What does it mean for a hypothesis to be ad hoc? One prominent account has it that ad hoc hypotheses have no independent empirical support. Others have viewed ad hoc judgements as subjective. Here I critically review both of these views and defend my own Coherentist Conception of Ad hocness by working out its conceptual and descriptive attractions.

Synchronic intertheoretic reductions are an important field of research in science. Arguably, the best model able to represent the main relations occurring in this kind of scientific reduction is the Nagelian account of reduction, a model further developed by Schaffner and nowadays known as the generalized version of the Nagel–Schaffner model. In their article, Dizadji-Bahmani, Frigg, and Hartmann specified the two main desiderata of a reduction á la GNS: confirmation and coherence. DFH first and, more rigorously, Tešic later analyse the (...) confirmatory relation between the reducing and the reduced theory in terms of Bayesian confirmation theory. The purpose of this article is to analyse and compare the degree of coherence between the two theories involved in the GNS before and after the reduction. For this reason, in the first section, I will be looking at the reduction of thermodynamics to statistical mechanics and use it as an example to describe the GNS. In the second section, I will introduce three coherence measures which will then be employed in the comparison. Finally, in the last two sections, I will compare the degrees of coherence between the reducing and the reduced theory before and after the reduction and use a few numerical examples to understand the relation between coherence and confirmation measures. (shrink)

The coherence of independent reports provides a strong reason to believe that the reports are true. This plausible claim has come under attack from recent work in Bayesian epistemology. This work shows that, under certain probabilistic conditions, coherence cannot increase the probability of the target claim. These theorems are taken to demonstrate that epistemic coherentism is untenable. To date no one has investigated how these results bear on different conceptions of coherence. I investigate this situation using Thagard’s ECHO model of (...) explanatory coherence. Thagard’s ECHO model provides a natural representation of the evidential significance of multiple independent reports. (shrink)

It is a widespread intuition that the coherence of independent reports provides a powerful reason to believe that the reports are true. Formal results by Huemer, M. 1997. “Probability and Coherence Justification.” Southern Journal of Philosophy 35: 463–72, Olsson, E. 2002. “What is the Problem of Coherence and Truth?” Journal of Philosophy XCIX : 246–72, Olsson, E. 2005. Against Coherence: Truth, Probability, and Justification. Oxford University Press., Bovens, L., and S. Hartmann. 2003. Bayesian Epistemology. Oxford University Press, prove that, under (...) certain conditions, coherence cannot increase the probability of the target claim. These formal results, known as ‘the impossibility theorems’ have been widely discussed in the literature. They are taken to have significant epistemic upshot. In particular, they are taken to show that reports must first individually confirm the target claim before the coherence of multiple reports offers any positive confirmation. In this paper, I dispute this epistemic interpretation. The impossibility theorems are consistent with the idea that the coherence of independent reports provides a powerful reason to believe that the reports are true even if the reports do not individually confirm prior to coherence. Once we see that the formal discoveries do not have this implication, we can recover a model of coherence justification consistent with Bayesianism and these results. This paper, thus, seeks to turn the tide of the negative findings for coherence reasoning by defending coherence as a unique source of confirmation. (shrink)

Hearsay or indirect testimony receives little discussion even today in epistemology, and yet it represents one of the cardinal modes for the transmission of knowledge and for human cognitive development. It suffices to think of school education whereby a student listens to teachers reporting knowledge acquired, often indirectly, from the most varied sources such as text books, newspapers, personal memory, television, etc… Or let us consider the importance of oral tradition in the social and cultural development of civilisations. Or even (...) let us call to mind the learning process of infants who, only thanks to the knowledge learned from others, succeed in learning the language. Finally, with the emerging digital technology, the information gleaned from third parties is influencing the creation of knowledge in a full gamut of fields, in a quasi-comprehensive manner. This leads us to claim that hearsay, despite the reductionist conceptual scheme to which epistemology has confined it in that indirect testimony, is in any case quintessential in the dissemination of knowledge. This work fully expounds upon the basic mechanism of indirect testimonial transmission and provides an epistemologically founded explanation of the cognitive possibilities of hearsay by investigating, in the light of the anti-reductionist paradigm, three mutually connected epistemic properties, namely trust, reputation and coherence, that are key in the epistemic justification of the truth acquired via an indirect testimony. (shrink)

Evolutionary debunkers claim that evolutionary explanations of moral phenomena lead to sceptical conclusions. The aim of this paper is to show that even if we grant debunkers the speculative claims that evolution provides the best explanation of moral phenomena and that there are no other moral phenomena for which moral facts/properties are indispensable, the sceptical conclusions debunkers seek to establish still do not follow. The problem for debunkers is to link the empirical explanatory claim to the normative conclusion that moral (...) beliefs are unjustified. The paper argues that debunkers face a dilemma, and that neither of the two options available to them supports the sceptical conclusions for which they aim. Consequently, it is claimed, the dialectical force of evolutionary debunking arguments is, at best, exceedingly weak. (shrink)

How can we determine the adequacy of a probabilistic coherence measure? A widely accepted approach to this question besides formulating adequacy constraints is to employ paradigmatic test cases consisting of a scenario providing a joint probability distribution over some specified set of propositions coupled with a normative coherence assessment for this set. However, despite the popularity of the test case approach, a systematic evaluation of the proposed test cases is still missing. This paper’s aim is to change this. Using a (...) custom written computer program for the necessary probabilistic calculations a large number of coherence measures in an extensive collection of test cases is examined. The result is a detailed overview of the test case performance of any probabilistic coherence measures proposed so far. It turns out that none of the popular coherence measures such as Shogenji’s, Glass’ and Olsson’s, Fitelson’s or Douven and Meijs’ but two rather unnoticed measures perform best. This, however, does not mean that the other measures can be rejected straightforwardly. Instead, the results presented here are to be understood as a contribution among others to the project of finding adequate probabilistic coherence measures. (shrink)

Knowledge about human wellbeing is a central part of ethical knowledge. But it is a neglected topic not only in ethics in general, but also in wellbeing theorizing, which has focused on enumerating the basic elements of wellbeing rather than on how to gauge, foster and maintain wellbeing in actual human lives. I consider the prospects for a procedural approach to wellbeing that sees it as depending on a process of continual adjustment between values, preferences, actions and emotions. The value-fulfilment (...) theory of Valerie Tiberius provides a model for such an approach, but needs to be corrected and supplemented in certain respects. I propose a version of the approach that is only partly, but still significantly procedural, and which does not privilege higher-order mental states. Considering the relevance of such an approach for ethics, I finally suggest that (certain forms of) moral agency may be best analyzed as an intersubjective process of adjustment and fulfilment of values and desires (etc.), and as a process of acquiring and exercising collective moral knowing how. (shrink)

Speaking with conversational AIs, technologies whose interfaces enable human-like interaction based on natural language, has become a common phenomenon. During these interactions, people form their beliefs due to the say-so of conversational AIs. In this paper, I consider, and then reject, the concepts of testimony-based beliefs and instrument-based beliefs as suitable for analysis of beliefs acquired from these technologies. I argue that the concept of instrument-based beliefs acknowledges the non-human agency of the source of the belief. However, the analysis focuses (...) on perceiving signs and indicators rather than content expressed in natural language. At the same time, the concept of testimony-based beliefs does refer to natural language propositions, but there is an underlying assumption that the agency of the testifier is human. To fill the lacuna of analyzing belief acquisition from conversational AIs, I suggest a third concept: technology-based beliefs. It acknowledges the non-human agency-status of the originator of the belief. Concurrently, the focus of analysis is on the propositional content that forms the belief. Filling the lacuna enables analysis that considers epistemic, ethical, and social issues of conversational AIs without excluding propositional content or compromising accepted assumptions about the agency of technologies. (shrink)

Reliabilism is an intuitive and attractive view about epistemic justification. However, it has many well-known problems. I offer a novel condition on reliabilist theories of justification. This method coherence condition requires that a method be appropriately tested by appeal to a subject’s other belief-forming methods. Adding this condition to reliabilism provides a solution to epistemic circularity worries, including the bootstrapping problem.

A novel solution is offered for how emotional experiences can function as sources of immediate prima facie justification for evaluative beliefs, and in such a way that suffices to halt a justificatory regress. Key to this solution is the recognition of two distinct kinds of emotional skill (what I call generative emotional skill and doxastic emotional skill) and how these must be working in tandem when emotional experience plays such a justificatory role. The paper has two main parts, the first (...) negative and the second positive. The negative part criticises the epistemic credentials of Epistemic Perceptualism (e.g., Tappolet 2012, 2016; Doring 2003, 2007; Elgin 2008; Roberts 2003), the view that emotional experience alone suffices to prima facie justify evaluative beliefs in a way that is analogous to how perceptual experience justifies our beliefs about the external world. The second part of the paper develops an account of emotional skill and uses this account to frame a revisionary form of Epistemic Perceptualism that succeeds where the traditional views could not. I conclude by considering some objections and replies. (shrink)

Paul Thagard’s theory of deductive coherence, as set out in his Coherence in Thought and Action, faces a regress objection. Thagard’s method of solving deductive coherence problems presupposes some notion of logical consequence. The problem of specifying which logic to use to this end is itself a deductive coherence problem, so we would expect Thagard’s theory to be able to solve it. However, on pain of regress, the theory of deductive coherence cannot reach such a solution.

This paper aims at comparing and relating belief revision and argumentation as approaches to model reasoning processes. Referring to some prominent literature references in both fields, we will discuss their (implicit or explicit) assumptions on the modeled processes and hence commonalities and differences in the forms of reasoning they are suitable to deal with. The intended contribution is on one hand assessing the (not fully explored yet) relationships between two lively research fields in the broad area of defeasible reasoning and (...) on the other hand pointing out open issues and potential directions for future research. (shrink)

Even if two testimonies in a criminal trial are independent, they are not necessarily more trustworthy than one. But if they are independent in the sense that they are screened off from one another by the crime, then two testimonies raise the probability of guilt above the level that one testimony alone could achieve. In fact this screening-off condition can be weakened without changing the conclusion. It is however only a sufficient, not a necessary condition for concluding that two witnesses (...) are better than one. We will discuss two different conditions, each of them necessary as well as sufficient, and we conclude that one of them is slightly better than the other. (shrink)

Coherence between propositions promises to fix the vexing circumstance of prior probabilities for subjective Bayesians. This paper examines the role of coherence as a source of justification for Bayesian agents, particularly the argument that all propositions must cohere within an agent’s ‘web of belief’, aka confirmational holism. Unfortunately, Confirmational holism runs across a potentially devastating argument that a more coherent set of beliefs resulting from the addition of a belief to a less coherent set of beliefs is less likely to (...) be true than the less coherent set of beliefs. In response, I propose confirmational chorism to avoid this troubling outcome. CC posits that coherence adds epistemic justification by limited, logically consistent sets of beliefs exhibiting a satisficing degree of strength, inferential and explanatory connection. Limited coherence may resolve the above argument, but raises the need for another kind of justification: coordination. Belief coordination requires suppressing some beliefs and communicating other beliefs to ensure convergence on the right action for performance success. Thus, a Bayesian formed belief in any particular context is justified not just because it is reliably formed and coherent, but also because of how it is coordinated between local and holistic goals. (shrink)

This paper examines the role of coherence as a source of epistemic justification, particularly the argument that all beliefs must cohere within one’s ‘web of belief’, aka confirmational holism. Confirmational holism runs across a potentially devastating argument that a more coherent set of beliefs resulting from the addition of a belief to a less coherent set of beliefs is less likely to be true than the less coherent set of beliefs. I propose confirmational chorism to avoid this troubling outcome. CC (...) posits that coherence adds epistemic justification by limited, logically consistent sets of beliefs exhibiting a satisficing degree of strength, inferential and explanatory connection. Limited coherence may resolve the above argument, but raises the need for another kind of justification: coordination. Belief coordination requires suppressing some beliefs and communicating other beliefs to ensure convergence on the right action for performance success. Thus, a belief in any particular context is justified not just because it is reliably formed and coherent, but also because of how it is coordinated between local and holistic goals. (shrink)