Online research in philosophy

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

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.

Hilary Putnam has famously argued that we can know that we are not brains in a vat because the hypothesis that we are is self-refuting.1 While Putnam’s argument has generated interest primarily as a novel response to skepticism, his original use of the brain in a vat scenario was meant to illustrate a point about the “mind/world relationship.”2 In particular, he intended it to be part of an argument against the coherence of metaphysical realism, and thus to be part of a defense of his conception of truth as idealized rational acceptability. Putnam’s argument has drawn a good deal of criticism already, but it will be argued here that these criticisms fail to capture the central problem with Putnam’s argument. Putnam’s conclusions about the self refuting character of the brain in a vat hypothesis, rather than simply being a consequence of his semantic externalism, will be shown to be actually out of line with central and plausible aspects of his own account of the relationship between our minds and the world. Reflections on intentionality and semantics ultimately give us no compelling reason to suppose that the beliefs expressed by claims like “I am a brain in a vat” could not be true,3 but (pace Putnam) this supports neither skepticism nor metaphysical realism.

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.

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.

In the 1960s and 1970s, Hilary Putnam articulated a notion of relativized apriority that was motivated to address the problem of scientific change. This paper examines Putnam’s account in its historical context and in relation to contemporary views. I begin by locating Putnam’s analysis in the historical context of Quine’s rejection of apriority, presenting Putnam as a sympathetic commentator on Quine. Subsequently, I explicate Putnam’s positive account of apriority, focusing on his analysis of the history of physics and geometry. In the remainder of the paper, I explore connections between Putnam’s account of relativized a priori principles and contemporary views. In particular, I situate Putnam’s account in relation to analyses advanced by Michael Friedman, David Stump, and William Wimsatt. From this comparison, I address issues concerning whether a priori scientific principles are appropriately characterized as “constitutive” or “entrenched”. I argue that these two features need to be clearly distinguished, and that only the constitutive function is essential to apriority. By way of conclusion, I explore the relationship between the constitutive function of a priori principles and entrenchment.

Nevertheless, when we cannot specify how a statement may actually be false it has a special methodological status for us, according to Putnam—it is contextually a priori . In these circumstances, he suggests, it is epistemically reasonable for us to accept the statement without evidence and hold it immune from disconfirmation.