The applicability of Bayesian conditionalization in setting one’s posterior probability for a proposition, α, is limited to cases where the value of a corresponding prior probability, PPRI(α|∧E), is available, where ∧E represents one’s complete body of evidence. In order to extend probability updating to cases where the prior probabilities needed for Bayesian conditionalization are unavailable, I introduce an inference schema, defeasible conditionalization, which allows one to update one’s personal probability in a proposition by conditioning on a proposition that represents a (...) proper subset of one’s complete body of evidence. While defeasible conditionalization has wider applicability than standard Bayesian conditionalization (since it may be used when the value of a relevant prior probability, PPRI(α|∧E), is unavailable), there are circumstances under which some instances of defeasible conditionalization are unreasonable. To address this difficulty, I outline the conditions under which instances of defeasible conditionalization are defeated. To conclude the article, I suggest that the prescriptions of direct inference and statistical induction can be encoded within the proposed system of probability updating, by the selection of intuitively reasonable prior probabilities. (shrink)

Writing on the justification of certain inductive inferences, the author proposes that sometimes induction is justified and that arguments to prove otherwise are not cogent. In the first part he defends the argument of D.C. Williams' The Ground of Induction that induction is justified as a matter of logic by the proportional syllogism: "The vast majority of large samples match the population, therefore (probably) this sample matches the population"). In the second part he deals with such topics as deductive logic (...) (arguing that deductive logic is not formal), the theory of logical probability, and probability and truth. (shrink)

Many necessitarians about cause and law (Armstrong 1983; Mumford 2004; Bird 2007) have argued that Humeans are unable to justify their inductive inferences, as Humean laws are nothing but the sum of their instances. In this paper I argue against these necessitarian claims. I show that Armstrong is committed to the explanatory value of Humean laws (in the form of universally quantified statements), and that contra Armstrong, brute regularities often do have genuine explanatory value. I finish with a Humean attempt (...) at a probabilistic justification of induction, but this fails due to its assumption that the proportionality syllogism is justified. Although this attempt fails, I nonetheless show that the Humean is at least as justified in reasoning inductively as Armstrong. (shrink)

It is argued that the EPR paradox cannot be resolved in the context of quantum mechanics. Bell's theorem is shown to be equivalent to a Belinfante theory of zero type. It is concluded therefore that it cannot have as wide a range of applicability in excluding Hidden Variable Theories as commonly alleged. It follows that standard quantum mechanics should not be regarded as a complete theory in Einstein's sense. Indeed, it is argued that a purely probabilistic theory cannot be the (...) basis of a comprehensive understanding of physics. An attempt is made to formulate a deterministic, local Hidden Variable Theory to account for the Bohm-Einstein thought experiment reproducing quantum mechanical predictions. (shrink)

This paper begins with a rigorous critique of David Stove''s recent bookThe Rationality of Induction. In it, Stove produced four different proofs to refute Hume''s sceptical thesis about induction. I show that Stove''s attempts to vindicate induction are unsuccessful. Three of his proofs refute theses that are not the sceptical thesis about induction at all. Stove''s fourth proof, which uses the sampling principle to justify one particular inductive inference, makes crucial use of an unstated assumption regarding randomness. Once this assumption (...) is made explicit, Hume''s thesis once more survives.The refutation of Stove''s fourth proof leads to some observations which relate Goodman''s grue paradox with randomness of a sample. I formulate a generalized version of Goodman''s grue paradox, and argue that whenever a sample, no matter how large, is drawn from a predetermined smaller interval of a population that is distributed over a larger interval, any conclusion drawn about the characteristics of the population based on the observed characteristics of the sample is fatally vulnerable to the generalized grue paradox. (shrink)

The aim of this thesis dissertation is to propose a novel position in the debate on scientific realism, modal empiricism, and to show its fruitfulness when it comes to interpreting the cognitive content of scientific theories. Modal empiricism is an empiricist position, according to which the aim of science is to produce empirically adequate theories rather than true theories. However, it suggests adopting a broader comprehension of experience than traditional versions of empiricism, through a commitment to natural modalities. Following modal (...) empiricism, there are possibilities in nature, and constraints on what is possible, and a theory is empirically adequate if it correctly delimits the range of possible experiences. The position rests on a situated and pragmatic conception of natural modalities and of empirical confrontation. We claim that it can do justice to the empirical success of science, while not falling prey to the problem of theory change that undermines scientific realism. We explain how constraints of necessity on phenomena can be known by induction, and how this modal epistemology fits with scientific practice. Finally, we claim that a commitment to natural modalities allows for a rich interpretation of the cognitive content of theories. Modal empiricism could renew some metaphysical debates within a pragmatist framework, by tying them to experience and not being constrained by realist prejudices. -/- L'objet de cette thèse est de proposer une position originale dans le débat sur le réalisme scientifique, l'empirisme modal, et d'en démontrer la fructuosité quand il s'agit de tirer des enseignements du contenu cognitif des théories scientifiques. L'empirisme modal est une position empiriste, suivant laquelle le but de la science n'est pas de produire des théories vraies, mais des théories empiriquement adéquate. Cependant, il propose d'adopter un cadre plus large que les versions traditionnelles d'empirisme pour penser l'expérience, en incorporant un engagement envers les modalités naturelles, ou l'idée qu'il y a du possible dans la nature, et des contraintes sur les possibles. Nos théories sont empiriquement adéquates si elles délimitent correctement l'étendue des expériences possibles. Cette position s'appuie sur une conception située et pragmatique des modalités naturelles et de la confrontation empirique. Nous prétendons qu'elle est à même de rendre justice au succès empirique des sciences, sans pour autant faire face au problème du changement théorique qui mine le réalisme scientifique. Nous expliquons comment les contraintes de nécessité sur les phénomènes peuvent être connues à l'issue d'une induction, et en quoi cette façon de voir s'accorde avec la pratique scientifique. Enfin, nous affirmons qu'un engagement envers les modalités naturelles offre une richesse interprétative à même de renouveler, dans un cadre pragmatiste, plus ouvert que le réalisme, certaines questions métaphysiques tout en les ramenant à l'expérience . (shrink)