Paul Bartha

By Parallel Reasoning is the first comprehensive philosophical examination of analogical reasoning in more than forty years designed to formulate and justify standards for the critical evaluation of analogical arguments. It proposes a normative theory with special focus on the use of analogies in mathematics and science. In recent decades, research on analogy has been dominated by computational theories whose objective has been to model analogical reasoning as a psychological process. These theories have devoted little attention to normative questions. In this book Bartha proposes that a good analogical argument must articulate a clear relationship that is capable of generalization. This idea leads to a set of distinct models for the critical analysis of prominent forms of analogical argument. The same core principle makes it possible to relate analogical reasoning to norms and values of scientific practice. Reasoning by analogy is justified because it strikes an optimal balance between conservative values, such as simplicity and coherence, and progressive values, such as fruitfulness and theoretical unification. Analogical arguments are also justified by appeal to symmetry--like cases are to be treated alike. In elaborating the connection between analogy and these broad epistemic principles, By Parallel Reasoning offers a novel contribution to explaining how analogies can play an important role in the confirmation of scientific hypotheses.

Among recent objections to Pascal's Wager, two are especially compelling. The first is that decision theory, and specifically the requirement of maximizing expected utility, is incompatible with infinite utility values. The second is that even if infinite utility values are admitted, the argument of the Wager is invalid provided that we allow mixed strategies. Furthermore, Hájek has shown that reformulations of Pascal's Wager that address these criticisms inevitably lead to arguments that are philosophically unsatisfying and historically unfaithful. Both the objections and Hájek's philosophical worries disappear, however, if we represent our preferences using relative utilities rather than a one-place utility function. Relative utilities provide a conservative way to make sense of infinite value that preserves the familiar equation of rationality with the maximization of expected utility. They also provide a means of investigating a broader class of problems related to the Wager.

The Pasadena game invented by Nover and Hájek raises a number of challenges for decision theory. The basic problem is how the game should be evaluated: it has no expectation and hence no well-defined value. Easwaran has shown that the Pasadena game does have a weak expectation, raising the possibility that we can eliminate the value gap by requiring agents to value gambles at their weak expectations. In this paper, I first prove a negative result: there are gambles like the Pasadena game that do not even have a weak expectation. Hence, problematic value gaps remain even if decision theory is extended to take in weak expectations. There is a further challenge: the existence of a ‘value gap’ in the Pasadena game seems to make decision theory inapplicable in a number of cases where the right choice is obvious. The positive contribution of the paper is a theory of ‘relative utilities’, an extension of decision theory that lets us make comparative judgements even among gambles that have no well-defined value.

Qu'est-ce qui explique l'unité d'une substance leibnizienne, au-dessus des attributs compris dans sa notion individuelle complète? C'est une question commune dans la littérature sur la notion de la substance chez Leibniz. Cet article soutient qu'elle n'admette pas de réponse consistante dans le système leibnizien. Premièrement, je discute la manière dans laquelle Leibniz a essayé de répondre à la question en „rehabillitant" a les formes substantielles des scholastiques. Puis je cherche à montrer que ça lui a ammené à une conception composée de la nature de la substance, une position similaire de quelques façons à celle de Duns Scotus. Cette conception composée, cependant, n'est pas soutenable étant donné que Leibniz a rejeté la „distinction formelle" de Scotus.

De Finetti would claim that we can make sense of a draw in which each positive integer has equal probability of winning. This requires a uniform probability distribution over the natural numbers, violating countable additivity. Countable additivity thus appears not to be a fundamental constraint on subjective probability. It does, however, seem mandated by Dutch Book arguments similar to those that support the other axioms of the probability calculus as compulsory for subjective interpretations. These two lines of reasoning can be reconciled through a slight generalization of the Dutch Book framework. Countable additivity may indeed be abandoned for de Finetti's lottery, but this poses no serious threat to its adoption in most applications of subjective probability. Introduction The de Finetti lottery Two objections to equiprobability 3.1 The ‘No random mechanism’ argument 3.2 The Dutch Book argument Equiprobability and relative betting quotients The re-labelling paradox 5.1 The paradox 5.2 Resolution: from symmetry to relative probability Beyond the de Finetti lottery.

How can self-locating propositions be integrated into normal patterns of belief revision? Puzzles such as Sleeping Beauty seem to show that such propositions lead to violation of ordinary principles for reasoning with subjective probability, such as Conditionalization and Reflection. I show that sophisticated forms of Conditionalization and Reflection are not only compatible with self-locating propositions, but also indispensable in understanding how they can function as evidence in Sleeping Beauty and similar cases.