In good form : arguing for epistemic norms of credence

The main topic of the book is how to argue for formal epistemic norms of credence. The author advocates formal justificational pluralism, suggesting that it is reasonable to use various formal tools, e.g. different "scoring rules", in arguments for synchronic and diachronic norms. The author first examines various occasions on which modern formal epistemology fails to live up to its "formal" label. Among the topics considered next are: the Dutch Book Theorem and Arguments (which fails according to the author), a novel version of the Principal Principle, and a constructive approach to higher order probabilities. The author argues then that the best method for dealing with various belief update problems is that of minimizing inverse relative entropy, and defends the claim that for evaluating an agent’s credal state at a single moment the Brier Score seems to be the way to go

Review of risk and uncertainty concepts for climate change assessments including human dimensions

Soumis à Philosophy StudiesThis paper discusses aspects of risk and uncertainty relevant in an interdisciplinary assessment of climate change policy. It opposes not only the objective approach versus the subjective approach, but also situations when precise probabilities are well founded versus situations of broader forms of error such as Knightian or deep uncertainty, incompleteness, vagueness. Additional human and social dimensions of ignorance: strategic uncertainties, surprises, values diversity, and taboos, are discussed. We argue that the broader forms of error affect all sciences, including those studying Nature. For these aspects the IPCC guidance notes provides an interdisciplinary unified approach on risk and uncertainty. This is a significant advance from a simple multidisciplinary justaposition of approaches. However, these guidance notes are not universal, they mostly omit the human and social dimensions of ignorance.Ce papier discute les divers aspects du risque et de l'incertitude pertinents dans le cadre de l'évaluation interdisciplinaire des politiques climatiques. Il marque non seulement l'opposition entre l'approche objective (qui voit les probabilités comme des degrés de vérité) et l'approche bayésienne (qui les voit comme des degrés de certitude), mais encore l'opposition entre les situations de risque (quand on dispose de probabilités précises et bien fondées) et les situations d'incertitude (des formes d'ignorance plus générale, comme l'incertitude au sens de Knight, l'incomplétude ou le vague). L'évolution des directives IPCC sur le risque et l'incertitude entre le troisième et le quatrième rapport peuvent se lire comme un mouvement s'écartant de la position objectiviste et probabiliste, pour inclure des aspects plus complexes de l'incertitude. Cependant, il reste encore des dimensions humaines comme l'ignorance stratégique, les surprises, les aspects métaphysiques, les taboos et l'incertitude épistémique qui manquent dans les directives IPCC

Conditional sentences: truth conditions and probability

This dissertation supports a partial semantics for conditional statements, which wants to be a middle way between the idea conditionals have not truth conditions and that they always are true or false. Adams showed an important intuitive result, called “Equation”, according to which the probability of a conditional is its conditional probability. In a first moment the Equation was satisfied by Stalnaker’s theory, but Lewis 1975 showed—by the Triviality Result—the incompatibility between the assumption that the probability of a proposition is the probability it is true and the Equation. Consequently, supporting Stalnaker’s semantic means to reject Adams’ logic—and vice versa. In front of Lewis’ result, Adams concluded conditionals do not have truth conditions, suggesting a non-propositional view. Contrary, Stalnaker proposed to consider conditional sentences as standard propositions, giving up the Equation such as a general satisfied principle. With the intent to hold the Equation—and Adams’ logic—without denying conditionals have any kind of truth conditions, the dissertation analyzes Alberto Mura’s proposal—the Theory of Hypervaluated Trievents. It concerns a semantic built on de Finetti’s three-valued logic with the intent to avoid Lewis’ result, incorporating Adams’ logic and extending it to every trievent. Demonstrating that every trievent is simple, Mura tried to provide a theory able to deal with both simple and compound conditionals.</br

Pascal's wager

Pascal's Wager, discussed in his Pensées, has provoked discussion and strong views ever since its publication. In it, he proposes: Either God is or he is not. But to which view shall we be inclined? Reason cannot decide this question.ⁱ In this thesis I hope to make a contribution to the ongoing debate by setting Pascal's Wager into a modern decision-making context, providing a taxonomy of objections to the Wager and developing a critical framework which can be used to systematically examine each category in turn to see whether an objection holds. I will also present a new approach to handling 'mixed' strategies, as suggested by Alan Hájek and others, which uses a heuristic model of our perception of infinite rewards. I hold that Pascal's remedy for the unbeliever is a therapeutic response which is entirely in line with modern psychological practice and should not offend moral sensitivities, because it is purely an experiment to see whether faith can naturally arise once the objections are temporarily set aside. I argue that Pascal's Wager needs to be seen as an exercise in personal risk management and that Pascal anticipated both modern decision theory and the associated psychology of how we make choices in formulating his Wager. I suggest that if we understand it in this light, employing the critical toolkit that I assemble, then Pascal's Wager holds against all current objections. ⁱ Blaise Pascal, Pensées, trans. A. J. Krailsheimer (London: Penguin, 1995). 122. L41