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)

According to John D. Norton's Material Theory of Induction, all reasonable inductive inferences are justified in virtue of background knowledge about local uniformities in nature. These local uniformities indicate that our samples are likely to be representative of our target population in our inductions. However, a variety of critics have noted that there are many circumstances in which induction seems to be reasonable, yet such background knowledge is apparently absent. I call such absences ‘the frontiers of science', where background scientific (...) theories do not provide information about such local uniformities. I argue that the Material Theory of Induction can be reconciled with our intuitions in favour of these inductions. I adapt an attempted justification of induction in general, the Combinatoric Justification of Induction, into a more modest rationalisation at the less foundational level that the critics discuss. Subject to a number of conditions, we can extrapolate from large samples using our knowledge of facts about the minimum proportions of representative subsets of finite sets. I also discuss some of Norton's own criticisms of his theory and argue that he is overly pessimistic. I conclude that Norton's theory at least performs well at the frontiers of science. (shrink)

_ Source: _Page Count 13 A promising response to the threat of external world skepticism involves arguing that our commonsense view of the world best explains the sensory experiences that we have. Since our commonsense view of the world best explains our evidence, we are justified in accepting this commonsense view of the world. Despite the plausibility of this Explanationist Response, it has recently come under attack. James Beebe has argued that only a version of the Explanationist Response that provides (...) an a priori justification of inference to the best explanation can hope to respond to two serious objections. Additionally, he has argued that providing such an a priori justification requires an acceptable account of a priori probability and that it is unclear whether such an account can be developed. In this paper I argue that Beebe fails to provide adequate support for either of these claims. (shrink)

This paper shows that during the first half of the 1960s The Journal of Philosophy quickly moved from publishing work in diverse philosophical traditions to, essentially, only publishing analytic philosophy. Further, the changes at the journal are shown, with the help of previous work on the journals Mind and The Philosophical Review, to be part of a pattern involving generalist philosophy journals in Britain and America during the period 1925-1969. The pattern is one in which journals controlled by analytic philosophers (...) systematically promote a form of critical philosophy and marginalise rival approaches to philosophy. This pattern, it is argued, helps to explain the growing dominance of analytic philosophy during the twentieth century and allows characterising this form of philosophy as, at least during 1925-1969, a sectarian form of critical philosophy. (shrink)

In 1947 Donald Cary Williams claimed in The Ground of Induction to have solved the Humean problem of induction, by means of an adaptation of reasoning first advanced by Bernoulli in 1713. Later on David Stove defended and improved upon Williams’ argument in The Rational- ity of Induction (1986). We call this proposed solution of induction the ‘Williams-Stove sampling thesis’. There has been no lack of objections raised to the sampling thesis, and it has not been widely accepted. In our (...) opinion, though, none of these objections has the slightest force, and, moreover, the sampling thesis is undoubtedly true. What we will argue in this paper is that one particular objection that has been raised on numerous occasions is misguided. This concerns the randomness of the sample on which the inductive extrapolation is based. (shrink)