Theories of the A Priori

The terms "a priori" and "a posteriori" refer primarily to how or on what basis a proposition might be known. A proposition is knowable a priori if it is knowable independently of experience. A proposition is knowable a posteriori if it is knowable on the basis of experience. The a priori/a posteriori distinction is epistemological and should not be confused with the metaphysical distinction between the necessary and the contingent or the semantical or logical distinction between the analytic and the (...) synthetic. Two aspects of the a priori/a posteriori distinction require clarification: the conception of experience on which the distinction turns; and the sense in which a priori knowledge is independent of such experience. The latter gives rise to important questions regarding the positive basis of a priori knowledge. (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).

The topic of a priori knowledge is approached through the theory of evidence. A shortcoming in traditional formulations of moderate rationalism and moderate empiricism is that they fail to explain why rational intuition and phenomenal experience count as basic sources of evidence. This explanatory gap is filled by modal reliabilism -- the theory that there is a qualified modal tie between basic sources of evidence and the truth. This tie to the truth is then explained by the theory of concept (...) possession: this tie is a consequence of what, by definition, it is to possess (i.e., to understand) one’s concepts. A corollary of the overall account is that the a priori disciplines (logic, mathematics, philosophy) can be largely autonomous from the empirical sciences. (shrink)

The topic of a priori knowledge is approached through the theory of evidence. A shortcoming in traditional formulations of moderate rationalism and moderate empiricism is that they fail to explain why rational intuition and phenomenal experience count as basic sources of evidence. This explanatory gap is filled by modal reliabilism -- the theory that there is a qualified modal tie between basic sources of evidence and the truth. This tie to the truth is then explained by the theory of concept (...) possession: this tie is a consequence of what, by definition, it is to possess (i.e., to understand) one’s concepts. A corollary of the overall account is that the a priori disciplines (logic, mathematics, philosophy) can be largely autonomous from the empirical sciences. (shrink)

In the history of epistemology, discussions of the a priori have been bound up with discussions of necessity and analyticity, often in confusing ways. Disentangling these confusions is an essential step in the study of the a priori. This will be the aim of my introductory remarks. The goal of the remainder of the paper will then be to try to develop a unified account of the a priori, dealing with the notions of intuition and a priori evidence, the question (...) of why intuitions qualify as evidence, and the question of how they can be a reliable guide to the truth about a priori matters. (shrink)

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)

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)

Scientific essentialism is the view that some necessities 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 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)

In this paper I will argue that (principled) attempts to ground a priori knowledge in default reasonable beliefs cannot capture certain common intuitions about what is required for a priori knowledge. I will describe hypothetical creatures who derive complex mathematical truths like Fermat’s last theorem via short and intuitively unconvincing arguments. Many philosophers with foundationalist inclinations will feel that these creatures must lack knowledge because they are unable to justify their mathematical assumptions in terms of the kind of basic facts (...) which can be known without further argument. Yet, I will argue that nothing in the current literature lets us draw a principled distinction between what these creatures are doing and paradigmatic cases of good a priori reasoning (assuming that the latter are to be grounded in default reasonable beliefs). I will consider, in turn, appeals to reliability, coherence, conceptual truth and indispensability and argue that none of these can do the job. (shrink)

Here we challenge the orthodoxy according to which abduction is an a posteriori mode of inference. We start by providing a case study illustrating how abduction can justify a philosophical claim not justifiable by empirical evidence alone. While many grant abduction's epistemic value, nearly all assume that abductive justification is a posteriori, on grounds that our belief in abduction's epistemic value depends on empirical evidence about how the world contingently is. Contra this assumption, we argue, first, that our belief in (...) abduction’s epistemic value is not and could not be justified a posteriori, and second, that attention to the roles experience plays in abductive justification supports taking abduction to be an a priori mode of inference. We close by highlighting how our strategy for establishing the a priority of abduction positively contrasts with strategies in Bonjour (1998), Swinburne (2001), and Peacocke (2004) aiming to establish the a priority of certain ampliative modes of inference or abductive principles. (shrink)

This volume presents a series of influential essays by Paul Boghossian on the theory of content and on its relation to the phenomenon of a priori knowledge. The essays are organized under four headings: the nature of content; content and self-knowledge; knowledge, content, and the a priori; and colour concepts.

The paper is a defense of the project of explaining the a priori via the notion of meaning or concept possession. It responds to certain objections that have been made to this project—in particular, that there can be no epistemically analytic sentences that are not also metaphysically analytic, and that the notion of implicit definition cannot explain a priori entitlement. The paper goes on to distinguish between two different ways in which facts about meaning might generate facts about entitlement—inferential and (...) constitutive. It concludes by outlining a theory of the latter. (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 ...

In my book In Defense of Pure Reason, I offer an extended defense of the idea of a priori justification and, more specifically, of a rationalist conception of such justification: one according to which rational insight or intuition provides genuine justification for claims that need not be merely definitional or tautological in character. In the relatively brief space available to me on the present occasion, I want to present and defend, necessarily in rather broad strokes, four of the most central (...) claims that are discussed at much greater length in that book. I will say the most about the first of these theses, somewhat less about the second and third, and only a very little about the fourth. (shrink)

Carrie Jenkins (2005, 2008) has developed a theory of the a priori that she claims solves the problem of how justification regarding our concepts can give us justification regarding the world. She claims that concepts themselves can be justified, and that beliefs formed by examining such concepts can be justified a priori. I object that we can have a priori justified beliefs with unjustified concepts if those beliefs have no existential import. I then argue that only beliefs without existential import (...) can be justified a priori on the widely held conceptual approach. This limits the scope of the a priori and undermines arguments for essentialism. (shrink)

It seems to me that discussions of the past decades have made clear how intricate and complex the classical notion of the a priori is, and neither the Strong conception nor the Weak conception (nor anything else) can provide a coherent explication. (Kitcher 2000.

During the past decade a new twist in the debate regarding the a priori has unfolded. A number of prominent epistemologists have challenged the coherence or importance of the a priori—a posteriori distinction or, alternatively, of the concept of a priori knowledge. My focus in this paper is on these new challenges to the a priori. My goals are to provide a framework for organizing the challenges, articulate and assess a range of the challenges, and present two challenges of my (...) own. (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.

During the past decade a new twist in the debate regarding the a priori has unfolded. A number of prominent epistemologists have challenged the coherence or importance of the a priori—a posteriori distinction or, alternatively, of the concept of a priori knowledge. My focus in this paper is on these new challenges to the a priori. My goals are to (1) provide a framework for organizing the challenges, (2) articulate and assess a range of the challenges, and (3) present two (...) challenges of my own. (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.

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)

Philosophical Perspectives 19 (2005): 41-58.

The major divide in contemporary epistemology is between those who embrace and those who reject a priori knowledge. Albert Casullo provides a systematic treatment of the primary epistemological issues associated with the controversy. By freeing the a priori from traditional assumptions about the nature of knowledge and justification, he offers a novel approach to resolving these issues which assigns a prominent role to empirical evidence. He concludes by arguing that traditional approaches to the a priori, which focus primarily on the (...) concepts of necessity and analyticity, are misguided. (shrink)

Contents 1. Introduction 2. General Overviews 3. Textbooks 4. Anthologies 5. Historical Background to the Contemporary Debate 6. General Accounts 7. Mathematical Knowledge 8. Logical Knowledge 9. Intuitions and Conceptual Analysis 10. Modal Knowledge a. Overviews b. Primary Sources 11. Testimonial Knowledge 12. Naturalism 13. Scepticism 14. New Developments..

This thesis studies whether there is a tenable distinction between a priori justification and a posteriori justification. My research considers three possible conceptions of a priori: Justification Independent of Experience, Mere Meaning Based Justification and Justification by Rational Insight, and examines whether they can provide a sound and significant distinction between a priori and a posteriori. This thesis contains five chapters. Chapter 1 introduces the background knowledge of the a priori/a posteriori distinction. Chapter 2 analyzes the traditional conception of a (...) priori, i.e. justification independent of experience, and considers whether the distinction based on it is tenable. Five approaches for defining “experience” are examined, but none of them succeed in providing a distinction between a priori and a posteriori. Chapter 3 focuses on the empiricist conception of the a priori, i.e. a priori as mere meaning based justification, and argues that the distinction based on it has a problem of classification. Chapter 4 concerns the rationalist conception of the a priori, i.e. a priori as justification by rational insight, and argues that neither the idea of justification by rational insight itself nor the distinctive features of rational insight could provide a distinction between a priori and a posteriori. Given that none of the current major accounts seem to work, we should not be optimistic about the potential for success in accounting for the distinction between a priori and a posteriori. In the last chapter, I will conclude the thesis and point out the implication of abandoning the a priori/a posteriori distinction: a need to reform our understanding of the nature of different sources of justification and knowledge. (shrink)