Online research in philosophy

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.

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.

Book Information New Essays on the A Priori. Edited by Paul Boghossian and Christopher Peacocke. Oxford University Press. Oxford. 2000. Pp. xi + 478. £15.99.

This article provides the first comprehensive reconstruction and analysis of Hintikka’s attempt to obtain a measure of the information yield of deductive inferences. The reconstruction is detailed by necessity due to the originality of Hintikka’s contribution. The analysis will turn out to be destructive. It dismisses Hintikka’s distinction between surface information and depth information as being of any utility towards obtaining a measure of the information yield of deductive inferences. Hintikka is right to identify the failure of canonical information theory to give an account of the information yield of deductions as a scandal, however this article demonstrates that his attempt to provide such an account fails. It fails primarily because it applies to only a restricted set of deductions in the polyadic predicate calculus, and fails to apply at all to the deductions in the monadic predicate calculus and the propositional calculus. Some corollaries of these facts are a number of undesirable and counterintuitive results concerning the proposed relation of linguistic meaning (and hence synonymy) with surface information. Some of these results will be seen to contradict Hintikka’s stated aims, whilst others are seen to be false. The consequence is that the problem of obtaining a measure of the information yield of deductive inferences remains an open one. The failure of Hintikka’s proposal will suggest that a purely syntactic approach to the problem be abandoned in favour of an intrinsically semantic one.

Kant wrote two versions of the Transcendental Deduction, the first, “A-”Deduction in 1781, and the second, “B-”Deduction in 1787. Since Henrich's “The Proof Structure of Kant's Transcendental Deduction”, most work on the Transcendental Deduction attempts to make sense of the B-Deduction's two-step argument structure. Though the A-Deduction has suffered comparative neglect, it has received some attention from interpreters who take its extended treatment of the “subjective” side of cognition to amount to a brand of proto-functionalism. Whatever the merits and demerits of these proto-functionalist approaches, they tend to deemphasize the two arguments that constitute the “objective” side of the A-Deduction, the “argument from above” and then the “argument from below”. Since Kant himself refers to this objective side of the A-Deduction as the “Deduction of the Pure Concepts of the Understanding”, it is surprising that the structure of these arguments has not received closer scrutiny. This is doubly true since Kant actually claims that his revisions for the 1787 version of the Deduction impacted only the “presentation” of it. Any lessons learned from the central arguments of the A-Deduction should help clarify the structure of its younger and more closely studied brother.

Several different kinds of measures of information are distinguished from each other. The differences between them show that our pretheoretical concept of information is multiply ambiguous. Attempts to think of the scientific enterprise in terms of information maximization lead to several legitimately different rules of scientific decision-making, depending on which kind of information one is interested in. The contrast between high information and high probability postulated by some philosophers is spurious for the same reason. It is even possible to define interesting measures of information such that nontrivial deductive reasoning can increase information so defined.

What has come to be known as “a priori physicalism” is the thesis, roughly, that the non-physical truths in the actual world can be deduced a priori from a complete physical description of the actual world. To many contemporary philosophers, a priori physicalism seems extremely implausible. In this paper I distinguish two kinds of a priori physicalism. One sort – strict a priori physicalism – I reject as both unmotivated and implausible. The other sort – liberal a priori physicalism – I argue is both motivated and plausible. This variety of a priori physicalism insists that the necessitation of non-physical truths by the physical facts must be underwritten in a certain fashion by a priori knowledge, but the a priori knowledge need not amount to a simple deduction of the non-physical truths from a complete physical description of the world. Further, this sort of liberal a priori physicalism has the advantage that it offers hope for a genuinely satisfying account of how the physical facts manage to necessitate the facts about phenomenal consciousness – thereby in effect solving the “hard problem” of consciousness. The first half of the paper sets out the motivation for liberal a priori physicalism and its superiority to the strict version; the second half presents one strategy available to the liberal a priori physicalist for showing how consciousness can be accommodated in a purely physical world.

I argue that §§15–20 of the B-Deduction contain two independent arguments for the applicability of a priori concepts, the first an argument from above, the second an argument from below. The core of the first argument is §16's explanation of our consciousness of subject-identity across self-attributions, while the focus of the second is §18's account of universality and necessity in our experience. I conclude that the B-Deduction comprises powerful strategies for establishing its intended conclusion, and that some assistance from empirical psychology might well have produced a completely successful argument.