Recent debates about thought experiments have focused on a perceived epistemological problem: how do thought experiments manage to provide knowledge when they yield no new empirical data? A bold answer to this question is provided by James Robert Brown’s platonisrn, according to which a certain class of thought experiments allow a sort of intellectual perception of laws of nature, understood as relations between universals. I suggest that there are three main problems with platonism. First, it is restricted to a very (...) small class of thought experiments; hence, it largely fails to address the general epistemological problem. Second, it is not quite clear what it is supposed to explain. Third, its explanatory value in any case seems dubious, since the mechanisms it postulates (i) appear to raise issues more ditficult than what they would explain, and (ii) seem to obviate the very need for conducting thought experiments. I also argue that it fails to give an accurate account of Brown’s flagship example, Galileo’s thought experiment on falling bodies. In conclusion, I suggest that although platonism about thought experiments is an exciting thesis, it is at present unconvincing. (shrink)

The traditional way of drawing the a priori/a posteriori distinction, bequeathed to us by Kant, leads to overestimating the role that experience plays in justifying ourbeliefs. There is an irony in this: though Kant was in the rationalist camp, his way of drawing the distinction gives an unfair advantage to radical empiricism. I offer an alternative way of drawing the distinction, one that does not bias the rationalist/empiricist debate.

It is commonly accepted by Kant scholars that Kant held that all necessary truths are a priori, and all a priori knowledge is knowledge of necessary truths. Against the prevailing interpretation, I argue that Kant was agnostic as to whether necessity and a priority are co-extensive. I focus on three kinds of modality Kant implicitly distinguishes: formal possibility and necessity, empirical possibility and necessity, and noumenal possibility and necessity. Formal possibility is compatibility with the forms of experience; empirical possibility is (...) compatibility with the causal powers of empirical objects; noumenal possibility is compatibility with the causal powers of things in themselves. Because we cannot know the causal powers of things in themselves, we cannot know what is noumenally necessary and what is noumenally contingent. Consequently, we cannot know whether noumenal necessity is co-extensive with a priority. Therefore, for all we know, some a priori propositions are noumenally contingent, and some a posteriori propositions are noumenally necessary. Thus, contrary to the received interpretation, Kant distinguishes epistemological from metaphysical modality. (shrink)

The notion of the a priori underwent several changes since the time it came into existence in the Middle Ages. Originally it had been used to mark a certain form of argument, an argument that proceeds from what is prior to what is later, from cause to effect: demonstratio procedens ex causis ad effectum = demonstratio a priori. But this changed with Kant, for whom it meant not a form of argument but rather some special kind of knowledge (or elements (...) thereof), namely knowledge that (a) is independent of particular experiences and (b) that makes experience in general (Erfahrung überhaupt) possible. Tied up with consciousness and the transcendental unity of apperception, Kant"s understanding of the a priori was in the spirit of his transcendental philosophy. But this understanding changed again with the rise of analytic philosophy, in which we still find the first characteristic but not the second anymore. The idea of Erfahrung überhaupt was given up, partly because one naturally wondered what exactly this notion of experience in general, or experience universally conceived, should be. Where should we get it from, if not by way of abstraction and generalization from individual cases of experience? And would this not make it an empirical concept, so that the whole project of asking for the conditions of its possibility would not lead us to the kind of certainty, necessity and universality we expect from a priori knowledge? There would be no guarantee that in the future we would not make discoveries that would give us new kinds of experiences or that would show us our experiences in a new light. Thus, we would have to admit that these experiences did not satisfy the conditions of experience we had set up originally. The a priori conditions would have to be revised. (shrink)

The classical view of the relationship between necessity and apriority, defended by Leibniz and Kant, is that all necessary truths are known a priori. The classical view is now almost universally rejected, ever since Saul Kripke and Hilary Putnam discovered that there are necessary truths that are known only a posteriori. However, in recent years a new debate has emerged over the epistemology of these necessary a posteriori truths. According to one view – call it the neo-classical view – knowledge (...) of a necessary truth always depends on at least one item of a priori knowledge. According to the rival view – call it the neoempiricist view – our knowledge of necessity is sometimes broadly empirical. In this paper I present and defend an argument against the neo-empiricist view. I argue that knowledge of the necessity of a necessary truth could not be broadly empirical. (shrink)

Scientific essentialism is the view that some necessities (e.g., water = H2O) can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism (e.g., twin earth intuitions) is reliable only if the intuitions required by philosophy to answer its central questions is (...) also reliable. Included is an outline of a modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition. (shrink)

Chalmers and Jackson (2001) offer an epistemic interpretation of the two-dimensional semantic framework advanced by Kaplan (1979, 1989), Stalnaker (1978), and others. Epistemic two-dimensional semantics (E2D) aims to re-forge the link between necessity and a priority seemingly broken by Kripke (1972/1980). On the E2D strategy, a priori knowledge of certain semantic intensions provides a route to a priori knowledge of a wide range of modal truths---nice outcome, if we can get it. E2D faces the serious challenge, however, that we typically (...) don't have even in-principle a priori access to the intensions at issue (Byrne and Pryor 2006, Melnyk 2001; see also Wilson 1982). As we substantiate, the "access-based challenge" to Chalmers and Jackson's version of E2D is successful; but the problem here isn't for E2D per se, but rather to E2D interpreted as appealing to a conceiving-based epistemology of intensions. Here we develop a version of E2D appealing to abduction rather than conceivability. We argue that abduction gives rise to beliefs that are reasonably taken to be a priori; and we show that E2D when combined with an abductive epistemology of intensions---that is, abductive two-dimensionalism---can successfully respond to the access-based challenge. We finish up with a case study, involving zombies and the mind-body problem, illustrating how the two versions of E2D may differ in application. (shrink)

Kripke has argued that definitions of units of measurements provide examples of statements that are both contingent and a priori. In this paper I argue that definitions of units of measurement are intended to be stipulations of what Kripke calls theoretical identities: a stipulation that two terms will have the same rigid designation. Hence such a definition is both a priori and necessary. The necessity arises because such definitions appeal to natural kind properties only, which on Kripke's account are necessary.

Kripke claims that there are necessary a posteriori truths and contingent a priori truths. These claims challenge the traditional Kantian view that (K) All knowledge of necessary truths is a priori and all a priori knowledge is of necessary truths. Kripke’s claims continue to be resisted, which indicates that the Kantian view remains attractive. My goal is to identify the most plausible principles linking the epistemic and the modal. My strategy for identifying the principles is to investigate two related questions. (...) Are there compelling general supporting arguments for (K)? Are there decisive counterexamples to (K)? My investigation uncovers two intuitively plausible principles that are not open to decisive counterexamples but which enjoy no compelling independent support. (shrink)

(1a) If Prince Albert Victor killed those people, he is Jack the Ripper (and Jack the Ripper killed those people). (1b) If Prince Albert Victor had killed those people, Jack the Ripper wouldn't have (and Prince Albert wouldn't have been Jack the Ripper).

It is widely believed that for all p, or at least for all entertainable p, it is knowable a priori that (p iff actually p). It is even more widely believed that for all such p, it is knowable that (p iff actually p). There is a simple argument against these claims from four antecedently plausible premises.

Why is two-dimensional semantics important? One can think of it as the most recent act in a drama involving three of the central concepts of philosophy: meaning, reason, and modality. First, Kant linked reason and modality, by suggesting that what is necessary is knowable a priori, and vice versa. Second, Frege linked reason and meaning, by proposing an aspect of meaning (sense) that is constitutively tied to cognitive signi?cance. Third, Carnap linked meaning and modality, by proposing an aspect of meaning (...) (intension) that is constitutively tied to possibility and necessity. (shrink)

The problem of nonreflectors perceived as colored is the central problem for Byrne & Hilbert's (B&H's) physicalism. Vision scientists and other interested parties need to consider the motivation for their account of “productance physicalism.” Is B&H's theory motivated by scientific concerns or by philosophical interests intended to preserve a physicalist account of color as a posteriori necessary?

I critically assess Stephen Yablo’s claim that cassinis are ovals is an a posteriori conceptual necessity. One does not know it simply by mastering the relevant concepts but by substantial empirical scrutiny. Yablo represents narrow content by would have turned out -conditionals. An epistemic reading of such conditionals does not bear Yablo’s claim. Two metaphysically laden readings are considered. In one reading, Yablo’s conditionals test under what circumstances concepts remain the same while their extensions diverge. As an alternative, I develop (...) a more literal metaphysical interpretation: Yablo’s conditionals draw on scenarios which are qualitatively identical to some original situation. None of these interpretations sustains Yablo’s core thesis. (shrink)

I defend a version of Kripke's claim that the metaphysically necessary and the knowable a priori are independent. On my version, there are two independent families of modal notions, metaphysical and epistemic, neither stronger than the other. Metaphysical possibility is constrained by the laws of nature. Logical validity, I suggest, is best understood in terms of epistemic necessity.

Two-dimensional semantics is a framework that helps us better understand some of the most fundamental issues in philosophy: those having to do with the relationship between the meaning of words, the way the world is, and our knowledge of the meaning of words. This selection of new essays by some of the world's leading authorities in this field sheds fresh light both on foundational issues regarding two-dimensional semantics and on its specific applications. Contributors: Richard Breheny, Alex Byrne, David Chalmers, Martin (...) Davies, Gareth Evans, Manuel Garcia-Carpintero, Josep Maci`, Martine Nida-Rumelin, Christopher Peacocke, James Pryor, Francois Recanati, Scott Soames, Cara Spencer, Robert Stalnaker, Kai-Yee Wong, Stephen Yablo. (shrink)

The thesis that the necessary and the a priori are extensionally equivalent consists of two independent claims: 1) All a priori truths are necessary and 2) all necessary truths are a priori. In Naming and Necessity1 Saul A. Kripke gives examples of necessary but a posteriori truths, so he disagrees with the second leg of the thesis.2 His examples are of two types; on the one hand statements involving essential properties and on the other hand true identity statements. My concern (...) will be with examples of the second type and whether they refute (2). (2), however, is ambiguous and can mean one of three things. (shrink)

In Naming and Necessity' Saul A. Kripke gives two types of examples of contingent truths knowable a priori. So he disagrees with the first leg of the thesis. As we will see later, his examples depend on the direct designation theory of names. While there have been attempts to provide examples of the contingent a priori that do not depend on that theory, most of those examples should be viewed as expansions, or modifications, of Kripke's examples. Philip Kitcher, for example, (...) gives an interesting example that has nothing to do with theories of names, but is produced using the indexical 'actual'.2 His example, however, is a variation of Kripke's Neptune Type example.' In what follows I will focus on Kripke's two types of examples and modifications of them. I will argue that although both types of example fail, it is possible to modify his Standard Metre example in such a way that we have an example of the contingent a priori. (shrink)

Recent work on the philosophy of modality has tended to pass over questions about iterated modalities in favour of constructing ambitious metaphysical theories of possibility and necessity, despite the central importance of iterated modalities to modal logic. Yet there are numerous unresolved but fundamental issues involving iterated modalities: Chandler and Salmon have provided forceful arguments against the widespread assumption that all necessary truths are necessarily necessary, for example. The current paper examines a range of ways in which one might seek (...) to identify limited regions within which some of the most well-known principles featuring iterated modalities may safely be assumed. (shrink)

It is generally assumed that rigidity plays a key role in explaining the necessary a posteriori status of identity statements, both between proper names and between natural kind terms. However, while the notion of rigid designation is well defined for singular terms, there is no generally accepted definition of what it is for a general term to be rigid. In this paper I argue that the most common view, according to which rigid general terms are the ones which designate the (...) same kind in all possible worlds, fails to deliver a posteriori necessities. I also present an alternative view, on which the work of explaining a posteriori necessities is not done by rigidity, but by a related metasemantic notion, which I call actuality - dependence. (shrink)

The New Semantics (NS) introduced by Kripke and Putnam is often thought to block antiphysicalist arguments that involve an inference from an explanatory gap to a failure of supervenience. But this “NS Rebuttal” depends upon two assumptions that are shown to be dubious. First, it assumes that mental-kind terms are among the kinds of terms to which NS analysis is properly applied. However, there are important differences in this regard between the behavior of notions like ‘pain’ and notions like ‘water’, (...) as Kripke himself has argued. Second, even on the assumption that NS analysis is appropriate to mental-kind terms, it is further assumed that this would block the anti-physicalist premise that an abiding and principled explanatory gap would entail a failure of metaphysical supervenience. But the paradigm examples of NS analysis show nothing of the sort. What they show is that there are a posteriori necessities (e.g., “water contains hydrogen”) that cannot be inferred from the sense of natural kind terms. But they do not show that such necessities cannot be derived from an adequate scientific understanding of the phenomena in question. Indeed, such derivations are often available with kinds like water, but seem unavailable with mental kinds like ‘pain’ and ‘belief’. (shrink)

Kant famously argued that, from experience, we can only learn how something actually is, but not that it must be so. In this paper, I defend an improved version of Kant's argument for the existence of a priori knowledge, the Modal Argument , against recent objections by Casullo and Kitcher. For the sake of the argument, I concede Casullo's claim that we may know certain counterfactuals in an empirical way and thereby gain epistemic access to some nearby, nomologically possible worlds. (...) But I maintain that our beliefs about metaphysical necessities still cannot be justified empirically. Furthermore, I reject Casullo's deflationary thesis about the significance of such justification. Kitcher's most troublesome objection is that we can gain any modal justification whatsoever through testimony , i.e. in an experiential way. This can be countered by distinguishing between productive sources of justification, like perception, and merely reproductive sources, like testimony. Thus, some productive a priori source will always be needed somewhere. 1. (shrink)

Kripke maintains that one who stipulatively introduces the term ‘one meter’ as a rigid designator for the length of a certain stick s at time t is in a position to know a priori that if s exists at t then the length of s at t is one meter. Some (e.g., Soames 2003) have objected to this alleged instance of the contingent a priori on the grounds that the stipulator's knowledge would have to be based in part on substantive (...) metalinguistic knowledge. I examine Soames's argument for the a posteriority of the relevant metalinguistic knowledge, and I argue that its main premise is false. (shrink)

Kripke maintains that one who stipulatively introduces the term ‘one meter’ as a rigid designator for the length of a certain stick s at time t is in a position to know a priori that if s exists at t then the length of s at t is one meter. Some (e.g., Soames 2003) have objected to this alleged instance of the contingent a priori on the grounds that the stipulator's knowledge would have to be based in part on substantive (...) metalinguistic knowledge. I examine Soames's argument for the a posteriority of the relevant metalinguistic knowledge, and I argue that its main premise is false. (shrink)

Williamson (1986) presents a troublesome example of the contingent a priori ; troublesome, because it does not involve indexicals, and hence cannot be defused via the usual two-dimensional strategies. Here I explore how the example works, via an examination of crucial belief-forming method M, partly in response to Hawthorne (2002) and the questions there raised for 'hyperreliable' belief-forming methods. I suggest that, when used to form a belief, M does its special work through creating a verifying state of affairs which (...) guarantees the truth of the belief thus formed. This creative link can be said to account for the knowledge-conferring status of M. But it also provides us with a way to defuse the purported example of the contingent a priori . The knowledge at issue is only a priori in virtue of this creative link, an importantly different epistemic achievement from standard cases of a priori knowledge. One important moral to be drawn is that the a priori / a posteriori distinction does not appear to be slicing the epistemological beast at its joints. (shrink)

Indexicals are linguistic expressions whose meaning remain stable while their reference shifts from utterance to utterance. Paradigmatic cases in English are ‘I’, ‘here’, and ‘now’. Recently, a number of authors have argued that various constructions in our language harbor hidden indexicals. We say ’hidden’ because these indexicals are unpronounced, even though they are alleged to be real linguistic components. Constructions taken by some authors to be associated, or to ‘co-habit’, with hidden indexicals include: definite descriptions and quantifiers more generally (hidden (...) indexical refers to a domain – Davies (1981), Westerstahl (1985), Soames (1986), Higginbotham (1988), Stanley and Williamson (1995)), propositional attitude verbs (hidden indexical refers to a mode of presentation – Richard (1990)), comparative adjectives (hidden indexical refers to comparison classes – Partee (1989), Kamp (1975), Ludlow (1989)). An interesting recent addition is the view that all nouns are associated with a hidden indexical referring to a domain restriction (Stanley and Szabo (2000), Stanley (2002)). (shrink)

This article critically examines Saul Kripke's (1972) argument for the separability of necessary truths from truths known a priori, focusing on his criticism of the standard meter case presented by Wittgenstein (1968). It attempts to show that Kripke's argument is unworkable on any of several readings. Wittgenstein's own broadly conventionalist account of necessary truth is then considered in the light of the standard meter example.

Particularism renders the options for a sound moral epistemology few and the prospects dim. One leading approach treats basic knowledge of particular cases as derivable from an a priori moral principle and a posteriori knowledge of the contingent non-moral facts to which the principle applies. Particularists must forgo this approach because it requires principles. Yet a purely a posteriori moral epistemology is also implausible, especially when combined with particularism. Particularists such as Jonathan Dancy are thus led to the view that (...) our basic moral knowledge is a priori knowledge of contingent moral facts. We argue that this epistemology is unsound. While some cases of a priori knowledge of (even deeply) contingent facts may be defensible, they are not sufficient for particularist purposes. Moreover, neither Dancy’s appeal to the distinction between positive and negative dependence nor his discussion of intuitive examples provides sufficient support for this epistemology. (shrink)

Inspired by two-dimensional modal logic, some have sought to provide analyses of the notion of the contingent a priori which identify the a priori with truths which have a necessary diagonal. I argue that these analyses fail insofar as they miss the crucial epistemic aspect of the a priori. Augmenting these analyses with specifically epistemic accounts might be possible, but the interest would then reside in these epistemic accounts of the a priori and not in the formal models.

Chalmers argues that zombies are possible and that therefore consciousness does not supervene on physical facts, which shows the falsity of materialism. The crucial step in this argument – that zombies are possible – follows from their conceivability and hence depends on assuming that conceivability implies possibility. But while Chalmers’s defense of this assumption – call it the conceivability principle – is the key part of his argument, it has not been well understood. As I see it, Chalmers’s defense of (...) the conceivability principle comes in his response to the so-called objection from a posteriori necessity. The defense aims at showing that there is no gap between conceivability and possibility since no such gap can be generated by necessary a posteriori truths. I will argue that while Chalmers is right to the extent that there is no gap between conceivability and possibility within the standard Kripkean model of a posteriori necessity, his general conclusion is not justified. This is because the conceivability principle might be inconsistent with a posteriori necessity understood in some non-Kripkean way and Chalmers has not shown that no such alternative understanding of a posteriori necessity is available. (shrink)

Moderate rationalists maintain that our rational intuitions provide us with prima facie justification for believing various necessary propositions. Such a claim is often criticized on the grounds that our having reliable rational intuitions about domains in which the truths are necessary is inexplicable in some epistemically objectionable sense. In this paper, I defend moderate rationalism against such criticism. I argue that if the reliability of our rational intuitions is taken to be contingent, then there is no reason to think that (...) our reliability is inexplicable. I also suggest that our reliability is, in fact, necessary, and that such necessary reliability neither admits of, nor requires, any explanation of the envisaged sort. (shrink)

write to correct errors in Christopher Pincock’s review of my discussion of IRussell. First, according to Pincock, I attempt to “undermine Moore’s views on ethics in Part One, [and] Russell’s conception of analysis in Part Two” by charging them with a pre-Kripkean conflation of necessity with apriority and analyticity. Not so. Although I do show that such conflation had negative consequences for the views of several philosophers, Moore and Russell are not among them. Moore’s error—which marred the defence of his (...) thesis that conclusions about goodness are never consequences of purely descriptive premisses—was in tacitly assuming that all necessary/a priori relations among concepts arise from definitions (see my : –). A similar problem occurs in Russell, but only tangentially in connection with one possible route to his problematic principle () in Our Knowledge of the External World, the critique of which was not as part of any attack on his general conception of analysis (. (shrink)

One of Kripke's fundamental objections to descriptivism was that the theory misclassifies certain _a posteriori_ propositions expressed by sentences involving names as _a priori_. Though nowadays very few philosophers would endorse a descriptivism of the sort that Kripke criticized, many find two-dimensional semantics attractive as a kind of successor theory. Because two-dimensionalism needn't be a form of descriptivism, it is not open to the epistemic argument as formulated by Kripke; but the most promising versions of two-dimensionalism are open to a (...) close relative of that argument. (shrink)

Since Saul Kripke’s Naming and Necessity, the view that there are contingent apriori truths has been surprisingly widespread. In this paper, I argue against that view. My first point is that in general, occurrences of predicates “a priori” and “contingent” are implicitly relativized to some circumstance, involving an agent, a time, a location. My second point is that apriority and necessity coineide when relativized to the same circumstance. That is to say, what is known apriori (by an agent in a (...) circumstance) cannot fail to be the case (in the same circumstance), hence it is necessary. (shrink)

By introducing a name 'one meter' and stipulating that it refers to the length of stick S, the stipulator appears to be in a position to gain immediate (and arguably a priori) knowledge of a mind- and language-independent fact-the fact that the length of stick S is one meter. It appears that other users of the name can gain this knowledge only through empirical enquiry. I argue that this presents a paradox. After clarifying the nature of the paradox, I offer (...) a solution by arguing that, contrary to appearances, other users of 'one meter' implicitly knew that the length of stick S is one meter before learning the name, as did the stipulator prior to introducing the name. There is some distinct knowledge that other users of the name can only gain empirically, but the stipulator cannot gain this knowledge without empirical enquiry either. (shrink)

THE PAPER BEGINS BY CONSIDERING THREE ALTERNATIVE DEFINITIONS OF "ANALYTIC," ONE IN TERMS OF LOGICAL TRUTH, ONE IN TERMS OF THE MEANINGS OF WORDS, AND ONE IN TERMS OF SELF-CONTRADICTION OR INCOHERENCE. NEXT, FIVE DEFINITIONS OF "NECESSARY" ARE CONSIDERED, ONE IN TERMS OF ANALYTICITY, AND ONE PICKING OUT THE BROADER KIND OF LOGICAL NECESSITY DISCUSSED BY KRIPKE AND PLANTINGA. FINALLY, THREE DEFINITIONS OF "A PRIORI" ARE CONSIDERED. ONLY ON A FEW OF THESE DEFINITIONS DO THE CATEGORIES OF ANALYTIC, NECESSARY, AND (...) A PRIORI COINCIDE. (shrink)

Two sentences express the same proposition if they are synonymous; they express the same statement if they attribute the same properties to the same objects at the same time (however objects and times are picked out). Neither propositions nor statements are necessary a posteriori. Suggested examples of the necessary a posteriori, such as "Hesperus is Phosphorus", or "water is H2O", only appear to be such because of a confusion between proposition and statement.

The distinction between a priori and a posteriori knowledge has been the subject of an enormous amount of discussion, but the literature is biased against recognizing the intimate relationship between these forms of knowledge. For instance, it seems to be almost impossible to find a sample of pure a priori or a posteriori knowledge. In this paper, it will be suggested that distinguishing between a priori and a posteriori is more problematic than is often suggested, and that a priori and (...) a posteriori resources are in fact used in parallel. We will define this relationship between a priori and a posteriori knowledge as the bootstrapping relationship. As we will see, this relationship gives us reasons to seek for an altogether novel definition of a priori and a posteriori knowledge. Specifically, we will have to analyse the relationship between a priori knowledge and a priori reasoning , and it will be suggested that the latter serves as a more promising starting point for the analysis of aprioricity. We will also analyse a number of examples from the natural sciences and consider the role of a priori reasoning in these examples. The focus of this paper is the analysis of the concepts of a priori and a posteriori knowledge rather than the epistemic domain of a posteriori and a priori justification. (shrink)

This paper challenges the Kripkean interpretation of a posteriori necessities. It will be demonstrated, by an analysis of classic examples, that the modal content of supposed a posteriori necessities is more complicated than the Kripkean line suggests. We will see that further research is needed concerning the a priori principles underlying all a posteriori necessities. In the course of this analysis it will emerge that the modal content of a posteriori necessities can be best described in terms of a Finean (...) conception of modality – by giving essences priority over modality. The upshot of this is that we might be able to establish the necessity of certain supposed a posteriori necessities by a priori means. (shrink)

In this paper I will offer a novel understanding of a priori knowledge. My claim is that the sharp distinction that is usually made between a priori and a posteriori knowledge is groundless. It will be argued that a plausible understanding of a priori and a posteriori knowledge has to acknowledge that they are in a constant bootstrapping relationship. It is also crucial that we distinguish between a priori propositions that hold in the actual world and merely possible, non-actual a (...) priori propositions, as we will see when considering cases like Euclidean geometry. Furthermore, contrary to what Kripke seems to suggest, a priori knowledge is intimately connected with metaphysical modality, indeed, grounded in it. The task of a priori reasoning, according to this account, is to delimit the space of metaphysically possible worlds in order for us to be able to determine what is actual. (shrink)

I undertake a metaphysical investigation of Saul Kripke's modern classic, Naming and Necessity (1980). The general problem of my study may be expressed as follows: What is the metaphysical justification of the validity and existence of the pertinent classes of truths, the necessary a posteriori and the contingent a priori, according to the Kripke Paradigm? My approach is meant to disclose the logical and ontological principles underlying Kripke's arguments for the necessary a posteriori and the contingent a priori respectively. The (...) results of my study are to a certain extent negative: They attempt to show that the classes of the necessary a posteriori and the contingent a priori statements cannot possibly be valid. If the general argument of this thesis is sound, then, on this ground, the realist conception of metaphysical essentialism is rejected. The positive thesis of this study is the articulation of certain ways to frame the necessary a posteriori and the contingent a priori which avoid the problems of realistic essentialism and which suggest a certain transcendental reading of modality. According to the Kripke Paradigm, any de dicto modal status (of a statement) derives ultimately from the de re modality inherent in the object designated, as the object is characterised by contingent and necessary properties on the ontological level. Thus, the Kripke Paradigm is primarily a thesis in de re realist essentialism. The final verdict in this study is that the Kripke Paradigm cannot sustain the realistic conception of de re metaphysical essentialism. If we should adopt a transcendental reading of modality, then certain portions of the Kripke Paradigm are valid. I do not delineate or possess the details of a comprehensive doctrine of transcendental metaphysic. Nevertheless, the observations I make should suffice to bring about the rough orientation of how I conceive the notion of transcendental modality. (shrink)

I argue that you can have a priori knowledge of propositions that neither are nor appear necessarily true. You can know a priori contingent propositions that you recognize as such. This overturns a standard view in contemporary epistemology and the traditional view of the a priori, which restrict a priori knowledge to necessary truths, or at least to truths that appear necessary.

Against Norton's claim that all thought experiments can be reduced to explicit arguments, I defend Brown's position that certain thought experiments yield a priori knowledge. They do this, I argue, not by allowing us to perceive “Platonic universals” (Brown), even though they may contain non-propositional components that are epistemically indispensable, but by helping to identify certain tacit presuppositions or “natural interpretations” (Feyerabend's term) that lead to a contradiction when the phenomenon is described in terms of them, and by suggesting a (...) new natural interpretation in terms of which the phenomenon can be redescribed free of contradiction. (shrink)

Hans Reichenbach introduced two seemingly separate sets of distinctions in his epistemology at different times. One is between the axioms of coordination and the axioms of connections . The other distinction is between the context of discovery and the context of justification . The status and nature of each of these distinctions have been subject-matter of an ongoing debate among philosophers of science. Thus, there is a significant amount of works considering both distinctions separately. However, the relevance of Reichenbach’s two (...) distinctions to each other does not seem to have enjoyed the same amount of interest so far. This is what I would like to consider in this paper. In other words, I am concerned with the question: what kind of relationship is there between his two distinctions, if there is any? (shrink)

In this article I investigate a neglected form of radical skepticism that questions whether any of our logical, mathematical and other seemingly self-evident beliefs count as knowledge. ‘A priori skepticism,’ as I will call it, challenges our ability to know any of the following sorts of propositions: (1.1) The sum of two and three is five. (1.2) Whatever is square is rectangular. (1.3) Whatever is red is colored. (1.4) No surface can be uniformly red and uniformly blue at the same (...) time. (1.5) If ‘if p then q’ is true and ‘p’ is true, then ‘q’ is true. (1.6) No statement can be both true and false at the same time and in the same respect. (1.7) If A is taller than B, and B is taller than C, then A is taller than C. (1.8) Everything is identical to itself. (1.9) If the conclusion of an inductive argument is contingent, it is possible for the premises of that argument to be true and its conclusion to be false. (1.10) George W. Bush could have been a plumber. (1.11) George W. Bush could not have been a prime number. (1.12) ‘2 + 3 = 5’ is necessarily true. (shrink)

I reconstruct and critique two arguments Laurence BonJour has recently offered against skepticism about the a priori. While the arguments may provide anti-skeptical, internalist foundationalists with reason to accept the a priori, I show that neither argument provides sufficient reason for believing the more general conclusion that there is no rational alternative to accepting the a priori.

A stellar line-up of leading philosophers from around the world offer new treatments of a topic which has long been central to philosophical debate, and in which there has recently been a surge of interest. The a priori is the category of knowledge that is supposed to be independent of experience. The contributors offer a variety of approaches to the a priori and examine its role in different areas of philosophical inquiry. The editors' introduction offers an ideal way into the (...) discussions. (shrink)

A stellar line-up of leading philosophers from around the world offer new treatments of a topic which has long been central to philosophical debate, and in ...

A comprehensive defence of the rationalist view that insight independent of experience is a genuine basis for knowledge.

The view that logic is true independently of a subject matter is criticized—enlarging on Quine's criticisms and adding further ones. It is then argued apriori that full reflective understanding of logic and deductive reasoning requires substantial commitment to mathematical entities. It is emphasized that the objectively apriori connections between deductive reasoning and commitment to mathematics need not be accepted by or even comprehensible to a given deductive reasoner. The relevant connections emerged only slowly in the history of logic. But they (...) can be recognized retrospectively as implicit in logic and deductive reasoning. The paper concludes with discussion of the relevance of its main argument to Kant's question—how is apriori knowledge of a subject matter possible? (shrink)

This paper deals with the question whether existence claims may be supported in an a priori manner. I examine a particular case in point, namely the argument for the existence of so-called logical atoms to be found in Wittgenstein's Tractatus. Although I find it wanting, I argue that more general reflections on the notion of existence allow us to straightforwardly answer our initial question in the affirmative.