Albert Casullo

In “A Priori Knowledge,” Albert Casullo asks whether there is a priori knowledge. He ultimately defines a priori knowledge as true belief with a priori justification, where a belief is a priori justified if it is nonexperientially justified. Armed with this definition, Casullo evaluates several traditional arguments for and against the existence of a priori knowledge. He concludes that the traditional arguments reach an impasse by arguing on a priori grounds that the opposite position is deficient. A successful way to defend a priori knowledge, he argues, would be to find empirical evidence that supports the existence of nonexperiential sources of justification.

E. J. Lowe offers an account of modal knowledge that involves two primary theses. First, the basis of modal knowledge is essential knowledge, and the source of essential knowledge is grasp of essence. Second, all empirical knowledge ultimately depends on some modal knowledge. This article assesses Lowe’s account and defends four conclusions. First, there is a tension in Lowe’s account of grasp of essence; it wavers between an undemanding version, which holds that grasp of essence requires no more than our ordinary understanding of propositions, and a more demanding version, which holds that it requires rational insight into necessary relationships between essences. Second, both versions face serious challenges. Third, Lowe’s account of knowledge of essence does not provide a basis for modal knowledge. Fourth, Lowe’s supporting argument for his second thesis contains two significant gaps and the principles necessary to close the gaps reveal further tensions in his epistemological views.

Kant contends that necessity is a criterion of the a priori—that is, that all knowledge of necessary propositions is a priori. This contention, together with two others that Kant took to be evident—we know some mathematical propositions and such propositions are necessary—leads directly to the conclusion that some knowledge is a priori. Although many contemporary philosophers endorse Kant’s criterion, supporting arguments are hard to come by. Gordon Barnes provides one of the few examples. My purpose in this chapter is to articulate and examine his argument. I have two goals in doing so. The first is to uncover several significant gaps in the argument. The second is to show that it suffers from a common defect in rationalist arguments. If the argument were successful against empiricist accounts of modal knowledge, it would apply with equal force to extant rationalist accounts of such knowledge. Hence, the cost of refuting modal empiricism is modal scepticism.

In Necessary Beings, Bob Hale addresses two questions: What is the source of necessity? What is the source of our knowledge of it? He offers novel responses to them in terms of the metaphysical notion of nature or, more familiarly, essence. In this paper, I address Hale’s response to the first question. My assessment is negative. I argue that his essentialist explanation of the source of necessity suffers from three significant shortcomings. First, Hale’s leading example of an essentialist explanation merely asserts that the nature of an entity explains some necessity, but leaves unexplained how it does so. Second, his essentialist explanation of particular necessities introduces new necessities that remain unexplained. Third, Hale’s version of essentialism presupposes a controversial metaphysical theory of properties, for which he offers no defense.

Christopher Hill contends that the metaphysical modalities can be reductively explained in terms of the subjunctive conditional and that this reductive explanation yields two tests for determining the metaphysical modality of a proposition. He goes on to argue that his reductive account of the metaphysical modalities in conjunction with his account of modal knowledge underwrites the further conclusion that conceivability does not provide a reliable test for metaphysical possibility. I argue (1) that Hill’s reductive explanation of the metaphysical modalities in terms of the subjunctive conditional does not yield a reductive explanation of knowledge of metaphysical modality in terms of knowledge of subjunctive conditionals, and (2) that his account of modal knowledge is at odds with his contention that conceivability does not provide epistemic access to metaphysical possibility.

Tyler Burge offers a theory of testimony that allows for the possibility of both testimonial a priori warrant and testimonial a priori knowledge. I uncover a tension in his account of the relationship between the two, and locate its source in the analogy that Burge draws between testimonial warrant and preservative memory. I contend that this analogy should be rejected, and offer a revision of Burge's theory that eliminates the tension. I conclude by assessing the impact of the revised theory on the scope of a priori knowledge

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.

My purpose in this paper is to examine the role of intuition in conceptual analysis and to assess whether that role can be parlayed into a plausible defense of a priori knowledge. The focus of my investigation is George Bealer’s attempt to provide such a defense. I argue that Bealer’s account of intuition and its evidential status faces three problems. I go on to examine the two primary arguments that Bealer offers against empiricism: the Starting Points Argument and the Argument from Epistemic Norms. I argue that the Starting Points Argument fails because Bealer fails to show that intuitions are a priori evidence and that the Argument from Epistemic Norms fails because it is open to the Stalemate Problem. I conclude by offering an alternative approach to defending the a priori status of intuitions that avoids the Stalemate Problem. The alternative approach highlights the role of empirical investigation in defending the a priori.

The distinction between a priori knowledge and a posteriori knowledge has come under attack in the recent literature by Philip Kitcher, John Hawthorne, C. S. Jenkins, and Timothy Williamson. Evaluating the attacks requires answering two questions. First, have they hit their target? Second, are they compelling? My goal is to argue that the attacks fail because they miss their target. Since the attacks are directed at a particular concept or distinction, they must accurately locate the target concept or distinction. Accurately locating the target concept or distinction requires correctly articulating that concept or distinction. The attacks miss their target because they fail to correctly articulate the target concept or distinction. I go on to present a different challenge to the a priori-a posteriori distinction. This challenge is not directed at the coherence or significance of the distinction. Its target is the traditional view that all knowledge (or justified belief) is either a priori or a posteriori.

In his seminal paper, Content Preservation, Tyler Burge defends an original account of testimonial knowledge. The originality of the account is due, in part, to the fact that it is cast within a novel epistemic framework. The central feature of that framework is the introduction of the concept of entitlement, which is alleged to be a distinctive type of positive epistemic support or warrant. Entitlement and justification, according to Burge, are sub-species of warrant. Justification is the internalist form of warrant, but entitlement is epistemically externalist. My focus in this paper is Burge’s conception of entitlement, and there are three primary issues that I wish to address. What is the relationship between entitlement and the more traditional concept of justification? In what sense is entitlement epistemically externalist? Has Burge introduced a new epistemic concept or merely coined a new term for a familiar epistemic concept?

For much of the past two millennia philosophers have embraced a priori knowledge and have thought that the a priori plays an important role in philosophy itself. Philosophers from Plato to Descartes, Kant to Kripke, all endorse the a priori and engage in a priori reasoning in their philosophical discussions. Recent work in epistemology and experimental philosophy, however, has raised questions about both the existence of a priori knowledge and the centrality of the a priori for philosophy. This collection of essays aims to advance the discussion of the a priori and its role in philosophy. The contributors include a mix of young and established philosophers, including some of the most prominent voices in philosophy today.