Tomoji Shogenji

This paper aims to reconcile (i) the intuitively plausible view that a higher degree of coherence among independent pieces of evidence makes the hypothesis they support more probable, and (ii) the negative results in Bayesian epistemology to the effect that there is no probabilistic measure of coherence such that a higher degree of coherence among independent pieces of evidence makes the hypothesis they support more probable. I consider a simple model in which the negative result appears in a stark form: the prior probability of the hypothesis and the individual vertical relations between each piece of evidence and the hypothesis completely determine the conditional probability of the hypothesis given the total evidence, leaving no room for the lateral relation (such as coherence) among the pieces of evidence to play any role. Despite this negative result, the model also reveals that a higher degree of coherence is indirectly associated with a higher conditional probability of the hypothesis because a higher degree of coherence indicates stronger individual supports. This analysis explains why coherence appears truth-conducive but in such a way that it defeats the idea of coherentism since the lateral relation (such as coherence) plays no independent role in the confirmation of the hypothesis.

This paper describes a formal measure of epistemic justification motivated by the dual goal of cognition, which is to increase true beliefs and reduce false beliefs. From this perspective the degree of epistemic justification should not be the conditional probability of the proposition given the evidence, as it is commonly thought. It should be determined instead by the combination of the conditional probability and the prior probability. This is also true of the degree of incremental confirmation, and I argue that any measure of epistemic justification is also a measure of incremental confirmation. However, the degree of epistemic justification must meet an additional condition, and all known measures of incremental confirmation fail to meet it. I describe this additional condition as well as a measure that meets it. The paper then applies the measure to the conjunction fallacy and proposes an explanation of the fallacy.

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s “proof” of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive

This paper addresses the issue of rule-following in the context of the problem of the criterion. It presents a line of reasoning which concludes we do not know what rule we follow, but which develops independently of the problem of extrapolation that plays a major role in many recent discussions of rule-following. The basis of the argument is the normativity of rules, but the problem is also distinct from the issue of the gap between facts and values in axiology. The paper further points out that the epistemic problem of not knowing what rule we follow leads to the outright denial of rule-following.

This paper disputes the widely held view that one cannot establish the reliability of a belief-forming process with the use of belief's that are obtained by that very process since such self-dependent justification is circular. Harold Brown ([1993]) argued in this journal that some cases of self-dependent justification are legitimate despite their circularity. I argue instead that under appropriate construal many cases of self-dependent justification are not truly circular but are instances of ordinary Bayesian confirmation, and hence they can raise the probability of the hypothesis as legitimately as any such confirmation does. I shall argue in particular that despite its dependence on perception we can use naturalized epistemology to confirm the reliability of a perceptual process without circularity.

It is well known that probabilistic support is not transitive. But it can be shown that probabilistic support is transitive provided the intermediary proposition screens off the original evidence with respect to the hypothesis in question. This has the consequence that probabilistic support is transitive when the original evidence is testimonial, memorial or perceptual (i.e., to the effect that such and such was testified to, remembered, or perceived), and the intermediary proposition is its representational content (i.e., to the effect that the such and such occurred).

This paper examines the epistemic status of the reflective belief about the content of one’s own conscious mental state, with emphasis on perceptual experience. I propose that the process that gives a special epistemic status to a reflective belief is not observation, inference, or conceptual articulation, but semantic ascent similar to the transition from a sentence in the object language to a sentence in the meta-language that affirms the truth of the original sentence. This account of the process of reflection explains why a reflective belief is (subject to some qualification) infallible.

The proportional weight view in epistemology of disagreement generalizes the equal weight view and proposes that we assign to judgments of different people weights that are proportional to their epistemic qualifications. It is shown that if the resulting degrees of confidence are to constitute a probability function, they must be the weighted arithmetic means of individual degrees of confidence, while if the resulting degrees of confidence are to obey the Bayesian rule of conditionalization, they must be the weighted geometric means of individual degrees of confidence. The double bind entails that the proportional weight view (and its moderate adjustment in favor of one’s own judgment) is inconsistent with Bayesianism.

This paper examines how coherence of the contents of evidence affects the transmission of probabilistic support from the evidence to the hypothesis. It is argued that coherence of the contents in the sense of the ratio of the positive intersection reduces the transmission of probabilistic support, though this negative impact of coherence may be offset by other aspects of the relations among the contents. It is argued further that there is no broader conception of coherence whose impact on the transmission of probabilistic support is never offset by other aspects of the relations among the contents. The paper also examines reasons for the contrary impression that coherence of the contents increases the transmission of probabilistic support, especially in the special case where the hypothesis to evaluate is the conjunction of the contents of evidence.

We show that as a chain of confirmation becomes longer, confirmation dwindles under screening-off. For example, if E confirms H1, H1 confirms H2, and H1 screens off E from H2, then the degree to which E confirms H2 is less than the degree to which E confirms H1. Although there are many measures of confirmation, our result holds on any measure that satisfies the Weak Law of Likelihood. We apply our result to testimony cases, relate it to the Data-Processing Inequality in information theory, and extend it in two respects so that it covers a broader range of cases.

Among many reasons for which contemporary philosophers take coherentism in epistemology seriously, the most important is probably the perceived inadequacy of alternative accounts, most notably misgivings about foundationalism. But coherentism also receives straightforward support from cases in which beliefs are apparently justified by their coherence. From the perspective of those against coherentism, this means that an explanation is needed as to why in these cases coherence apparently justifies beliefs. Curiously, this task has not been carried out in a serious way in the anti-coherentist literature although there is no scarcity of objections to coherentism. The traditional charge has been that justification by coherence is circular. More recently the isolation problem allegedly reveals that coherentism justifies beliefs that should not be justified. Questions have also been raised with respect to the basing relation and feasibility.1 However, these objections do not explain why some beliefs appear to be justified by their coherence. This paper fills this gap in the anti-coherentist literature by offering a noncoherentist account of justification by coherence. The paper proceeds as follows. Section I delineates the framework of discussion and develops some conceptual tools needed in later analyses. Section II argues that there are genuine cases of an increase in existing empirical justification by coherence, but that it does not require coherence to generate additional justification—coherence serves as a channel of justification among beliefs, which is no more problematic than channeling of justification from basic to derived beliefs in foundationalism. Section III makes a stronger case for justification by coherence, where each of the coherent beliefs has no independent empirical justification; but Section IV argues that even in these cases coherence need not generate justification—coherence licenses the channeling of justification from outside sources..