinations to make judgements about some topic rather than facts about the topic itself. But the pressure should be resisted, for it (...) rests on bad epistemology: specifically, on an impossible ideal of unproblematically identifiable evidence. 3. Our resistance to scepticism about judgement is not simply epistemic conservativism, for we resist it on behalf of others as well as ourselves. A reason is needed for thinking that beliefs tend to be true. 4. Evolutionary explanations of the tendency assume what they should explain. Explanations that appeal to constraints on the determination of reference are more promising. Davidson’s truth-maximizing principle of charity is examined but rejected. 5. An alternative principle is defended on which the nature of reference is to maximize knowledge rather than truth. It is related to an externalist conception of mind on which knowing is the central mental state. 6. The knowledge-maximizing principle of charity explains why scenarios for scepticism about judgement do not warrant such scepticism, although it does not explain how we know in any particular case. We should face the fact that evidence is always liable to be contested in philosophy, and stop using talk of intuition to disguise this unpleasant truth from ourselves. (shrink)
A kind of intellectual project characteristic of Ernest Sosa is to resolve an apparently flat-out dispute by showing that it is not after all a zero-sum game. His irenic goal is to do justice to both sides and give each of them most of what it wants. In his subtle paper ‘Abilities, Concepts, and Externalism’ he applies this strategy to the dispute between internalism and externalism in the philosophy of mind. It is a pleasure to engage in discussion with a (...) philosopher of Sosa’s fair-mindedness and analytical skills. (shrink)
Here is an account of logical consequence inspired by Bolzano and Tarski. Logical validity is a property of arguments. An argument is a pair of a set of interpreted sentences (the premises) and an interpreted sentence (the conclusion). Whether an argument is logically valid depends only on its logical form. The logical form of an argument is fixed by the syntax of its constituent sentences, the meanings of their logical constituents and the syntactic differences between their non-logical constituents, treated as (...) variables. A constituent of a sentence is logical just if it is formal in meaning, in the sense roughly that its application is invariant under permutations of individuals.1 Thus ‘=’ is a logical constant because no permutation maps two individuals to one or one to two; ‘∈’ is not a logical constant because some permutations interchange the null set and its singleton. Truth functions, the usual quantifiers and bound variables also count as logical constants. An argument is logically valid if and only if the conclusion is true under every assignment of semantic values to variables (including all non-logical expressions) under which all its premises are true. A sentence is logically true if and only if the argument with no premises of which it is the conclusion is logically valid, that is, if and only if the sentence is true under every assignment of semantic values to variables. An interpretation assigns values to all variables. (shrink)
[Paul Boghossian] 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. (...) /// [Timothy Williamson] The paper challenges the inferentialist account of concept possession that Paul Boghossian takes as a premise in his account of the transmission of justification by deductive reasoning in his paper 'Blind Reasoning'. Unorthodox speakers who reject the inferences in an alleged possession condition can still have the concept by understanding a word for it. In that sense, the inferences are not analytic. Inferentialist accounts of logical constants, theoretical terms (using the Ramsey-Carnap-Lewis method) and pejorative expressions such as 'Boche' are examined and rejected. It is suggested that epistemological questions cannot be reduced to questions in the theory of thought and meaning. (shrink)
On reading the last sentence, did you interpret me as saying falsely that everything — everything in the entire universe — was packed into my carry-on baggage? Probably not. In ordinary language, ‘everything’ and other quantifiers (‘something’, ‘nothing’, ‘every dog’, ...) often carry a tacit restriction to a domain of contextually relevant objects, such as the things that I need to take with me on my journey. Thus a sentence of the form ‘Everything Fs’ is true as uttered in a (...) context C if and only if everything that is relevant in C satisfies the predicate ‘F’; ‘everything’ ranges just over the contextually relevant things. Such generality is restricted in a context-relative way. (shrink)
When I take off my glasses, the world looks blurred. When I put them back on, it looks sharpedged. I do not think that the world really was blurred; I know that what changed was my relation to the distant physical objects ahead, not those objects themselves. I am more inclined to believe that the world really is and was sharp-edged. Is that belief any more reasonable than the belief that the world really is and was blurred? I see more (...) accurately with my glasses on than off, so visual appearances when they are on have some cognitive priority over visual appearances when they are off. If I must choose which kind of visual appearance to take at face value, I will choose the sharp-edged look. But what should I think when I see a mist, which looks very blurred however well I am seeing? Indeed, why choose to take any of the looks at face value? Why not regard all the choices as illegitimate projections of ways of seeing the world onto the world itself? (shrink)
If you’ve read the first five hundred pages of this book, you’ve read most of it (we assume that ‘most’ requires more than ‘more than half’). The set of natural numbers n such that the first n pages are most of this book is nonempty. Therefore, by the least number principle, it has a least member k. What is k? We do not know. We have no idea how to find out. The obstacle is something about the term ‘most’. It (...) is recognisably the same feature as the feature of ‘heap’ that prevents us from finding an answer to the question ‘How many grains make a heap?’ and the feature of many other expressions that prevents us from finding answers to similar questions involving them. Call this feature, whatever its underlying nature, vagueness. (shrink)
The paper is a critique of Terry Horgan's transvaluationist theory of vagueness. It argues that Horgan's formulations equivocate between a semantic 'ought' and a semantic 'is'. On one reading, transvaluationism is trivially inconsistent. On another reading, it is consistent, but also consistent with an epistemic account of vagueness. In addition, the paper criticizes Horgan's attempt to recruit supervaluationism as a form of transvaluationism and his argument against vagueness in the world.
It seems obvious that I could have failed to exist. My parents could easily never have met, in which case I should never have been conceived and born. The like applies to everyone. More generally, it seems plausible that whatever exists in space and time could have failed to exist. Events could have taken an utterly different course. Our existence, like most other aspects of our lives, appears frighteningly contingent. It is therefore surprising that there is a proof of my (...) necessary existence, a proof that generalizes to everything whatsoever. I will explain the proof and discuss what to make of it. A first reaction is that a ‘proof’ of such an outrageous conclusion must contain some dreadful fallacy. Yet the proof does not collapse under scrutiny. Further reflection suggests that, suitably interpreted, it may be sound. So interpreted, the conclusion is not outrageous, although it may not be the view you first thought of. (shrink)
In their paper “Vagueness, Ignorance, and Margins for Error” Kenton Machina and Harry Deutsch criticize the epistemic theory of vagueness. This paper answers their objections. The main issues discussed are: the relation between meaning and use; the principle of bivalence; the ontology of vaguely specified classes; the proper form of margin for error principles; iterations of epistemic operators and semantic compositionality; the relation or lack of it between quantum mechanics and theories of vagueness.
Many philosophers believe that there is a fundamental distinction between knowing that something is the case and knowing how to do something. According to Gilbert Ryle, to whom the insight is credited, knowledge-how is an ability, which is in turn a complex of dispositions. Knowledge-that, on the other hand, is not an ability, or anything similar. Rather, knowledge-that is a relation between a thinker and a true proposition.
The paper defends the intelligibility of unrestricted quantification. For any natural number n, 'There are at least n individuals' is logically true, when the quantifier is unrestricted. In response to the objection that such sentences should not count as logically true because existence is contingent, it is argued by consideration of cross-world counting principles that in the relevant sense of 'exist' existence is not contingent. A tentative extension of the upward L?wenheim-Skolem theorem to proper classes is used to argue that (...) a sound and complete axiomatization of the logic of unrestricted universal quantification results from adding all sentences of the form 'There are at least n individuals' as axioms to a standard axiomatization of the first-order predicate calculus. (shrink)
Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)
If semantic paradoxes such as the Liar arise because ‘true’ and other metalinguistic expressions can change their reference with changes of linguistic context, is that due to indexicality (they have the same linguistic meaning as reference changes) or ambiguity (their linguistic meaning itself changes)? An argument from communication that appears to favour the indexicality interpretation is not compelling. This paper defends the ambiguity interpretation. It is left open whether its considerations generalize to other kinds of paradox.
