Whether abduction is treated as an argument or as an inference, the mainstream view presupposes a tight connection between abduction and inference to the best explanation (IBE). This paper critically evaluates this link and supports a narrower view on abduction. Our main thesis is that merely the hypothesis-generative aspect, but not the evaluative aspect, is properly abductive in the sense introduced by C. S. Peirce. We show why equating abduction with IBE (or understanding them as inseparable parts) unnecessarily complicates argument evaluation by levelling the status of abduction as a third reasoning mode (besides deduction and induction). We also propose a scheme for abductive argument along with critical questions, and suggest retaining abduction alongside IBE as related but distinct categories.

A macroscope is proposed and tested here for the discovery of the unique argumentative footprint that characterizes how a collective (e.g., group, online community) manages differences and pursues disagreement through argument in a polylogue. The macroscope addresses broader analytic problems posed by various conceptualizations of large-scale argument, such as fields, spheres, communities, and institutions. The design incorporates a two-tier methodology for detecting argument patterns of the arguments performed in arguing by an interactive collective that produces views, or topographies, of the ways that issues are generated in the making and defending of standpoints. The design premises for the macroscope build on insights about argument patterns from pragma-dialectical theory by incorporating research and theory on disagreement management and the Argumentum Model of Topics. The design reconceptualizes prototypical and stereotypical argument patterns for characterizing large-scale argumentation. A prototype of the macroscope is tested on data drawn from six threads about oil-drilling and fracking from the subreddit Changemyview. The implementation suggests the efficacy of the macroscope’s design and potential for identifying what communities make controversial and how the disagreement space in a polylogue is managed through stereotypical argument patterns in terms of claims/premises, inferential relations, and presentational devices.

Negotiation is not only used to settle differences of interest but also to settle differences of opinion. Discussants who are unable to resolve their difference about the objective worth of a policy or action proposal may be willing to abandon their attempts to convince the other and search instead for a compromise that would, for each of them, though only a second choice yet be preferable to a lasting conflict. Our questions are: First, when is it sensible to enter into negotiations and when would this be unwarranted or even fallacious? Second, what is the nature of a compromise? What does it mean to settle instead of resolve a difference of opinion, and what might be the dialectical consequences of mistaking a compromise for a substantial resolution? Our main aim is to contribute to the theory of argumentation within the context of negotiation and compromise formation and to show how arguing disputants can shift to negotiation in a dialectically virtuous way.

Contemporary reasoning about health is infused with the work products of experts, and expert reasoning about health itself is an active site for invention and design. Building on Toulmin’s largely undeveloped ideas on field-dependence, we argue that expert fields can develop new inference rules that, together with the backing they require, become accepted ways of drawing and defending conclusions. The new inference rules themselves function as warrants, and we introduce the term “warranting device” to refer to an assembly of the rule plus whatever material, procedural, and institutional resources are required to assure its dependability. We present a case study on the Cochrane Review, a new method for synthesizing evidence across large numbers of scientific studies. After reviewing the evolution and current structure of the device, we discuss the distinctive kinds of critical questions that may be raised around Cochrane Reviews, both within the expert field and beyond. Although Toulmin’s theory of field-dependence is often criticized for its relativism, we find that, as a matter of practical fact, field-specific warrants do not enjoy immunity from external critique. On the contrary, they can be opened to evaluation and critique from any interested perspective.

This paper discusses idiomatic expressions like ‘that says it all’, ‘that says a lot’ etc. when used in presenting an argument. These expressions are instantiations of the grammatical pattern that says Q, in which Q is an indefinite quantifying expression. By making use of the pragma-dialectical theory of argumentation and the linguistic theory of construction grammar it is argued that instantiations of that says Q expressing positive polarity (‘it all’, ‘everything’, ‘much’, ‘a lot’, ‘something’) can fulfil the role of an argumentation’s (explicitly expressed) linking premise. Furthermore, an analysis of these expressions as presentational devices shows that an arguer can use them for strategic reasons, i.e. to leave the exact formulation of the standpoint implicit and to present the argument as self-evident. Using these devices derails into fallaciousness when the context offers insufficient clues to reconstruct the standpoint or when the argument does not offer the kind of support that would be required by the specific instantiation of Q. The argumentative function of instantiations of that says Q expressing negative polarity (‘little’, ‘nothing’ and other denials of those expressing positive polarity) is that an antagonist can use them to attack the justificatory power of the protagonist’s argument.

Can argumentation schemes play a part in the critical processing of argumentation by lay people? In a qualitative study, participants were invited to come up with strong and weak arguments for a given claim and were subsequently interviewed for why they thought the strong argument was stronger than the weak one. Next, they were presented with a list of arguments and asked to rank these arguments from strongest to weakest, upon which they were asked to motivate their judgments in an interview. In order to assess whether lay people apply argument scheme specific criteria when performing these tasks, five different argumentation schemes were included in this study: argumentation from authority, from example, from analogy, from cause to effect, and from consequences. Laypeople’s use of criteria for argument quality was inferred from interview protocols. The results revealed that participants combined general criteria from informal logic (such as relevance and acceptability) and scheme-specific criteria (such as expertise for argumentation from authority, similarity for argumentation from analogy, effectiveness for argumentation from consequences). The results supported the conventional validity of the pragma-dialectical argument scheme rule in a strong sense and provided a more fine-grained view of central processing in the Elaboration Likelihood Model.

Dialogical egalitarianism is the thesis that any proposition asserted in dialogue, if questioned, must be supported or else retracted. Dialogical foundationalism is the thesis that some propositions are privileged over this burden of proof, standing in no need of support unless and until support for their negation is provided. I first discuss existing arguments for either thesis, dismissing each one of them. Absent a successful principled argument, I then examine which thesis it is pragmatically more advantageous to adopt in analytic philosophical dialogue. This requires identifying the goal of such dialogue, to the attainment of which the thesis would be so advantageous. To identify this goal, I draw on Douglas Walton’s typology of dialogues for an analysis of the types of dialogue of 110 representatively selected journal articles in current analytic philosophy. 95% of articles are found to instantiate persuasion dialogue. In light of the thus prevalent goal of persuading one’s opponent, I argue that the adoption of dialogical egalitarianism in analytic philosophical dialogue is pragmatically inescapable.