We review the definition of the Full Bayesian Significance Test (FBST), and summarize its main statistical and epistemological characteristics. We review also the Abstract Belief Calculus (ABC) of Darwiche and Ginsberg, and use it to analyze the FBST’s value of evidence. This analysis helps us understand the FBST properties and interpretation. The definition of value of evidence against a sharp hypothesis, in the FBST setup, was motivated by applications of Bayesian statistical reasoning to legal matters where the sharp hypotheses were (...) defendants statements, to be judged according to the Onus Probandi juridical principle. (shrink)

This paper explores two persistent questions in the literature on presumptions: the place and the nature of presumptions in law and legal argumentation. These questions were originally raised by James Bradley Thayer, one of the masters of the Law of Evidence and the author of the classic chapter devoted this subject in A preliminary treatise on Evidence. Like Thayer, I believe that these questions deserve attention. First the paper shows that the connection between presumptions and argumentation is a constant feature (...) in the literature on presumptions, since its foundation in the Middle Ages to modern times. James Bradley Thayer was probably the last jurist who clearly saw that presumptions belong to argumentation. Second, the paper examines two sources of controversy in the language of presumptions. First, “presumption” is an ambiguous word in the legal discourse. As a result, it is almost impossible to provide a clear and succinct answer to the question “What is a presumption?”. Second, there are at least four reconstructions of the concept of presumption whose merits and shortcomings are relevant to explore. The analysis presented here may be of interest for legal and non-legal scholars and, hopefully, it may help to shed light on the possibilities and limits of an interdisciplinary dialogue about presumptions. (shrink)

This paper traces the evolution of the concept of presumption from a subordinate part of the Roman law to a central feature of legal disputations in medieval law. Special attention will be given to the second edition of the Libellus Pylei Disputato rius by Pilius of Medicina, and to the anonymous Tractatus de Praesumptionibus. My analysis will emphasize elements of these developments useful in the renewed discussion about the role of presumptions in argumentation stimulate d particularly by Richard Gaskins' Burdens (...) of Proof in Modern Discourse, highlighting the paradigmatic significance of rhetorical manipulations of burdens of proof in legal reasoning. (shrink)

In this paper, the relationship between the e-value of a complex hypothesis, H, and those of its constituent elementary hypotheses, Hj, j = 1… k, is analyzed, in the independent setup. The e-value of a hypothesis H, ev, is a Bayesian epistemic, credibility or truth value defined under the Full Bayesian Significance Testing mathematical apparatus. The questions addressed concern the important issue of how the truth value of H, and the truth function of the corresponding FBST structure M, relate to (...) the truth values of its elementary constituents, Hj, and to the truth functions of their corresponding FBST structures Mj, respectively. (shrink)

Douglas Walton has been right in calling us to attend to the pragmatics of argument. He has, however, also insisted that arguments should be understood and assessed by considering the functions they perform; and from this, I dissent. Argument has no determinable function in the sense Walton needs, and even if it did, that function would not ground norms for argumentative practice. As an alternative to a functional theory of argumentative pragmatics, I propose a design view, which draws attention to (...) the way participants strategically undertake and impose norms on themselves in order for their arguments to have force. (shrink)

How do Dutch people let each other know that they disagree? What do they say when they want to resolve their difference of opinion by way of an argumentative discussion? In what way do they convey that they are convinced by each other’s argumentation? How do they criticize each other’s argumentative moves? Which words and expressions do they use in these endeavors? By answering these questions this short essay provides a brief inventory of the language of argumentation in Dutch.

We show how the Full Bayesian Significance Test (FBST) can be used as a model selection criterion. The FBST was presented by Pereira and Stern as a coherent Bayesian significance test. Key Words: Bayesian test; Evidence; Global optimization; Information; Model selection; Numerical integration; Posterior density; Precise hypothesis; Regularization. AMS: 62A15; 62F15; 62H15.

In this paper epistemological, ontological and sociological questions concerning the statistical significance of sharp hypotheses in scientific research are investigated within the framework provided by Cognitive Constructivism and the FBST (Full Bayesian Significance Test). The constructivist framework is contrasted with the traditional epistemological settings for orthodox Bayesian and frequentist statistics provided by Decision Theory and Falsificationism.

Is there—or rather, ought there to be—a presumption of atheism, as Antony Flew so famously argued nearly half a century ago? It is time to revisit this issue. After clarifying the concept of a presumption of atheism, I take up the evaluative question of whether there ought to be a presumption of atheism, focusing on Flew’s arguments for an affirmative answer. I conclude that Flew’s arguments, one of which rests on an analogy with the presumption of innocence, fail.

The notion of “the burden of proof” plays an important role in real-world argumentation contexts, in particular in law. It has also been given a central role in normative accounts of argumentation, and has been used to explain a range of classic argumentation fallacies. We argue that in law the goal is to make practical decisions whereas in critical discussion the goal is frequently simply to increase or decrease degree of belief in a proposition. In the latter case, it is (...) not necessarily important whether that degree of belief exceeds a particular threshold (e.g., ‘reasonable doubt’). We explore the consequences of this distinction for the role that the “burden of proof” has played in argumentation and in theories of fallacy. (shrink)

An outsider to argument theory, should she look through the rich outpouring of our recent work, might be amused to find us theorists not following our own prescriptions. We propound our ideas, but we don't always interact with each other--we don't argue. The essays by William Rehg and Robert Asen make promising start on rectifying this difficulty. I want to discuss them, first, to show how they acknowledge in exemplary fashion a pair of challenges I think we should all be (...) addressing; and next to consider their specific responses. (shrink)

Differences arise in macro-activities, such as the production of energy, food, and healthcare, where the management of these differences happens in polylogues as many actors pursue scores of positions on a variety of issues in numerous venues. Polylogues are essential to the large-scale practices that organize macro-activities but present significant challenges for argumentation theory and research. Key to the challenge is conceptualizing the variety of argumentative roles that go beyond the classic normative definition of protagonist and antagonist. A macroscope is (...) devised for identifying argumentative roles in the communicative work of organizations, and the communicative work of the network of organizations, related to the production of gas from shale in the Marcellus region of the Northeastern United States. The macroscope scaffolds a design thinking inquiry into the variety of argumentative roles in the communicative work of organizations in a polylogue and finds: innovation and entrepreneurialism in the design of organizations as devices for managing disagreement; argumentative roles as services specializing in particular aspects of argument; and networks of organizations with prominent types of specialized roles that give shape to the disagreement space around a large, complex practice. It is proposed that the varieties of argumentative roles in polylogue are not random or arbitrary but derive from more general pragmatic principles about how disagreement is organized and how methods of disagreement management emerge within communication relative to a macro-activity. (shrink)

We commonly think of presumptions as second-best inferential tools allowing us to reach conclusions, if we must, under conditions of limited information. Scholarship on the topic across the disciplines has espoused a common conception of presumptions that defines them according to their function within the decisionmaking process. This focus on the “private” face of presumptions has generated a predominantly critical and grudging view of them, perpetuated certain conceptual ambiguities, and, most important, neglected the fact that what we refer to as (...) “presumptions” have distinguishing features other than the defeasibility and burden-shifting effects associated with their use as inferential tools. When a decisionmaker gives reasons for a conclusion, the decisionmaker often cites a presumption among the reasons for that conclusion; in this guise – their “public” face – presumptions display different, and uniquely valuable, features that remain hidden if we understand them only as aids to inference. This essay both surveys recent approaches to the critical analysis of presumptions in law, philosophy, and discourse studies, and offers an account of how we might begin to think about this other, public face of presumptions. (shrink)

This paper joins the voices warning against hasty transference of legal concepts of presumption to other kinds of argumentation, especially to deliberation about future acts and policies. Comparison of the pragmatics which respectively constitute the illocutionary acts of accusing and proposing reveals important differences in the ways presumptions prompt accusers and proposers to undertake probative responsibilities and, also, points to corresponding differences in their probative duties. This comparison has theoretically important implication regarding the norms governing persuasive argumentation. The paper is (...) based on a broadly Gricean account of speech acts. (shrink)

Two answers to the question ‘how can we allocate health care resources fairly?’ are introduced and discussed. Both utilitarian and egalitarian approaches are found relevant, but both exhibit considerable theoretical and practical difficulties. Neither seems capable of solving the problem on its own. It is suggested that, for practical purposes, a version of Rawls' famous thought experiment might provide at least some enlightenment about which theoretical approach should be used to address the question.

This paper contrasts two views of the necessity to manifest the rational adequacy of argumentation. The view advanced by Ralph Johnson’s program for informal logic will be compared to one based on an account of obligations incurred in speech acts. Both views hold that arguers are commonly obliged to make it apparent that they are offering adequate support for their positions, but they differ in their accounts of the nature and scope of those obligations.