One strategy for blocking Chalmers's overall case against physicalism has been to deny his claim that showing that phenomenal properties are in some sense physical requires an a priori entailment of the phenomenal truths from the physical ones. Here I avoid this well-trodden ground and argue instead that an a priori entailment of the phenomenal truths from the physical ones does not require an analysis in the Jackson/Chalmers sense. This is to sever the dualist's link between (...) conceptual analysis and a priori entailment by showing that the lack of the former does not imply the absence of the latter. Moreover, given the role of the argument from conceptual analysis in Chalmers's overall case for dualism, undermining that argument effectively undermines that case as a whole in a way that, I'll argue, undermining the conceivability arguments as stand-alone arguments does not. (shrink)

In this paper I examine Chalmers and Jackson’s defence of the a priori entailment thesis, that is, the claim that microphysical truths a priori entail ordinary non-phenomenal truths such as ‘water covers 60% of the Earth surface’, which they use as a premise for an argument against the possibility of a reductive explanation of consciousness. Their argument relies on a certain view about the possession conditions of macroscopic concepts such as WATER, known as ascriptivism. In the paper (...) I distinguish two versions of ascriptivism: reductive versus non-reductive ascriptivism. According to reductive ascriptivism, competent users of a concept have the ability to infer truths involving such concept from lower-level truths, whereas according to non-reductive ascriptivism, all that is required in order to be a competent user of a concept is to be able to infer truths involving that concept from other truths, which need not be lower-level truths. I argue, first, that the a priori entailment thesis is committed to reductive ascriptivism, and secondly, that reductive ascriptivism is problematic because it trivializes the notion of a priori knowledge. Therefore, I conclude that Chalmers and Jackson have not presented a convincing case for the claim that microphysical truths entail ordinary non-phenomenal truths a priori, especially when we understand this claim in the sense that is relevant for their argument against the possibility of a reductive explanation of consciousness. (shrink)

The principle of mass additivity states that the mass of a composite object is the sum of the masses of its elementary components. Mass additivity is true in Newtonian mechanics but false in special relativity. Physicists have explained why mass additivity is true in Newtonian mechanics by reducing it to Newton’s microphysical laws. This reductive explanation does not fit well with deducibility theories of reductive explanation such as the modern Nagelian theory of reduction, and the a priori entailment (...) theory of reduction that is prominent in the philosophy of mind. Nonetheless, I argue that a reconstruction of the explanation that incorporates distinctively philosophical concepts in fact fits both theories. I discuss the implications of this result for both theories and for the reductive explanation of consciousness. (shrink)

Sohn-Rethel’s theory undermines the line of thought that, from Kant to deconstruction, severs being or the thing from representation, by showing that the Kantian a priori categories of thought are a posteriori effects of the relations of things, to the point that it is ‘only through the language of commodities that their owners become rational beings’. This is the thesis of Marx’s theory of ‘commodity fetishism’, and Sohn-Rethel’s work develops the methodology that follows from it. ‘ Realabstraktion’ means that (...) the commodification of things amounts to their transformation into the language that provides the a priori categories of human thought. As a result, far from being inaccessible to representation, being is precisely that which reveals itself whenever the transcendental categories of representation are laid out. Therefore, Sohn-Rethel’s theory entails that not only can one not separate economy from thought but also economy and thought from being, so that there are no three distinct fields – economy, ontology and epistemology – but one: an economic epistemontology. Just as Marx’s ‘commodity fetishism’ introduced the unconscious in both subjectivity and economy – ‘they do this without knowing it’ – Sohn-Rethel analysed all economic, intellectual and practical spheres in terms of the fundamental distinction between consciousness and the unconscious. The article also points to certain corrections that Marx’s own theory indicates need to be made in Sohn-Rethel’s account, particularly regarding the source of abstraction, the role of coined money, and the difference between capitalist and pre-capitalist modes of production and exchange. (shrink)

Broadly speaking, a naturalistic approach to epistemology seeks to explain human knowledge – and justification in particular – as a phenomenon in the natural world, in keeping with the tenets of naturalism. Naturalism is typically defined, in part, by a commitment to scientific method as the only legitimate means of attaining knowledge of the natural world. Naturalism is often thought to entail empiricism by virtue of this methodological commitment. However, scientific methods themselves may incorporate a priori elements, so empiricism (...) does not follow from the methodological commitments of naturalism alone. And given a suitably-naturalistic conception of the a priori, a priori forms of justification may be compatible with naturalism generally. A priori justification is, in principle, compatible with naturalism – and hence naturalistic epistemologies – if the a priori is understood in a way that is free of some of the inessential properties that have been associated with the concept. I argue that some of the more prominent strategies for accommodating normative notions within a naturalistic framework allow for the possibility of a priori justification. These include reliabilism, instrumental rationality, and nonfactualism about justification. A priori justification thus need not be seen as standing in opposition to all naturalistic epistemologies. It is only with nonnormative naturalistic epistemologies that a priori justification per se is incompatible, and this only because the notion of justification itself has no role to play within a nonnormative approach to epistemology. (shrink)

In his recent book Constructing the World, David Chalmers defends A Priori Scrutability, the thesis that there is a compact class of truths such that for any truth p, a Laplacian intellect could know a priori that if the truths in that class hold, then p. In this paper, I develop an objection to Chalmers’ thesis that focuses on his treatment of a so-called that’s-all truth. My objection draws on Theodore Sider’s discussion of border-sensitive properties, and also on (...) the causal phenomenon of double prevention. (shrink)

According to David Chalmers and Frank Jackson, conceptual competence puts one in a position to have a priori knowledge of conditional claims of the form ‘If my environment is thus and so, then water = H2O’. The rationale for this position, I argue, rests on controversial semantic assumptions about the individuation of meanings or concepts. I sketch a new model of conceptual competence, which undermines the apriority of such conditionals.

I defend the claim that physicalism is not committed to the view that non-phenomenal macrophysical truths are a priori entailed by the conjunction of microphysical truths , basic indexical facts , and a 'that's all' claim . I do so by showing that Chalmers and Jackson's most popular and influential argument in support of the claim that PIT ⊃ M is a priori, where 'M' stands for any ordinary, non-phenomenal, macroscopic truth, falls short of establishing its conclusion. My (...) objection to Chalmers and Jackson's argument takes the form of a nested dilemma. Let 'Conceptual Competence Principle ' stand for the following claim: for any complete microphysical description D of a world w, a subject who is in possession of and competent with a macrophysical concept C is capable of determining a priori the extension of C. Either Jackson and Chalmers accept CCP or not. If the latter, then they cannot demonstrate that the conditional PIT ⊃ M is a priori. If the former, then they have a choice: they can either cite reasons that support the principle or argue that the principle should be taken for granted since it is entailed by the very notion of conceptual competence. But both alternatives are problematic. In regard to the first horn of this latter dilemma, I show not only that there are no good reasons to support the principle, but that there are also reasons to reject it. In regard to the second horn, I show that it cannot be the case that CCP is part of the very notion of conceptual competence. The conceptual capacity expressed by CCP requires that certain bridge principles or conditionals, which link the microphysical level to the macroscopic level, are either implicitly or explicitly given to the subject. But, as I argue, Chalmers and Jackson have no way of accounting for these bridge principles or conditionals in a manner that does not trivialize their position. (shrink)

On rationalist infallibilism, a wide range of both (i) analytic and (ii) synthetic a priori propositions can be infallibly justified, i.e., justified in a way that is truth-entailing. In this paper, I examine the second thesis of rationalist infallibilism, what might be called ‘synthetic a priori infallibilism’. Exploring the seemingly only potentially plausible species of synthetic a priori infallibility, I reject the infallible justification of so-called self-justifying propositions.

On rationalist infallibilism, a wide range of both (i) analytic and (ii) synthetic a priori propositions can be infallibly justified (or absolutely warranted), i.e., justified to a degree that entails their truth and precludes their falsity. Though rationalist infallibilism is indisputably running its course, adherence to at least one of the two species of infallible a priori justification refuses to disappear from mainstream epistemology. Among others, Putnam (1978) still professes the a priori infallibility of some category (i) (...) propositions, while Burge (1986, 1988, 1996) and Lewis (1996) have recently affirmed the a priori infallibility of some category (ii) propositions. In this paper, I take aim at rationalist infallibilism by calling into question the a priori infallibility of both analytic and synthetic propositions. The upshot will be twofold: first, rationalist infallibilism unsurprisingly emerges as a defective epistemological doctrine, and second, more importantly, the case for the a priori infallibility of one or both categories of propositions turns out to lack cogency. (shrink)

According to Perceptual Fundamentalism we can have justified perceptual beliefs solely in virtue of having perceptual experiences with corresponding contents. Recently, it has been argued that Perceptual Fundamentalism entails that it is possible to gain an a priori justified belief that perception is reliable by engaging in a suppositional reasoning process of a priori bootstrapping. But I will show that Perceptual Fundamentalists are not committed to a priori bootstrapping being a rational reasoning process. On the most plausible (...) versions of Perceptual Fundamentalism, a priori bootstrapping cannot be used to rationally support anti-sceptical beliefs about the reliability of perception. Moreover, seeing why Perceptual Fundamentalists are not committed to a priori bootstrapping will help us to better understand the nature of the perceptual entitlements that Perceptual Fundamentalists posit, or at least should posit. (shrink)

In this paper, I argue against the view there are contingent a priori truths, and against the related view that there are contingent logical truths. I will suggest that in general, predicates ›a priori‹ and ›contingent‹ are implicitly relativized to circumstances, and argue that apriority entails necessity, whenever the two are relativized to the same circumstance. I will then criticize the idea, inspired by David Kaplan's framework, of contingent contents "knowable under a priori characters." I will also (...) argue, against Kaplan, that sentences of the form »The actual F is F« do not deserve the status of logical truths, since what they express is neither necessary nor a priori. (shrink)

The topic of this article is the closure of a priori knowability under a priori knowable material implication: if a material conditional is a priori knowable and if the antecedent is a priori knowable, then the consequent is a priori knowable as well. This principle is arguably correct under certain conditions, but there is at least one counterexample when completely unrestricted. To deal with this, Anderson proposes to restrict the closure principle to necessary truths and (...) Horsten suggests to restrict it to formulas that belong to less expressive languages. In this article it is argued that Horsten’s restriction strategy fails, because one can deduce that knowable ignorance entails necessary ignorance from the closure principle and some modest background assumptions, even if the expressive resources do not go beyond those needed to formulate the closure principle itself. It is also argued that it is hard to find a justification for Anderson’s restricted closure principle, because one cannot deduce it even if one assumes very strong modal and epistemic background principles. In addition, there is an independently plausible alternative closure principle that avoids all the problems without the need for restriction. (shrink)

Merely conceptual knowledge, not based on specific sensitivity to the referential domain, is not seriously a priori. It is argued here that it is either weakly and superficially a priori, or downright a posteriori. This is done starting from the fact that many of our definitions (or concepts) are recognizably empirically established, and pointing out that recognizably empirical grounding yields superficial apriority. Further, some (first-order) concept analyzing propositions are empirically false about their referents and thus empirically refutable. Therefore, (...) our empirical definitions (or concepts) are fallible and empirically revisable: they can turn out to be incorrect about the intended satisfiers of the concept defined, and their concept analyzing propositions to be false. Now, empirical revisability is incompatible with strong apriority (and entails at best a weak apriority or aposteriority). The result is quite shocking: analyticity does not entail apriority. (shrink)

What has come to be known as “a priori physicalism” is the thesis, roughly, that the non-physical truths in the actual world can be deduced a priori from a complete physical description of the actual world. To many contemporary philosophers, a priori physicalism seems extremely implausible. In this paper I distinguish two kinds of a priori physicalism. One sort – strict a priori physicalism – I reject as both unmotivated and implausible. The other sort – (...) liberal a priori physicalism – I argue is both motivated and plausible. This variety of a priori physicalism insists that the necessitation of non-physical truths by the physical facts must be underwritten in a certain fashion by a priori knowledge, but the a priori knowledge need not amount to a simple deduction of the non-physical truths from a complete physical description of the world. Further, this sort of liberal a priori physicalism has the advantage that it offers hope for a genuinely satisfying account of how the physical facts manage to necessitate the facts about phenomenal consciousness – thereby in effect solving the “hard problem” of consciousness. The first half of the paper sets out the motivation for liberal a priori physicalism and its superiority to the strict version; the second half presents one strategy available to the liberal a priori physicalist for showing how consciousness can be accommodated in a purely physical world. (shrink)

This essay reassesses the relation between Kant and Kripke on the relation between necessity and the a priori. Kripke famously argues against what he takes to be the traditional view that a statement is necessary only if it is a priori, where, very roughly, what it means for a statement to be necessary is that it is true and could not have been false and what it means for a statement to be a priori is that it (...) is knowable independently of experience. Call such a view the Entailment Thesis. Along with many Kant scholars, Kripke thinks that Kant endorses the Entailment Thesis. Thus Kripke and many others take his arguments against the Entailment Thesis to tell against Kant and to mark an important point of disagreement with him. I will argue that this is a mistake. Kant does not endorse the Entailment Thesis that Kripke and many others attribute to him. He does endorse two quite different theses concerning the relation between necessity and the a priori, as he conceives them. One is a matter of definition and the other is a very substantial philosophical thesis indeed—to establish it is the aim of the entire Critique of Pure Reason. But Kripke’s arguments against the Entailment Thesis tell against neither of Kant’s theses, as they involve crucially different conceptions of necessity and the a priori. This superficial lack of disagreement masks deep disagreements, but these result from divergent views regarding matters such as realism, modal epistemology, and philosophical methodology; views which Kant does a lot, and Kripke very little, to argue for. (shrink)

Some truths about color are knowable a priori. For example, it is knowable a priori that redness is not identical to the property of being square. This extremely modest and plausible claim has significant philosophical implications, or so I shall argue. First, I show that this claim entails the falsity of standard forms of color functionalism, the view that our color concepts are functional concepts that pick out their referents by way of functional descriptions that make reference to (...) the subjective responses of perceivers. I then argue that, while some sophisticated forms of color functionalism can accommodate the a priori knowability of a truth like “redness is not identical to squareness,” they can only do so by abandoning color realism, the thesis that colors are instantiated by external material objects. In practice, color functionalists are almost invariably color realists. Thus, given extremely modest assumptions concerning what can be known a priori about color, we should conclude that color functionalism, at least in its typical realist form, is false. (shrink)

In his most recent treatment of a priori knowledge, Philip Kitcher argues against what he takes to be the widespread view that our knowledge and warranted belief is 'tradition-independent'. Furthermore, he argues that defeasible conceptions of a priori warrant entail that it is not tradition-independent, a conclusion which he thinks is contrary to what most epistemologists hold. I argue that knowledge is not widely believed to be tradition-independent, and that, while warrant is widely believed to be tradition-independent, Kitcher's (...) arguments show neither that this widespread view is mistaken nor that it conflicts with defeasible a warrant. I conjecture that Kitcher may be misled by a lack of clarity regarding the analysandum designated by 'warrant'. (shrink)

The aim of the present work is to demonstrate that physicalism and a priori knowledge are epistemologically incompatible. The possibility of a priori knowledge on physicalism will be considered in the light of Edmund Gettier’s insight regarding knowledge. In the end, it becomes apparent that physicalism entails an unavoidable disconnect between a priori beliefs and their justificatory grounds; thus precluding the possibility of a priori knowledge. Consequently, a priori knowledge and physicalism are epistemologically incompatible.

Both a priori physicalism and a posteriori physicalism combine a metaphysical and an epistemological thesis. They agree about the metaphysical thesis: our world is wholly physical. Most agree that this requires everything that there is must be necessitated by the sort of truths described by physics. If we call the conjunction of the basic truths of physics P, all physicalists agree that P entails for any truth Q. Where they disagree is whether or not this entailment can be (...) known a priori. The a priori physicalist says it can, the a posteriori physicalist says it cannot. Though a posteriori physicalism is probably the dominant view, it is really a surprising and somewhat unlikely stance. In this article, the nature of the view is discussed, and two arguments are presented that should cause us to look again at the potential of a priori physicalism. (shrink)

The attempt to hold both anti-individualism and privileged self-knowledge may have the absurd consequence that someone could know a priori propositions that are knowable only empirically. This would be so if such an attempt entailed that one could know a priori both the contents of one’s own thoughts and the anti-individualistic entailments from those thought-contents to the world. For then one could also come to know a priori the empirical conditions entailed by one’s thoughts. But I argue (...) that there is no construal of a priori knowledge that could be used to raise an incompatibility problem of this sort. First, I suggest that the incompatibilist a priori must be a stipulative one, since in none of the main philosophical traditions does knowledge of the contents of one’s thoughts count as a priori. Then, I show that under various possible construals of a priori, the incompatibilist argument would be invalid: either a fallacy of equivocation or an argument without a plausible closure principle guaranteeing transmission of epistemic status from premises to conclusion. Finally, I maintain that the only possible construal of the property of being knowable a priori that avoids invalidity is one that fails to generate the intended reductio. (shrink)

SummaryA familiar sort of argument for skepticism about the external world appeals to the evidential similarity between what is presumed to be the normal case and the case where one is a brain in a vat . An argument from Putnam has been taken by many to provide an a priori refutation of this sort of skeptical argument. The question I propose to address in this paper is whether Putnam's argument affords us an a priori refutation of skeptical (...) arguments that appeal to the claim that one does not know that one is not a BIV. I will develop a negative answer to this question along two related fronts. Along the first front I defend against new criticisms the common position that the externalism on which Putnam's argument is based entails skepticism about the meanings of sentences in our language and the contents of our thoughts. I do not take this to be a refutation of externalism or externalist arguments; rather, I see this as a motivation to locate the difficulty with arguments for externalism. But if externalism is abandoned, of course, the anti‐skeptical argument it has widely been taken to support must be abandoned along with it. I will argue, however, that this is not a significant loss, because along a second front I will argue that externalism cannot be given a priori justification; it is therefore ill‐suited to ground an a priori refutation of BIV skepticism anyway. (shrink)

SummaryA familiar sort of argument for skepticism about the external world appeals to the evidential similarity between what is presumed to be the normal case and the case where one is a brain in a vat. An argument from Putnam has been taken by many to provide an a priori refutation of this sort of skeptical argument. The question I propose to address in this paper is whether Putnam's argument affords us an a priori refutation of skeptical arguments (...) that appeal to the claim that one does not know that one is not a BIV. I will develop a negative answer to this question along two related fronts. Along the first front I defend against new criticisms the common position that the externalism on which Putnam's argument is based entails skepticism about the meanings of sentences in our language and the contents of our thoughts. I do not take this to be a refutation of externalism or externalist arguments; rather, I see this as a motivation to locate the difficulty with arguments for externalism. But if externalism is abandoned, of course, the anti‐skeptical argument it has widely been taken to support must be abandoned along with it. I will argue, however, that this is not a significant loss, because along a second front I will argue that externalism cannot be given a priori justification; it is therefore ill‐suited to ground an a priori refutation of BIV skepticism anyway. (shrink)

It has been argued that most truths about macroscopic states of affairs are entailed by a (hypothetical) complete descriptionPof the world in microscopic terms. In principle, micro-reductive explanations of non-microphysical truths could be constructeda priori.Against this claim, I show that reductive explanation requires knowledge about the phenomena to be reduced which cannot bea prioriextracted from microphysical information alone. Such reductions proceed in two steps: a “reductionR0” (“role-occupant”) establishes that a macroproperty M plays a certain causal role (specified in macro-terms), (...) while a “reductionMM” (“micro-macro”) establishes that some microproperty gives rise toM. (shrink)