'Even the wisest of doctors are relying on scientific truths the errors of which will be recognised within a few years time,' wrote Marcel Proust a century ago. At that time most people understood the severe limitations of medicine, but today doctors are viewed as having enormous power. Medical research is seen by the public as the 'most scientific' form of scientific research (1); television p...

A critical view of the alleged significance of Belnap four-valued logic for reasoning under inconsistent and incomplete information is provided. The difficulty lies in the confusion between truth-values and information states, when reasoning about Boolean propositions. So our critique is along the lines of previous debates on the relevance of many-valued logics and especially of the extension o...

We study the problem of making decisions under partial ignorance, or partially quantified uncertainty. This problem arises in many applications in robotics and AI, and it has not yet got the attention it deserves. The traditional decision rules of decision under risk and under strict uncertainty (or complete ignorance) can naturally be extended to the more general case of decision under partial...

This paper advocates the use of non-purely probabilistic approaches to higher-order uncertainty. One of the major arguments of Bayesian probability proponents is that representing uncertainty is always decision-driven and as a consequence, uncertainty should be represented by probability. Here we argue that representing partial ignorance is not always decision-driven. Other reasoning tasks such...

If one looks at the history of mathematics, one sees periods of bursting creativity, when new ideas are being developed in a competitive and therefore very hasty spirit; and periods when people find that the ideas so recently in vogue are inexact, incoherent, possibly inconsistent; in such periods there is an urge to consolidate past achievements. I said " the history of mathematics " : but mat...

THE argument from ignorance has traditionally been classified as a fallacy, but there is growing recognition that this kind of argument can be nonfallacious in some cases. This raises a question: what kind of successful or good argument is it, in these cases? In this paper two argumentation schemes to represent the form of the argumentum ad ignorantiam are introduced. It is argued that they are...

ignorance is bliss, 'tis folly to be wise. " Thomas Gray If ignorance were bliss, there is information you would pay not to have. Hence the question is whether a rationally-behaving agent would ever do such a thing. This paper demonstrates that 1. A Bayesian agent with a proper, countably additive prior never maximizes utility by paying not to see cost-free data. 2. The definition of " cost-fre...

Much of cognition allows us to make sense of things by explaining observable evidence in terms of unobservable explanations, such as category memberships and hidden causes. Yet we must often make such explanatory inferences with incomplete evidence, where we are ignorant about some relevant facts or diagnostic features. In seven experiments, we studied how people make explanatory inferences und...

Vested interests and political agents have long opposed political or regulatory action in response to climate change by appealing to scientific uncertainty. Here we examine the effect of such contrarian talking points on the scientific community itself. We show that although scientists are trained in dealing with uncertainty, there are several psychological reasons why scientists may neverthele...