This paper responds to Kauffeld’s 2009 OSSA paper, considering the adequacy of his “commitment-based” approach to “ordinary presumptive practices” to sup-ply an account of presumption fit for general application in normative theories of argument. The central issue here is whether socially-grounded presumptions are defeasible in the right sorts of ways so as to pro-duce “truth-tropic” presumptive inferences.

In this paper a theoretical definition that helps to explain how the logical structure of legal presumptions is constructed by applying the Carneades model of argumentation developed in artificial intelligence. Using this model, it is shown how presumptions work as devices used in evidentiary reasoning in law in the event of a lack of evidence to assist a chain of reasoning to move forward to prove or disprove a claim. It is shown how presumptions work as practical devices that may (...) be useful in cases in which there is insufficient evidence to prove the claim to an appropriate standard of proof. (shrink)

In this paper a theoretical definition that helps to explain how the logical structure of legal presumptions is constructed by applying the Carneades model of argumentation developed in artificial intelligence. Using this model, it is shown how presumptions work as devices used in evidentiary reasoning in law in the event of a lack of evidence to assist a chain of reasoning to move forward to prove or disprove a claim. It is shown how presumptions work as practical devices that may (...) be useful in cases in which there is insufficient evidence to prove the claim to an appropriate standard of proof. (shrink)

By explaining the argument from ignorance in terms of the presumption of innocence, many textbooks in argumentation theory suggest that some arguments from ignorance might share essential features with some types of presumptive reasoning. The stronger version of this view, suggesting that arguments from ignorance and presumptive reasoning are almost indistinguishable, is occasionally proposed by Douglas Walton. This paper explores the nature and limits of the stronger proposal and argues that initial presumptions and arguments from ignorance are not closely connected. (...) There are three main reasons. First, the argument from ignorance, unlike typical presumptive reasoning, is a negative kind of inference. Second, the typical initial presumption is sensitive to a broader set of defeaters and thus assumes a higher standard of acceptability. Third, in dialectical terms, initial presumption and argument from ignorance bring different attacking rights and obligations. I conclude that Waltonian intuition is unsupported or, at best, is limited only to practical presumptions and practical arguments from ignorance. (shrink)

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.

According to Douglas Walton, the concept of presumption relates to both logical and dialogical components. Logically, a presumption is the conclusion of a presumptive defeasible inference. Dialogically, the function of a presumptions to shift the burden of proof to the respondent in order to move the dialogue forward when the proponent, due to an objective lack of evidence, cannot present a sufficiently persuasive proposition. Presumptive status, assigned only at the argumentation stage of dialogue, is provisional: a particular presumption stands until (...) further counter-indications are found. This paper points out some possible difficulties pertaining to Walton’s dialogical model of presumption. Firstly, once a presumption's typical practical function is made precise, Walton’s idea of presumption starts to lose its conceptual cohesion, thereby becoming applicable in the opening stage of dialogue, as well. Secondly, cohesion is lost also in practical contexts, since Walton's "seat belts" example might indicate that presumptions are not evidentially defeasible if the practical stakes are raised high enough. Most importantly, contextual evaluation may reveal that presumptions do not shift the burden of proof in any specific or genuine way. (shrink)

The aim of this paper is to explore the viability of accounting for presumptions as a subtype of verdictives, within the framework of the Austinian approach to speech acts. The available set of felicity conditions is examined and worked out, in order to try and account in particular for a main feature of presumptions, namely, their function in shifting the burden of proof. In order to extend the Austinian framework as required, the notion of pragmatic presupposition accommodation is shown to (...) be a useful device. (shrink)

Standards and norms for reasoning function, in part, to manage epistemic risk. Properly used, modal qualifiers like presumably have a role in systematically managing epistemic risk by flagging and tracking type-specific epistemic merits and risks of the claims they modify. Yet, argumentation-theoretic accounts of presumption often define it in terms of modalities of other kinds, thereby failing to recognize the unique risk profile of each. This paper offers a stipulative account of presumption, inspired by Ullmann-Margalit, as an inferentially generated modal (...) qualifier, “presumably, p,” distinguishing it from other, particularly epistemic modalities, e.g., standing commitments, assumptions, assertions, suppositions, hypotheses, and defeasible claims. By avoiding the tranching of inferential instruments of qualitatively different bona fides and risk profiles, this account provides a more accurate risk-rating system that better manages epistemic risk in inference, as well as contributing to the normative theory of the operation of presumption in reasoning and argument. (shrink)

In their extensive overview of various concepts of presumption Godden and Walton recognise “the heterogeneous picture of presumptions that exists in argumentation theory today”. I argue that this heterogeneity results from an epiphenomenal character of the notion of presumption. To this end, I first distinguish between three main classes of presumptions. Framework presumptions define the basic conditions of linguistic understanding and meaningful conversation. The “presumption of veracity” is their paradigm case. I argue that such presumptions are satisfactorily covered by the (...) Principle of Charity, or else Gricean maxims or satisfaction conditions for speech acts. Formal presumptions are general presumptive rules of argument, theorised as topoi or acceptable inference warrants, including institutional warrants. Material presumptions are acceptable outcomes of nested or outsourced arguments, which entitles arguers to use them as acceptable premises or opinions in further arguments without the typical burden of proof. If this is correct, then the study of presumption always collapses into the study of other, likely more fundamental, concepts. Does it render presumptions, by Occam’s Razor, altogether redundant in argumentation theory? I tentatively answer this question from a consistently conversational perspective on argumentation; I argue that the pragmatic grounds for presumptions are to be found in the conditions for speech act performance in the institutional social world, as developed by Searle. (shrink)

Although in some contexts the notions of an ordinary argument’s presumption, assumption, and presupposition appear to merge into the one concept of an implicit premise, there are important differences between these three notions. It is argued that assumption and presupposition, but not presumption, are basic logical notions. A presupposition of an argument is best understood as pertaining to a propositional element (a premise or the conclusion) e of the argument, such that the presupposition is a necessary condition for the truth (...) of e or for a term in e to have a referent. In contrast, an assumption of an argument pertains to the argument as a whole in that it is integral to the reasoning or inferential structure of the argument. A logical assumption of an argument is essentially a proposition that must be true in order for the argument aside from that proposition to be fully cogent. Nothing that is both comparable and distinguishing can be said about presumptions of arguments. Rather, presumptions of arguments are distinctively conventional; they are introduced through conventional rules (e.g., those that concern how to treat promises). So not all assumptions and not all presuppositions of arguments are presumptions of those arguments, although all presumptions of arguments are either assumptions or presuppositions of those arguments. This account avoids making the (monological) notion of presumption vacuous and dissolving the distinction between assumption and presumption, which is a vulnerability of alternative views such as Hansen’s and Bermejo-Luque’s, as is shown. (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)

In this paper, I develop a speech-act based account of presumptions. Using a score-keeping model of illocutionary games, I argue that presumptions construed as speech acts can be grouped into three illocutionary act types defined by reference to how they affect the state of a conversation. The paper is organized into two parts. In the first one, I present the score-keeping model of speech act dynamics; in particular, I distinguish between two types of mechanisms—the direct mechanism of illocution and the (...) indirect one of accommodation—that underlie the functioning of illocutionary acts. In the second part, I use the presented model to distinguish between the unilateral act of individual presumption, the point of which is to shift the burden of proof by making the hearer committed to justifying his refusal to endorse the proposition communicated by the speaker, whenever he refuses to endorse it, the bilateral act of joint presumption—‘bilateral’ in that it is performed jointly by at least two conversing agents—the function of which is to confer on the proposition endorsed by the speaker the normative status of jointly recognized though tentative acceptability, and the indirect or back-door act of collective presumption, the purpose of which is to sustain rules and practices to which the conversing agents defer the felicity of their conversational moves. (shrink)

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)

On the standard view, all presumptions share the same deontic function: they asymmetrically allocate the burden of proof. But what, exactly, does this function amount to? Once presumptions are rejected, do they place the burden of arguing, the burden of explanation, or the most general burden of reasoning on their opponents? In this paper, I take into account the differences between cognitive and practical presumptions and argue that the standard accounts of deontic function are at least ambiguous, and likely implausible. (...) As a result, they require qualifications. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

Analogical reasoning is a valuable logical resource in a public health context. It is used extensively by public health scientists in risk assessments of new technologies, environmental hazards and infectious diseases. For its part, the public also avails of analogical reasoning when it assesses a range of public health problems. In this article, some of these uses of analogical reasoning in public health are examined. Analogical arguments have courted approval and disapproval in roughly equal measure by a long succession of (...) logicians and philosophers. The logical features of these arguments which make them simultaneously compelling and contemptible are considered. As a form of presumptive reasoning, analogical arguments have a valuable role to play in closing epistemic gaps in knowledge. This heuristic function of these arguments is illustrated through an examination of some uses of analogical reasoning in recent public health crises. Finally, the results of a study of analogical reasoning in 879 members of the public are reported. This study reveals that lay members of the public are able to discern the logical and epistemic conditions under which analogical arguments are rationally warranted in a public health context. (shrink)

In response to critique by Godden and Walton, this essay delineates the role of moral motivation in the commitment structure of ordinary presumptive inferences. It defends the capacity of ordinary presumptions to support discursive structures within which everyday argumentation can address defeasible claims and enable alignments and realignments in probative obligations, i.e., burdens of proof.

The involvement of social considerations in our ordinary conception of presumption and corresponding plain practice of presuming things raises doubts as to whether they afford epistemically satisfying bases for rational argumentation. To some this involvement illuminates important modes of discursive inquiry; to others it points to the need for theoretically based reform or regulation of our ordinary practices. This paper attempts to clarify and defend the epistemic value of ordinary presumptions.

This paper is an attempt to identify and provide the normative conditions for presumptions and for presumptive inferences. Basically, the idea is adopting the distinction between epistemic and ontological qualifiers proposed in Bermejo-Luque in order to explain the difference between something being a correct presumption and something being presumably the case.

A Bibliography of Douglas Walton’s Published Works, 1971-20.

From 26th to 28th of April 2016, it took place in the University of Granada a conference on presumptions, presumptive inferences and burdens of proof that, joint with other ongoing initiatives, has contributed to renew the interest of the argumentation community in analysing these notions and the relationships between them. This special volume of Argumentation consists of a selection of papers presented at this conference.

This paper outlines an integrated approach to trust and relevance with respect to arguments: in particular, it is suggested that trust in relevance has a central role in argumentation. We first distinguish two types of argumentative relevance: internal relevance, i.e. the extent to which a premise has a bearing on its purported conclusion, and external relevance, i.e. a measure of how much a whole argument is pertinent to the matter under discussion, in the broader dialogical context where it is proposed. (...) Then, we argue that judgements of internal relevance heavily rely on trust, and that such trust, although occasionally misplaced , is nonetheless based on several reasons, and thus often justified, by either epistemic or pragmatic considerations. We conclude by sketching potential methods to formally model trust in argumentative relevance, and briefly discussing the technological implications of this line of research. (shrink)

I argue for the distinction between presuming that p and maintaining that presumably p. In order to make sense of this distinction, I defend a non-inferentialist conception of presumptions and offer an account of the correctness conditions for both presumptions and presumptive inferences. I characterize presumptions as a type of constative speech-act having certain semantic correctness conditions. In turn, regarding presumptive inferences, my strategy is to provide the correctness conditions for the use of an epistemic modal such as “presumably.” This (...) epistemic modal is characterized as a force indicator for speech-acts of concluding in complex speech-acts of arguing involving presumptive inferences. (shrink)

In this paper, I argue that if we have reason to believe that an immaterial soul exists, then it should be presumed to be immortal. The conclusion is weaker than Socrates’ conclusion that immaterial souls must be immortal, but the argument is stronger, I claim, for having this weaker conclusion. Moreover, a presumption of immortality is significant in its own right.

How is the burden of proof to be distributed among individuals who are involved in resolving a particular issue? Under what conditions should the burden of proof be distributed unevenly? We distinguish attitudinal from dialectical burdens and argue that these questions should be answered differently, depending on which is in play. One has an attitudinal burden with respect to some proposition when one is required to possess sufficient evidence for it. One has a dialectical burden with respect to some proposition (...) when one is required to provide supporting arguments for it as part of a deliberative process. We show that the attitudinal burden with respect to certain propositions is unevenly distributed in some deliberative contexts, but in all of these contexts, establishing the degree of support for the proposition is merely a means to some other deliberative end, such as action guidance, or persuasion. By contrast, uneven distributions of the dialectical burden regularly further the aims of deliberation, even in contexts where the quest for truth is the sole deliberative aim, rather than merely a means to some different deliberative end. We argue that our distinction between these two burdens resolves puzzles about unevenness that have been raised in the literature. (shrink)