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.

In this paper a dialogue game for critical discussion is developed. The dialogue game is a formalisation of the ideal discussion model that is central to the pragma-dialectical theory of argumentation. The formalisation is intended as a preparatory step to facilitate the development of computational tools to support the pragma-dialectical study of argumentation. An important dimension of the pragma-dialectical discussion model is the role played by speech acts. The central issue addressed in this paper is how the speech act perspective can be accommodated in the formalisation as a dialogue game. The starting point is an existing ‘basic’ dialogue game for critical discussion, in which speech acts are not addressed. The speech act perspective is introduced into the dialogue game by changing the rules that govern the moves that can be made and the commitments that these result in, while the rules for the beginning, for the end, and for the structure of the dialogue game remain unchanged. The revision of the move rules is based on the distribution of speech acts in the pragma-dialectical discussion model. The revision of the commitment rules is based on the felicity conditions that are associated with those speech acts.

This paper makes an independent start with formalizing the rules for the argumentation stage of critical discussions (van Eemeren and Grootendorst A systematic theory of argumentation: The pragma-dialectical approach, Cambridge University Press, Cambridge, 2004, Ch. 6). It does not deal with the well-known code of conduct consisting of ten rules (the “ten commandments”) but with the system consisting of fifteen (or seventeen) rules on which the code of conduct is based. The rules of this system are scrutinized and problems they raise are discussed. Then a formal dialectical system is defined that reflects most of the contents of these rules. The aim is to elucidate the way the rules work and to show how a formal approach can be useful to achieve this. It is also shown how the present method can be used to study the nature of circular argumentation. While, generally, the formalization follows closely the original rules for the argumentation stage of critical discussions, there will also be proposed some modifications of the original protocol.