The past twenty-five years have seen a major renewal of interest in the topic of a priori knowledge. In the sixteen essays collected here, which span this entire period, philosopher Albert Casullo documents the complex set of issues motivating the renewed interest, identifies the central epistemological questions, and provides the leading ideas of a unified response to them.

This book answers three questions: (i) What is it for a statement to be analytically true? (ii) What is a priori knowledge? (How does it differ from inherited empirical knowledge? And how does it differ from acquired conceptual (non-empirical) knowledge, such as one's knowledge that not all continuous functions are differentiable?). (iii) Do we have a priori knowledge? It is shown that content-externalism is an 'epistemologicization' of the (logically, not psychologically) innocuous fact that, (...) if a sentence S of natural language expresses a multiply quantified generalization, S also expresses each quantified generalization obtained by permuting the quantifiers in it. It is also shown that, through judicious usage of Kaplan's dthat-operator, the shred of truth in content externalism can be reconciled with the datum that, in virtue of having a given representational content R, a mental state M has causal powers that it would not otherwise have. And it is thereby shown how to reconcile content-externalism, so far as the latter is true, with the legitimacy of individualist approaches to psychology. Finally, it is shown that content-externalism embodies a crude and false conception of the nature of the relationship between the literal meanings of linguistic expressions, on the one hand, and, on the other hand, the contents of the thoughts underlying our usage of such expressions. More precisely, content-externalism presupposes that literal meaning and cognitive content are in lockstep with each other; which, it is shown, is not the case and---what is also shown---only appears to be the case because of a failure on the part of semanticists to know where to draw the line between semantics and pragmatics. (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.

This paper provides a defense of two traditional theses: the Autonomy of Philosophy and the Authority of Philosophy. The first step is a defense of the evidential status of intuitions (intellectual seemings). Rival views (such as radical empiricism), which reject the evidential status of intuitions, are shown to be epistemically self-defeating. It is then argued that the only way to explain the evidential status of intuitions is to invoke modal reliabilism. This theory requires that intuitions have a certain qualified modal (...) tie to the truth. This result is then used as the basis of the defense of the Autonomy and Authority theses. The paper closes with a defense of the two theses against a potential threat from scientific essentialism. (shrink)

Many philosophers are again examining the traditional topic of a priori knowledge, or knowledge that does not depend on sensory experience. This volume collects the most important recent essays on the subject by well-known thinkers such as A.J. Ayer, W.V. Quine, Barry Stroud, C.I. Lewis, Hilary Putnam, Roderick M. Chisholm, Saul A. Kripke, Albert Casullo, R.G. Swinburne, and Philip Kitcher. Including an introduction by the editor and an extensive bibliography, this book provides philosophers and students with an (...) in-depth look at contemporary investigations into the nature of a priori knowledge. (shrink)

a priori. Since I ended up defending an unpopular answer to this question—"No"—it’s hardly surprising that people have scrutinized the account, or that many have concluded that I stacked the deck in the first place. Of course, this was not my view of the matter. My own judgment was that I’d uncovered the tacit commitments of mathematical apriorists and that the widespread acceptance of mathematical apriorism rested on failure to ask what was needed for knowledge to be a (...) priori . Nevertheless, my critics have raised important challenges, and have offered rival conceptions that are less demanding. I want to examine their objections to my explication of a priori knowledge, and to explore whether the weaker alternatives succeed in preserving traditional philosophical claims. What follows is a mixture of penitence and intransigence. (shrink)

This article considers an apparent Achilles heel for Kant’s transcendental idealism, concerning his account of how synthetic a priori knowledge is possible. The problem is that while Kant’s distinctive attempt to explain synthetic a priori knowledge lies at the heart of his transcendental idealism, this explanation appears to face a dilemma: either the explanation generates a problematic regress, or the explanation it offers gives us no reason to favour transcendental idealism over transcendental realism. In the article, (...) I consider G. E. Moore’s version of the problem, which I argue has not yet received an adequate response. Instead, I offer a way out of this dilemma by focusing on the normativity rather than the metaphysics of the mind. (shrink)

The idea that the epistemology of modality is in some sense a priori is a popular one, but it has turned out to be difficult to precisify in a way that does not expose it to decisive counterexamples. The most common precisifications follow Kripke’s suggestion that cases of necessary a posteriori truth that can be known a priori to be necessary if true ‘may give a clue to a general characterization of a posteriori knowledge of necessary truths’. (...) The idea is that whether it is contingent whether p can be known a priori for at least some broad range of sentences ‘p’. Recently, Al Casullo and Jens Kipper have discussed restrictions of such principles to atomic sentences. We show that decisive counterexamples even to such dramatically restricted Kripke-style principles can be constructed using minimal logical resources. We then consider further restrictions, and show that the counterexamples to the original principles can be turned into counterexamples to the further restricted principles. We conclude that, if there are any true restrictions of Kripke-style principles, then they are so weak as to be of little epistemological interest. (shrink)

This is the second in a two part series of articles that attempt to clarify the nature and enduring relevance of Kant's concept of a priori knowledge. (For Part I, see below.) In this article I focus mainly on Saul Kripke's critique of Kant, in Naming and Necessity. I argue that Kripke draws attention to a genuine defect in Kant's epistemological framework, but that he used definitions of certain key terms that were quite different from Kant's definitions. When (...) Kripke's definitions are replaced by Kant's definitions, Kripke's account of the status of naming turns out to be a defense of analytic aposteriority as a significant classification of knowledge that Kant neglected. I also introduce here a new way of understanding such epistemological labels, as defining the perspective adopted by the knowing subject in a given situation, rather than an objective characteristic of certain propositions as such. (shrink)

There are four approaches to analyzing the concept of a priori knowledge. The primary target of the reductive approach is the concept of a priori justification. The primary target of the nonreductive approach is the concept of a priori knowledge. There are two approaches to analyzing each primary target. A theory-neutral approach provides an analysis that does not presuppose any general theory of knowledge or justification. A theory-laden approach provides an analysis that does presuppose (...) some general theory of knowledge or justification. Those who embrace a theory-laden analysis incur a special burden: they must separate the features of their analysis that are constitutive of the a priori from those that are constitutive of the background theory. My goal is to illustrate how the failure to separate these features leads to erroneous conclusions about the nature of a priori knowledge. (shrink)

This paper contains replies to comments on the author's paper "A Priori Knowledge and the Scope of Philosophy." Several points in the argument of that paper are given further clarification: the notion of our standard justificatory procedure, the notion of a basic source of evidence, and the doctrine of modal reliabilism. The reliability of intuition is then defended against Lycan's skepticism and a response is given to Lycan's claim that the scope of a priori knowledge does (...) not include philosophically central topics such as the nature of consciousness. Next a counterfactual account of intuitions proposed by Sosa is criticized. Finally, in response to certain questions raised by Sosa, the explanation of the evidential status of intuition offered in the original paper receives further elaboration. (shrink)

This paper is aimed at understanding one central aspect of Bolzano's views on deductive knowledge: what it means for a proposition and for a term to be known a priori. I argue that, for Bolzano, a priori knowledge is knowledge by virtue of meaning and that Bolzano has substantial views about meaning and what it is to know the latter. In particular, Bolzano believes that meaning is determined by implicit definition, i.e. the fundamental propositions in (...) a deductive system. I go into some detail in presenting and discussing Bolzano's views on grounding, a priori knowledge and implicit definition. I explain why other aspects of Bolzano's theory and, in particular, his peculiar understanding of analyticity and the related notion of Ableitbarkeit might, as it has invariably in the past, mislead one to believe that Bolzano lacks a significant account oï a priori knowledge. Throughout the paper, I point out to the ways in which, in this respect, Bolzano's antagonistic relationship to Kant directly shaped his own views. (shrink)

forthcoming in Philosophy Compass. This is a paper which aims both to survey the field and do some work at its cutting edge.

The argument is not, however, problem-free. First: while the meaning of s might not guarantee a verifying state of affairs, mightn’t the fact of one’s believing that s is true guarantee a verifying state of affairs? And mightn’t this fact be exploited to secure knowledge of truths that are deeply contingent? Second: the argument seems to rely on the principle that if I can conceive that not P is actually the case, then I do not know that P. But (...) it is generally agreed that a knowledge-conferring warrant for some P need not offer a watertight guarantee of P and thus need not render it inconceivable that the actual world falsifies P. Why then require such a guarantee when it comes to priori warrant? The first objection is that a guarantee of truth need not come from semantics. The second is that no such guarantee is required for a priori knowledge. I shall be exploring both of these ideas in what follows. (shrink)

I exist. That is something I know. Most philosophers think that Descartes was right that each of us knows that we exist. Furthermore most philosophers agree with Descartes that there is something special about how we know it. Agreement ends there. There is little agreement about exactly what is special about this knowledge. I shall present an account that is in some respects Cartesian in spirit, although I shall not pursue interpretive questions very far. On this account, I know (...) that I exist a priori; and I shall advance an explanation of how this a priori knowledge is possible and actual. I then consider the question of whether the belief that I exist is justified and, if so, how. I argue that the situation is different in important ways from the knowledge that I exist. (shrink)

The past twenty-five years have seen a major renewal of interest in the topic of a priori knowledge. In the sixteen essays collected here, which span this entire period, philosopher Albert Casullo documents the complex set of issues motivating the renewed interest, identifies the central epistemological questions, and provides the leading ideas of a unified response to them.

This article is mainly a critique of Philip Kitcher's book, The Nature of Mathematical Knowledge. Four weaknesses in Kitcher's objection to Kant arise out of Kitcher's failure to recognize the perspectival nature of Kant's position. A proper understanding of Kant's theory of mathematics requires awareness of the perspectival nuances implicit in Kant's theory of pure intuition.

This paper examines popular‘conventionalist’explanations of why philosophers need not back up their claims about how‘we’use our words with empirical studies of actual usage. It argues that such explanations are incompatible with a number of currently popular and plausible assumptions about language's ‘social’character. Alternate explanations of the philosopher's purported entitlement to make a priori claims about‘our’usage are then suggested. While these alternate explanations would, unlike the conventionalist ones, be compatible with the more social picture of language, they are each shown (...) to face serious problems of their own. (shrink)

The prevailing interpretation of Kant’s _First Critique _in Anglo-American philosophy views his theory of a priori knowledge as basically a theory about the possibility of empirical knowledge, or the a priori conditions for that possibility. Instead, Robert Greenberg argues that Kant is more fundamentally concerned with the possibility of a priori knowledge—the very possibility of the possibility of empirical knowledge in the first place. Greenberg advances four central theses: the _Critique_ is primarily concerned (...) about the possibility, or relation to objects, of a priori_,_ not empirical knowledge, and Kant’s theory of that possibility is defensible; Kant’s transcendental ontology must be distinct from the conditions of the possibility of a priori knowledge; the functions of judgment, in Kant’s discussion of the Table of Judgments, should be seen according to his transcendental logic as having content, not as being just logical forms of judgment making; Kant’s distinction between and connection of ordering relations and reference relations have to be kept in mind to avoid misunderstanding the _Critique_. At every step of the way Greenberg contrasts his view with the major interpretations of Kant by commentators like Henry Allison, Jonathan Bennett, Paul Guyer, and Peter Strawson. Not only does this new approach to Kant present a strong challenge to these dominant interpretations, but by being more true to Kant’s own intent it holds promise for making better sense out of what have been seen as the _First Critique_’s discordant themes. (shrink)

In this article, I discuss Hawthorne'€™s contextualist solution to Benacerraf'€™s dilemma. He wants to find a satisfactory epistemology to go with realist ontology, namely with causally inaccessible mathematical and modal entities. I claim that he is unsuccessful. The contextualist theories of knowledge attributions were primarily developed as a response to the skeptical argument based on the deductive closure principle. Hawthorne uses the same strategy in his attempt to solve the epistemologist puzzle facing the proponents of mathematical and modal realism, (...) but this problem is of a different nature than the skeptical one. The contextualist theory of knowledge attributions cannot help us with the question about the nature of mathematical and modal reality and how they can be known. I further argue that Hawthorne'€™s account does not say anything about a priori status of mathematical and modal knowledge. Later, Hawthorne adds to his account an implausible claim that in some contexts a gettierized belief counts as knowledge. (shrink)

The argument is not, however, problem-free. First: while the meaning of s might not guarantee a verifying state of affairs, mightn’t the fact of one’s believing that s is true guarantee a verifying state of affairs? And mightn’t this fact be exploited to secure knowledge of truths that are deeply contingent? Second: the argument seems to rely on the principle that if I can conceive that not P is actually the case, then I do not know that P. But (...) it is generally agreed that a knowledge-conferring warrant for some P need not offer a watertight guarantee of P and thus need not render it inconceivable that the actual world falsifies P. Why then require such a guarantee when it comes to priori warrant? The first objection is that a guarantee of truth need not come from semantics. The second is that no such guarantee is required for a priori knowledge. I shall be exploring both of these ideas in what follows. (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)

The argument is not, however, problem-free. First: while the meaning of s might not guarantee a verifying state of affairs, mightn’t the fact of one’s believing that s is true guarantee a verifying state of affairs? And mightn’t this fact be exploited to secure knowledge of truths that are deeply contingent? Second: the argument seems to rely on the principle that if I can conceive that not P is actually the case, then I do not know that P. But (...) it is generally agreed that a knowledge-conferring warrant for some P need not offer a watertight guarantee of P and thus need not render it inconceivable that the actual world falsifies P. Why then require such a guarantee when it comes to priori warrant? The first objection is that a guarantee of truth need not come from semantics. The second is that no such guarantee is required for a priori knowledge. I shall be exploring both of these ideas in what follows. (shrink)

The book sets out to analyse the notion of a priori justification and of a priori knowledge.

Recent defenses of a priori knowledge can be applied to the idea of conventions in science in order to indicate one important sense in which conventionalism is correctsome elements of physical theory have a unique epistemological status as a functionally a priori part of our physical theory. I will argue that the former a priori should be treated as empirical in a very abstract sense, but still conventional. Though actually coming closer to the Quinean position than (...) recent defenses of a priori knowledge, the picture of science developed here is very different from that developed in Quinean holism in that categories of knowledge can be differentiated. (shrink)

This paper is a condensed version of the author’s “A Theory of the A Priori” (Pacific Philosophical Quarterly, 2000) for the evidential status of intuitions, the incoherence of radical empiricism. the thesis of modal reliabilism, and the Autonomy of Philosophy Thesis (according to which the a priori disciplines are autonomous from empirical science).

Suppose a sentence of the following form is true in a certain context: ‘Necessarily, whenever one believes that the F is uniquely F if anything is, and x is the F, one believes that x is uniquely F if anything is’. I argue that almost always, in such a case, the sentences that result when both occurrences of ‘believes’ are replaced with ‘has justification to believe’, ‘knows’, or ‘knows a priori’ will also be true in the same context. I (...) also argue that many sentences of the relevant form are true in ordinary contexts, and conclude that a priori knowledge of contingent de re propositions is a common and unmysterious phenomenon. However, because of the pervasive context-sensitivity of propositional attitude ascriptions, the question what it is possible to know a priori concerning a given object will have very different answers in different contexts. (shrink)

In the First Chapter, I give an interpretation of Kant's characterization of a priori knowledge which sharply distinguishes Kant's from an innatist conception; in this way, I distinguish Kant's transcendental explanation of a prioricity from both innatist and naturalistic explanations. ;The arguments given by Kant to support his claim that we are in fact in possession of a priori knowledge rely on his criterion of a prioricity: if a truth is necessary then it must be justified (...) a priori. I criticize the criterion's failure to account for actual cases of being justified in believing necessary truths. Finally, I discuss whether Kant has arguments to show that there is a priori knowledge which are independent of the criterion. ;In the Second Chapter, I examine the similarities and differences between Kant's and Frege's conceptions of a priori knowledge. I argue that Frege, like Kant, concentrates exclusively on the ways we must justify our beliefs in certain truths . I show, however, that Frege does not have straightforward arguments to prove that we can and do know a priori any arithmetical or logical truths, and that he does not have any straightforward explanation of the a prioricity of the laws of logic. Finally, I argue that even though a priori items of knowledge play a privileged role in Frege's project, this role differs from the one that such items have in a Kantian-transcendental project. ;In the Third Chapter, I explore whether we can make sense of the notion of a prioricity and prove that there is a priori knowledge by adopting an approach to justification which differs from both Kant's and Frege's. This approach does not concentrate on the ways we must be justified, but on the actual ways we justify our beliefs. I argue that this approach faces enormous difficulties regarding a prioricity. The central difficulty is that the actual complete justification for a belief cannot be captured exclusively in propositional terms. If a belief is based on inference, practical abilities, tendencies or dispositions enter in its justification. . . . UMI. (shrink)

I look at incompatibilist arguments aimed at showing that the conjunction of the thesis that a subject has privileged, a priori access to the contents of her own thoughts, on the one hand, and of semantic externalism, on the other, lead to a putatively absurd conclusion, namely, a priori knowledge of the external world. I focus on arguments involving a variety of externalism resulting from the singularity or object-dependence of certain terms such as the demonstrative ‘that’. McKinsey (...) argues that incompatibilist arguments employing such externalist theses are at their strongest, and conclusively show that privileged access must be rejected. While I agree on the truth of the relevant externalist theses, I show that all plausible versions of the incompatibilist reductio argument as applied to such theses are fundamentally flawed, for these versions of the argument must make assumptions that lead to putatively absurd knowledge of the external world independently of the thesis of privileged access. (shrink)

Some recent discussions of a priori knowledge, taking their departure from Kant's characterization of such knowledge as being absolutely independent of experience, have concluded that while one might delineate a concept of a priori knowledge, it fails to have any application as any purported case of such knowledge can be undermined by suitably recalcitrant experiences. In response, certain defenders of apriority have claimed that a priori justification only requires that a belief be positively (...) dependent on no experience. In this paper, I begin by showing how the exchange of arguments between the disputants comes down, in the end, to no more than a display of conflicting intuitions. I shall then provide a diagnosis explaining how our explication of a priori justification depends on our standards for applying the term 'a priori' with this, in turn, reflecting our prior intentions as to whether we are willing to allow the existence of such warrants. I shall further argue that the claim that such knowledge can be affected by subversive experience is not entirely compatible with the spirit of apriority. Finally I conclude by making some methodological remarks about the prospects of a positive characterization of a priori knowledge by comparing it to the concept of knowledge. (shrink)

The main thesis defended in this paper is that Hildebrand’s distinction between what we could call quiddities—or “quasi-essences,” endowed with chaotic and accidental unity—and genuine essences possessing an intrinsically necessary unity, grounds the radical distinction between analytic and synthetic a priori knowledge. This thesis has not been expressly emphasized by Hildebrand himself. In order to prove it, we: relate the three types of unities distinguished by Hildebrand with the three kinds of judgments discriminated by Kant; outline what we (...) can call the “crux of empiricism”; analyze four characteristic examples of synthetic a priori judgements; and elaborate a provisional typology of synthetic a priori propositions, trying to include in it Hildebrand’s favorite examples. (shrink)

In his "The Empiricism of Avicenna," Dimitri Gutas interprets Avicenna as an empiricist.1 He analyzes Avicennian 'principles of syllogism' and claims that none of them are a priori. Moreover, regarding awwalīyāt and fiṭrīyāt—which are two groups of such principles—Gutas suggests that "[i]t appears that both kinds of propositions would be analytic, in Kantian terms. As for Locke, they would be what he called 'trifling.'"2 In my first comment in this issue, I disagreed with this view and argued that these (...) two groups of propositions are a priori in the Kantian sense. Assenting to their truth is internal to the intellect and independent of empirical information. I also argued that at least some fiṭrīyāt are synthetic... (shrink)

A review of J.R. Brown's second edition of The Laboratory of the Mind: Thought Experiments in the Natural Sciences.

The Theory of Relativity and A Priori Knowledge will hereafter be cited as "RAK. " The German edition is out of print. 2 H. Reichenbach, The Philosophy of ...