The study of presumptions has intensified in argumentation theory over the last years. Although scholars put forward different accounts, they mostly agree that presumptions can be studied in deliberative and epistemic contexts, have distinct contextual functions, and promote different kinds of goals. Accordingly, there are “practical” and “cognitive” presumptions. In this paper, I show that the differences between practical and cognitive presumptions go far beyond contextual considerations. The central aim is to explore Nicholas Rescher’s contention that both types of presumptions (...) have a closely analogous pragmatic function, i.e., that practical and cognitive presumptions are made to avoid greater harm in circumstances of epistemic uncertainty. By comparing schemes of practical and cognitive reasoning, I show that Rescher’s contention requires qualifications. Moreover, not only do practical and cognitive presumptions have distinct pragmatic functions, but they also perform different dialogical functions and, in some circumstances, cannot be defeated by the same kinds of evidence. Hence, I conclude that the two classes of presumptions merit distinct treatment in argumentation theory. (shrink)

Traditionally, a presumption is a dialogically privileged, yet defeasible proposition that allocates the burden of proof to a party who challenges it. This paper investigates the strength of presumptions. First, it explains how ‘strength’ contributes to defining the concept of presumption. Second, it provides an overview of (contextual, justificatory, and deontic) factors determining a presumption’s strength. Finally, it analyses the predominant view that defines strength in terms of the Challenger’s burden of proof: the stronger (weaker) the presumptionp, the more (less) (...) difficult it is to prove non-p. I argue that the latter proposal applies only to practical presumptions, and that strength is conceived differently for cognitive presumptions. (shrink)

The question of who has the burden of proof is often important in practice. We must frequently make decisions and act on the basis not of conclusive evidence but of what is reasonable to presume true. Consequently, it happens that a given practical question must be solved by referring to principles that explicitly or implicitly determine, at least partly, where the burden of proof should rest. In this essay, I consider the role of the logic of the burden of proof (...) in a debate on global justice. In particular, I ask how the logic of the burden of proof is seen by those who defend conservative positions in a debate and deny our obligations to reduce poverty beyond borders. I argue that defenders of conservative positions tend to shift the burden of proof in an unjustified way. (shrink)

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)