Many epistemological problems can be solved by the objective Bayesian view that there are rationality constraints on priors, that is, inductive probabilities. But attempts to work out these constraints have run into such serious problems that many have rejected objective Bayesianism altogether. I argue that the epistemologist should borrow the metaphysician’s concept of naturalness and assign higher priors to more natural hypotheses.

The epistemic probability of A given B is the degree to which B evidentially supports A, or makes A plausible. This paper is a first step in answering the question of what determines the values of epistemic probabilities. I break this question into two parts: the structural question and the substantive question. Just as an object’s weight is determined by its mass and gravitational acceleration, some probabilities are determined by other, more basic ones. The structural question asks what probabilities are (...) not determined in this way—these are the basic probabilities which determine values for all other probabilities. The substantive question asks how the values of these basic probabilities are determined. I defend an answer to the structural question on which basic probabilities are the probabilities of atomic propositions conditional on potential direct explanations. I defend this against the view, implicit in orthodox mathematical treatments of probability, that basic probabilities are the unconditional probabilities of complete worlds. I then apply my answer to the structural question to clear up common confusions in expositions of Bayesianism and shed light on the “problem of the priors.”. (shrink)

What is the relationship between conceptual engineering and metasemantic externalism? Sally Haslanger has argued that metasemantic externalism justifies the seemingly counterintuitive consequences of her proposed conceptual revisions. But according to Herman Cappelen, metasemantic externalism makes conceptual engineering effectively impossible in practice. After raising objections to Haslanger’s and Cappelen’s views, I argue for a very different picture, on which metasemantic externalism bears very little on conceptual engineering. I argue that, while metasemantic externalism principally operates at the level of semantic-meaning, we should (...) understand conceptual engineering to operate largely at the level of speaker-meaning. This ‘Speaker-Meaning Picture’ has two key benefits. Firstly, it makes conceptual engineering often easy in practice. Secondly, it suggests a new, normative response to the well known objection that conceptual engineering serves only to change the subject. (shrink)

According to a widespread but implicit thesis in Bayesian confirmation theory, two confirmation measures are considered equivalent if they are ordinally equivalent—call this the “ordinal equivalence thesis” (OET). I argue that adopting OET has significant costs. First, adopting OET renders one incapable of determining whether a piece of evidence substantially favors one hypothesis over another. Second, OET must be rejected if merely ordinal conclusions are to be drawn from the expected value of a confirmation measure. Furthermore, several arguments and applications (...) of confirmation measures given in the literature already rely on a rejection of OET. I also contrast OET with stronger equivalence theses and show that they do not have the same costs as OET. On the other hand, adopting a thesis stronger than OET has costs of its own, since a rejection of OET ostensibly implies that people’s epistemic states have a very fine-grained quantitative structure. However, I suggest that the normative upshot of the paper in fact has a conditional form, and that other Bayesian norms can also fruitfully be construed as having a similar conditional form. (shrink)

A probability distribution is regular if it does not assign probability zero to any possible event. While some hold that probabilities should always be regular, three counter-arguments have been posed based on examples where, if regularity holds, then perfectly similar events must have different probabilities. Howson and Benci et al. have raised technical objections to these symmetry arguments, but we see here that their objections fail. Howson says that Williamson’s “isomorphic” events are not in fact isomorphic, but Howson is speaking (...) of set-theoretic representations of events in a probability model. While those sets are not isomorphic, Williamson’s physical events are, in the relevant sense. Benci et al. claim that all three arguments rest on a conflation of different models, but they do not. They are founded on the premise that similar events should have the same probability in the same model, or in one case, on the assumption that a single rotation-invariant distribution is possible. Having failed to refute the symmetry arguments on such technical grounds, one could deny their implicit premises, which is a heavy cost, or adopt varying degrees of instrumentalism or pluralism about regularity, but that would not serve the project of accurately modelling chances. (shrink)

This paper evaluates four different qualitative (probabilistic) accounts to coherence with a focus on structural properties (symmetries, asymmetries, and transitivity). It is shown that while coherence is not transitive on any of these accounts, there are screening-off conditions that render coherence transitive. In a second step, an array of quantitative (probabilistic) accounts to coherence is considered. The upshot is that extant measures differ considerably with respect to a number of symmetry constraints.

An important question in the current debate on the epistemic significance of peer disagreement is whether evidence of evidence is evidence. Fitelson argues that, at least on some renderings of the thesis that evidence of evidence is evidence, there are cases where evidence of evidence is not evidence. I introduce a condition and show that under this condition evidence of evidence is evidence.

Je vais traiter ici des inférences dont la validité tient au rôle qu'y jouent les cinq connecteurs « ⊃ », « ∼ », « & », « V » et « ≡ », les deux quantificateurs « ∀ » et « ∃ », et le signe d'identité « = ». Qu'on me permette de rappeler que les deux conjectures présentéd dans ma première étude se sont avéré'es justes. En premier lieu, toute règle de structure et toute règie d'élimination ou d'introduction (...) pour « & » ou « V » qui vaut pour la logique classique des connecteurs vaut également pour la logique intuitionniste des connecteurs. En second lieu, tout énoncé du genre A1, A2, …, An ⊢ B qui vaut pour la logique classique des connecteurs peut s'obtenir exclusivement à l'aide des règles de structure R, P, E, S, et des règles d'elimination et d'introduction pour ceux des connecteurs « ⊃ », « ∼ », « & », « V » et « ≡ » qui figurent dans A1, A2, …, An, et B. (shrink)

Most handbooks on statistics and the theory of probability leave the reader in a mysterious tangle of mathematical rules for computing apparently arbitrarily chosen numerical functions. At first sight, then, a treatise on the Logical Foundations of Probability raises hopes that it will be a guide to clarity in these matters. These hopes are strengthened if the reader remembers that the author, Professor Rudolph Carnap of the University of Chicago, is noted for his thesis that philosophy is the study of (...) the logic of science. On the other hand, a first glance into this book may discourage a reader who, though familiar with statistics, is not familiar with modern logic and its notation. For this reason particularly I shall try to give an account of this book that will enable the interested student to form some opinion of its usefulness to him. (shrink)

The received view of implicit bias holds that it is associative and unreflective. Recently, the received view has been challenged. Some argue that implicit bias is not predicated on “any” associative process, but it is unreflective. These arguments rely, in part, on debiasing experiments. They proceed as follows. If implicit bias is associative and unreflective, then certain experimental manipulations cannot change implicitly biased behavior. However, these manipulations can change such behavior. So, implicit bias is not associative and unreflective. This paper (...) finds philosophical and empirical problems with that argument. When the problems are solved, the conclusion is not quite right: implicit bias is not necessarily unreflective, but it seems to be associative. Further, the paper shows that even if legitimate non-associative interventions on implicit bias exist, then both the received view and its recent contender would be false. In their stead would be interactionism or minimalism about implicit bias. (shrink)

This paper responds to Terry Horgan’s recent critique of Bayesian formal epistemology. I argue that each of Horgan’s criticisms misses its mark when Bayesianism is viewed as putting forward an inductive logic of confidences. Along the way, I explore the nature, scope, and limits of a defensible brand of Bayesianism.

This paper develops axiomatic foundations for a probabilistic-interventionist theory of causal strength. Transferring methods from Bayesian confirmation theory, I proceed in three steps: I develop a framework for defining and comparing measures of causal strength; I argue that no single measure can satisfy all natural constraints; I prove two representation theorems for popular measures of causal strength: Pearl's causal effect measure and Eells' difference measure. In other words, I demonstrate these two measures can be derived from a set of plausible (...) adequacy conditions. The paper concludes by sketching future research avenues. (shrink)

It is well known that Rudolf Carnap’s original system of inductive logic failed to provide an adequate account of analogical reasoning. Since this problem was identified, there has been no shortage of proposals for how to incorporate analogy into inductive inference. Most alternatives to Carnap’s system, unlike his original one, have not been derived from first principles; this makes it to some extent unclear what the epistemic situations are to which they apply. This paper derives a new analogical inductive logic (...) from a set of axioms which extend Carnap’s postulates in a natural way. The key insights come from Bruno de Finetti’s ideas about analogy. The axioms of the new system capture epistemic conditions that call for a strong kind of analogical reasoning. The new system has a number of merits, but is also subject to limitations. I shall discuss both, together with some possible ways to generalize the approach taken in this paper. (shrink)

Motivated by problems that arise in computing degrees of belief, we consider the problem of computing asymptotic conditional probabilities for first-order sentences. Given first-order sentences φ and θ, we consider the structures with domain {1,..., N} that satisfy θ, and compute the fraction of them in which φ is true. We then consider what happens to this fraction as N gets large. This extends the work on 0-1 laws that considers the limiting probability of first-order sentences, by considering asymptotic conditional (...) probabilities. As shown by Liogon'kii [24], if there is a non-unary predicate symbol in the vocabulary, asymptotic conditional probabilities do not always exist. We extend this result to show that asymptotic conditional probabilities do not always exist for any reasonable notion of limit. Liogon'kii also showed that the problem of deciding whether the limit exists is undecidable. We analyze the complexity of three problems with respect to this limit: deciding whether it is well-defined, whether it exists, and whether it lies in some nontrivial interval. Matching upper and lower bounds are given for all three problems, showing them to be highly undecidable. (shrink)

Popper's writings cover a remarkably wide range of subjects. The spectrum runs from Plato's theory of politics to the foundations of quantum mechanics. Yet even amidst this variety the philosophy of probability occupies a prominent place. David Miller once pointed out to me that more than half of Popper's The Logic of Scientific Discovery is taken up with discussions of probability. I checked this claim using the 1972 6th revised impression of The Logic of Scientific Discovery , and found that (...) of the approximately 450 pages of text, approximately 250 are to do with probability. Thus Miller's claim is amply justified. It seems indeed that the philosophy of probability was one of Popper's favourite subjects, and, as we shall see, Popper certainly enriched the field with several striking innovations. In this area, as in others, Popper held very definite views, and criticized his opponents in no uncertain terms. Popper was an objectivist and anti-Bayesian, and his criticisms were directed against subjectivism and Bayesianism. (shrink)

Akrasia is both an intentional and an irrational phenomenon. These two characteristics can be reconciled by a careful reconstruction of practical reasoning. I undertake this task along Davidsonian lines, arguing against his critics that the notion of unconditional judgment is the key to an adequate account of akrasia. Unless akrasia is conceived as a failure of the agent to form an unconditional judgment that conforms to her best judgment "all things considered," the intentionality of akrasia is lost. Likewise, I show (...) how practical and theoretical reasoning concur in the production of action, and why akrasia is a problem for the philosophy of action before being a problem for moral philosophy. (shrink)

Dans laScience de la logiqueet dans l’Encyclopédie des sciences philosophiques,Hegel reconstruit la philosophie critique de Kant en développant i) une logique transcendantale dans laScience de la logiqueet dans laPhilosophie de la nature; ii) une conception pragmatique de l’a priori; et iii) une caractéristique-clé de l’usage du verbe «réaliser» en relation avec les concepts et les principes. Chacun de ces trois éléments constitue un aspect central de la sémantique spécifiquement cognitive de Hegel, que celui-ci développe, en partant de la thèse kantienne (...) de la référence cognitive singulière, en un réalisme pragmatique systématique. (shrink)

It is known that evidential support, on the Bayesian definition of this notion, is intransitive. According to some, however, the Bayesian definition is too weak to be materially adequate. This paper investigates whether evidential support is transitive on some plausible probabilistic strengthening of that definition. It is shown that the answer is negative. In fact, it will appear that even under conditions under which the Bayesian notion of evidential support is transitive, the most plausible candidate strengthenings are not.

This article documents the history of the Allais paradox, and shows that underneath the many discussions of the various protagonists lay different, irreconcilable epistemological positions. Savage, like his mentor von Neumann and similar to economist Friedman, worked from an epistemology of generalized characterizations. Allais, on the other hand, like economists Samuelson and Baumol, started from an epistemology of exact descriptions in which every axiom was an empirical claim that could be refuted directly by observations. As a result, the two sides (...) failed to find a common ground. Only a few decades later was the now so-called Allais paradox rediscovered as an important precursor when a new behavioural economic subdiscipline started to adopt the epistemology of exact descriptions and its accompanying falsifications of rational choice theory. (shrink)

This paper explicates and argues for the thesis that individual rational judgment, of the kind required for rational justification in non-formal, substantive domains – i.e. in empirical knowledge or in morals (both ethics and justice) – is in fundamental part socially and historically based, although these social and historical aspects of rational justification are consistent with realism about the objects of empirical knowledge and with strict objectivity about basic moral principles. The central thesis is that, to judge fully rationally that (...) one judges – in ways which provide rational justification of one’s judgment about any substantive matter – requires recognising one’s inherent fallibility and consequently also recognising our mutual interdependence for assessing our own and each others’ judgments and their justification. This explication provides a pragmatic account of rational justification in substantive domains which puts paid to the traditional distinction, still influential today, between ‘rational’ and ‘historical’ knowledge. (Note: This paper is a counterpart to Westphal 2011b; each paper contains substantial material not included in the other.). (shrink)

The apparent implications of the latest findings of the life sciences for our freedom and autonomy are both exciting and controversial: They undermine a common view of human freedom: a fundamentally Cartesian view. A superior account of our freedom was developed by Kant and Hegel. Key features of Hegel's account show that we can expect from the life sciences further insights into the biological basis of our freedom and autonomy, but not their repudiation. I begin with basic features of Cartesian (...) self-transparency (II) and then review three findings of contemporary life sciences (III). I then detail key features of Hegel's anti-Cartesianism (IV), in order to formulate the basic question about our freedom posed by the claim that biology explains away human freedom (V). I criticize this biological determinism by drawing upon Hegel's account of human freedom as autonomy (VI), and comment briefly on biologism in moral theory (VII). (shrink)

Les Œuvres respectives de Piaget et de Kuhn sont des études sur l'évolution d'un certain type de connaissance: la connaissance enfantine chez Piaget, la physique et la chimie chez Kuhn. Dans les deux cas, on essaie d'analyser les facteurs qui déterminent les changements des contenus de la connaissance, et les relations qui existent entre ces divers contenus successifs. Il nous semble qu'une comparaison de ces deux études révèle des convergences intéressantes pour la théorie de la connaissance.