The plausible reasoning class (called the JSM-reasoning in honour of John Stuart Mill) is described. It implements interaction of three forms of non-deductive procedures  induction, analogy and abduction. Empirical induction in the JSM-reasoning is the basis for generation of hypotheses on causal relations (determinants of social behaviour). Inference by analogy means that predictions about previously unknown properties of objects (individual’s behaviour) are inferred from causal relations. Abductive inference is performed to check on the explanatory adequacy (...) of generated hypotheses. To recognize rationality of respondents’ opinion deductive inference is used. Plausible reasoning, semantics of argumentation logic and deductive recognition of opinion rationality represent logical tool for cognitive sociology problems. (shrink)

2014 Reprint of 1954 American Edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. This two volume classic comprises two titles: "Patterns of Plausible Inference" and "Induction and Analogy in Mathematics." This is a guide to the practical art of plausible reasoning, particularly in mathematics, but also in every field of human activity. Using mathematics as the example par excellence, Polya shows how even the most rigorous deductive discipline is heavily dependent on techniques (...) of guessing, inductive reasoning, and reasoning by analogy. In solving a problem, the answer must be guessed at before a proof can be given, and guesses are usually made from a knowledge of facts, experience, and hunches. The truly creative mathematician must be a good guesser first and a good prover afterward; many important theorems have been guessed but no proved until much later. In the same way, solutions to problems can be guessed, and a god guesser is much more likely to find a correct solution. This work might have been called "How to Become a Good Guesser."-From the Dust Jacket. (shrink)

Here the author of How to Solve It explains how to become a "good guesser." Marked by G. Polya's simple, energetic prose and use of clever examples from a wide range of human activities, this two-volume work explores techniques of guessing, inductive reasoning, and reasoning by analogy, and the role they play in the most rigorous of deductive disciplines.

This article evaluates whether Rescher's rules for plausible reasoning or other rules used in artificial intelligence for "confidence factors" can be extended to deal with arguments where the linked-convergent distinction is important.

Despite overwhelming evidence suggesting that quantifier scope is a phenomenon that must be treated at the pragmatic level, most computational treatments of scope ambiguities have thus far been a collection of syntactically motivated preference rules. This might be in part due to the prevailing wisdom that a commonsense inferencing strategy would require the storage of and reasoning with a vast amount of background knowledge. In this paper we hope to demonstrate that the challenge in developing a commonsense inferencing strategy (...) is in the discovery of the relevant commonsense data and in a proper formulation of the inferencing strategy itself, and that a massive amount of background knowledge is not always required. In particular, we present a very effective procedure for resolving quantifier scope ambiguities at the pragmatic level using simple quantitative data that is readily available in most database environments. (shrink)

Plausible (eikotic) reasoning known from ancient Greek (late Academic) skeptical philosophy is shown to be a clear notion that can be analyzed by argumentation methods, and that is important for argumentation studies. It is shown how there is a continuous thread running from the Sophists to the skeptical philosopher Carneades, through remarks of Locke and Bentham on the subject, to recent research in artificial intelligence. Eleven characteristics of plausible reasoning are specified by analyzing key examples of (...) it recognized as important in ancient Greek skeptical philosophy using an artificial intelligence model called the Carneades Argumentation System (CAS). By applying CAS to ancient examples it is shown how plausible reasoning is especially useful for gaining a better understanding of evidential reasoning in law, and argued that it can also be applied to everyday argumentation. Our analysis of the snake and rope example of Carneades is also used to point out some ways CAS needs to be extended if it is to more fully model the views of this ancient philosopher on argumentation. (shrink)

Although the work consists of sixteen connected chapters, there is a difference of motivation that led to the book being published in two volumes. The first eleven chapters, comprising Volume I, attempt to teach good guessing through examples. The remaining chapters, in Volume II, deal with general principles of plausible reasoning.

We provide a general framework for constructing natural consequence relations for paraconsistent and plausible nonmonotonic reasoning. The framework is based on preferential systems whose preferences are based on the satisfaction of formulas in models. We show that these natural preferential In the research on paraconsistency, preferential systems systems that were originally designed for for paraconsistent reasoning fulfill a key condition (stopperedness or smoothness) from the theoretical research of nonmonotonic reasoning. Consequently, the nonmonotonic consequence relations that they (...) induce fulfill the desired conditions of plausible consequence relations. Hence our framework encompasses different types of preferential systems that were developed from different motivations of paraconsistent reasoning and non-monotonic reasoning, and reveals an important link between them. (shrink)

This paper studies a class of infinite-valued predicate logics. A sufficient condition for axiomatizability of logics from that class is given.

The book can also be used as an excellent text for graduate-level courses in AI, operations research, or applied probability.

I comment on two analyses of the Simonshaven case: one by Prakken (2019), based on arguments, and the other by van Koppen and Mackor (2019), based on scenarios (or stories, narratives). I argue that both analyses lack a clear account of proof beyond a reasonable doubt because they lack a clear account of the notion of plausibility. To illustrate this point, I focus on the defense argument during the appeal trial and show that both analyses face difficulties in modeling key (...) features of this argument. (shrink)

Recent work by Marchisella exposed a gap in the literature on causal non-monotonic reasoning: what is needed is an approach whose primary motivation is the formal representation of the way in which humans typically reason with cause and effect. We extend the work of Marchisella, and propose a new type of causal non-monotonic reasoning, _Plausible Causal Reasoning_, which fills the gap in the literature. We propose some new principles which help characterise Plausible Causal Reasoning, and suggest (...) a family of non-monotonic logics which provides a suitable starting point for its formalisation. (shrink)

In their unifying theory to model uncertainty, Friedman and Halpern (1995–2003) applied plausibility measures to default reasoning satisfying certain sets of axioms. They proposed a distinctive condition for plausibility measures that characterizes “qualitative” reasoning (as contrasted with probabilistic reasoning). A similar and similarly fundamental, but more general and thus stronger condition was independently suggested in the context of “basic” entrenchment-based belief revision by Rott (1996–2003). The present paper analyzes the relation between the two approaches to formalizing basic (...) notions of plausibility as used in qualitative default reasoning. While neither approach is a special case of the other, translations can be found that elucidate their relationship. I argue that Rott’s notion of plausibility allows for a more modular set-up and has a better philosophical motivation than that of Friedman and Halpern. (shrink)

In his important recent book Schroeder proposes a Humean theory of reasons that he calls hypotheticalism. His rigourous account of the weight of reasons is crucial to his theory, both as an element of the theory and constituting his defence to powerful standard objections to Humean theories of reasons. In this paper I examine that rigourous account and show it to face problems of vacuity and consonance. There are technical resources that may be brought to bear on the problem of (...) vacuity but implementation is not simple and philosophical motivation a further difficulty. Even supposing vacuity is fixed, the problems of consonance bring to light a different obstruction lying in Schroeder’s path. There is a difference between the general weighing of reasons and the context specificity of the correct placing of weight on them in deliberation and this difference cannot be fixed by the resources in the account. For these reasons we are still waiting for a plausible Humean theory of reasons. (shrink)

This paper addresses the two extensional objections to the Humean Theory of Reasons—that it allows for too many reasons, and that it allows for too few. Although I won’t argue so here, manyof the other objections to the Humean Theoryof Reasons turn on assuming that it cannot successfully deal with these two objections.1 What I will argue, is that the force of the too many and the too few objections to the Humean Theorydepend on whether we assume that Humeans are (...) committed to a thesis about the weight of reasons—one I call Proportionalism. In particular, I’ll show how a version of the Humean Theorythat rejects Proportionalism can reasonablyhope to escape both the too many and the too few objections. This will constitute my defense of this version of the Humean Theory. But then, separately, I will argue that this defense of the Humean Theoryis not ad hoc. I’ll argue that Humeans have no reason to accept Proportionalism in the first place. Or at least, no weightyone. There are three parts to the paper. In Part 1 we introduce the Humean Theoryand the too few reasons objection. I’ll first layout the objection, and then layout the basis for a response on behalf of myfavored version of the Humean Theory. There will be an obvious objection to my defense— but it will turn out to depend on the assumption of Proportionalism. This will constitute myargument that the susceptibilityof the Humean Theoryto.. (shrink)

This paper has two goals. First, we develop frameworks for logical systems which are able to reflect not only non-monotonic patterns of reasoning, but also paraconsistent reasoning. Our second goal is to have a better understanding of the conditions that a useful relation for nonmonotonic reasoning should satisfy. For this we consider a sequence of generalizations of the pioneering works of Gabbay, Kraus, Lehmann, Magidor and Makinson. These generalizations allow the use of monotonic nonclassical logics as the (...) underlying logic upon which nonmonotonic reasoning may be based. Our sequence of frameworks culminates in what we call plausible, nonmonotonic, multiple-conclusion consequences relations . Our study yields intuitive justifications for conditions that have been proposed in previous frameworks and also clarifies the connections among some of these systems. In addition, we present a general method for constructing plausible nonmonotonic relations. This method is based on a multiple-valued semantics, and on Shoham's idea of preferential models. (shrink)

A common reason for giving research participants post-trial access to the trial intervention appeals to reciprocity, the principle, stated most generally, that if one person benefits a second, the second should reciprocate: benefit the first in return. Many authors consider it obvious that reciprocity supports PTA. Yet their reciprocity principles differ, with many authors apparently unaware of alternative versions. This article is the first to gather the range of reciprocity principles. It finds that: most are false. The most plausible (...) principle, which is also problematic, applies only when participants experience significant net risks or burdens. Seldom does reciprocity support PTA for participants or give researchers stronger reason to benefit participants than equally needy non-participants. Reciprocity fails to explain the common view that it is bad when participants in a successful trial have benefited from the trial intervention but lack PTA to it. (shrink)

I propose a construal of aesthetic value that gives us reason to emphasize some aesthetic practices over others. This construal rests on the existence of a central aesthetic value, namely apprehension-testing intricacy within an appropriate domain. I address three objections: the objection that asks how an aesthetic value based on intricacy can account for the value of minimalism; the objection that asks about the difference between intricacy within a medium and intricacy between media; and the objection that asks about the (...) danger of a regress. I then say that, although this central aesthetic value can in principle allow us to adjudicate between aesthetic practices, we have epistemic limits (about the potential of certain artistic domains to allow for apprehension-testing intricacy) that prevent adjudication in some cases. Even if there is a difference between the vastness of the potential-intricacy-fields somewhere down the line, it is too far for us to see. (shrink)

In criminal trials, judges or jurors have to decide whether the facts described in the indictment are proven beyond a reasonable doubt. However, these decision-makers cannot always imagine every relevant sequence of events—there may be unconceived alternatives. The possibility of unconceived alternatives is an overlooked source of reasonable doubt. I argue that decision-makers should not consider the defendant’s guilt proven if they have good reasons to believe that plausible, unconceived scenarios exist. I explore this thesis through the lens of (...) the two most influential accounts of rational criminal proof—Bayesian and explanation-based approaches. I draw on related ideas from the philosophy of science to show why and when unconceived alternatives lead to reasonable doubt on either account. (shrink)