ISSA Proceedings 2002 – Logical Dialectics: The Missing Link Between Deductivism And Pragma-Dialectics

• by: Henry Prakken - Institute of Information and Computing Sciences, Utrecht University

1. Introduction
For a long time, the fields of formal logic and argumentation theory seemed to ignore each other. However, in more recent years the two communities seem to grow towards each other again. One reason for this is the interest in Artificial Intelligence in the logic of common sense reasoning and everyday argumentation. Partly drawing on insights from argumentation theory, AI has provided formal and computational studies of phenomena that for decades were regarded as the province of informal logic and argumentation theory. Two years ago, the two communities met physically, at the very successful Symposium on Argument and Computation in Pitlochry, Scotland, organised by Tim Norman and Chris Reed. A consensus seems growing that both communities can learn a lot from each other.
The aim of this paper is to illustrate this point with an analysis of one issue with respect to which argumentation theory has long criticised formal logic, viz. the issue whether deductive validity is the only criterion for evaluating arguments. Argumentation theorists such as Perelman have persuasively argued that that there is more to reasoning than the deductive form of mathematical arguments. Perelman (e.g. Perelman & Olbrechts-Tyteca 1969) stressed that everyday arguments are not simply valid or invalid, but more or less strong, relevant or persuasive. Moreover, Perelman challenged logicians to supplement standard logic with a theory of argumentation that can account for this phenomenon. In this paper, I argue that such an account has become possible by combining various research developments from the last two decades, viz. formal dialogue systems from argumentation theory, models of legal procedure from AI & Law, and models of defeasible reasoning from AI.
I will develop my argument as a critical response to a very interesting recent paper by Leo Groarke in defence of so-called ‘deductivism’ (Groarke 1999). In Section 2 of this paper I will briefly outline and illustrate Groarke’s deductivist account of everyday-argument validity. In Section 3 I shall argue that this account, although definitely illuminating, still ignores some essential elements of everyday arguments. In Section 4 I shall put my analysis in a wider perspective, discussing the relevance of research on argumentation schemes. Read more

ISSA Proceedings 2002 – Arguing National Missile Defense: Evaluating The Bush Administration’s “New Framework” For Nuclear Security

• by: Theodore O. Prosise - Department of Communication, University of Washington

Abstract
Addressing the National Defense University on May 1 of this year, President George W. Bush outlined a “new framework” for nuclear security in the post-Cold War world.  This new framework is based on two key policy moves. First, the United States will develop and deploy a robust National Missile Defense (NMD). Second, it will reduce its nuclear arsenal to a minimal “credible” level.  In light of the dangers that nuclear weapons pose and given the historic difficulties in sustaining support for missile defense this essay examines the Bush Administration’s arguments for NMD.  Following the direction Edward Schiappa provides in Warranting Assent, this essay evaluates the Bush Administration’s justification for NMD. The essay considers what the NMD arguments accomplish for the administration. This essay maintains that the Bush Administration is arguing for NMD because it is a necessary component of an overall policy of extending nuclearism from the Cold War to the post-Cold War world.

The Bulletin of Atomic Scientists Board of Directors in March/April of 2002 moved the “Doomsday Clock” from nine to seven minutes to midnight. Despite the initial promise of reducing the nuclear threat after the close of the superpower conflict, this is the third time the clock’s hands have been moved closer to midnight in the post-Cold War era (Bulletin 2002). The specter of nuclear terrorism is growing and India and Pakistan stand perilously close to a nuclear conflict, which should remind us of Robert Manning’s warning several years ago that “the likelihood of nuclear use – either in a regional conflict or by terrorists – is probably greater now than in the bipolar superpower era” (1997-1998: 70-71). Even as threats grow, we have yet to see substantial qualitative movement away from nuclearism. Both the Bush Sr. and the Clinton administrations were progressing on a trajectory of reducing the number of nuclear weapons through verified and binding arms control agreement. But struck by the perceived lack of progress, credentialed anti-nuclear voices since the mid-1990s have sought to bring the debate over nuclear policy from the technical to the public sphere, encouraging public moral argument about U.S. nuclear weapons policy and explicitly advocating a massive and fundamental change in U.S. nuclear policy.  These nuclear “abolitionists” have challenged the nuclear establishment’s exclusive purview over public policy argument, criticized current force structure policy, and the very necessity of nuclear weapons in the post-Cold War world (Prosise 2000).
Partly in response to such criticism, the Bush administration has recently reframed the public debate over nuclear weapons, claiming to offer an alternative to Cold War nuclearism, and, implicitly, nuclear abolition as well (“President Bush’s” 2001)(i).  This “new framework” is explicitly intended to reduce the dangers of nuclear weapons and enhance the security of the United States and its allies by maintaining maximum nuclear flexibility and by shielding vital interests from ballistic missile attacks. While Bush is offering an alternative to Cold War nuclearism, it has not “clashed” with these abolitionists’ arguments directly. Indeed, the Bush administration has barely acknowledged the abolitionists, but they were in the minds of those who crafted the new post-Cold War nuclear posture, informed Bush’s new framework, and set the ground for the recent May arms control accord with Russia (“Rationale” 2001; see also, Doa 2002; Gordon May 9, 2001). Read more

ISSA Proceedings 2002 – Strength And Order In Practical Reasoning: Decision-Guiding Argumentation

• by: Luis A. Pérez-Miranda - ILCLI-The University of the Basque Country (UPV/EHU)

Abstract
Beliefs are the only evidence available for an agent making decisions about whether what he wants to do is justified under the circumstances or not. We think the connection between beliefs and goals can be evaluated according to order and strength criteria. Order among supporting reasons constrains the decision-guiding argumentation process to only those decisions that are relevant for the agent while just excluding or postponing the others. Strength determines the expected degree of utility derived from the adoption or non-adoption of a goal. An agent would only be justified in adopting a goal when the reason that supports it remains undefeated.

Introduction
Practical reasoning seems to help the agent in the way of constructing strategies and plans in his pursuit of a better situation for himself. The goals and objectives of an agent can be of diverse nature, from mere intrinsic desires to sub-goals of already intended plans. For instance, to be thirsty is usually a reason for adopting the goal of finding water or some other refreshment to quench one’s thirst. Similarly, the obligation of starting work at nine o’clock every morning can be a sufficient reason for adopting the goal of getting up at half past seven daily. Other goals just respond to exigencies arising from intended plans (e.g. getting a ticket for the Symphony Hall can be just a sub-goal of my intended plan for the weekend). One of the tasks of practical reasoning is to cope with conflict situations of decision-making among an agent’s potential goals. To be sure, sometimes an agent is forced to choose among different relevant options that are jointly incompatible.
Our approach assumes that, though not always, in many cases, the adoption of goals is plan dependent. Generally it happens that a goal cannot be adopted before the agent realizes that he is able to bring a plan about for the occasion. Often an important amount of the value of a goal is directly obtained from the expected utility value of the plan in which it is embedded (Beaudoin 1994). In more detail, the adoption of a goal would be related to three factors: the value of the goal itself, the possibility of constructing a plan pursuing a previously learnt strategy for that goal, and the agent’s commitments to previous plans (Pérez Miranda 1997). Hence to justify the adoption of a goal the rational agent must be able to construct a solid decision-guiding argument. That is, the practical argument constructed for the occasion should remain undefeated after the reasoning process. ‘Practical reasoning is based on an agent’s goals relative to a situation and on his knowledge of what is usually (reasonably expected) to obtain, according to his knowledge of the situation. …Typically, this pragmatic type of reasoning is based on rules or regularities that admit exceptions. Hence the conclusion is based on a kind of plausible reasoning – it represents a type of provisional presumption that could be subject to rejection or revision in the face of the new evidence, or of new developments in the situation’ (Walton 1990: 84).
Once the agent has recognized that a potential goal is obtainable, the next step in determining the adoption of a goal is to detect any incompatibilities between that goal and other possible intended goals derived from previous intended plans or single urgencies that ought to be accomplished without delay. Hence the agent must look for scenarios in which both potential goals and ongoing adopted goals fit together insofar as fulfilling one may be at odds with fulfilling another or with maximum fulfilment of the overall set. We are concerned with explaining how an agent could manage to make these factors fit together appropriately by adopting a behaviour consisting in, so to speak, following some rational patterns.
The evaluative mechanism proposed here is only concerned with those goals that have a motivational or cognitive grounding (see below). According to our model, the rational agent selects only those goals whose supporting reasons are undefeated according to the agent’s doxastic states. The mechanism embodies two levels of decision-making depending on the order and strength of the supporting reasons. An agent only would be justified in adopting a goal when the reason that supports that goal remains undefeated. Read more

ISSA Proceedings 2002 – A Collaborative Model Of Argumentation In Dyadic Problem-Solving Interactions

• by: Matthieu Quignard - UMR 5612 GRIC, CNRS & Université Lumière Lyon 2

1. Introduction
Within a cognitive approach to argumentation, our research deals with the argumentative processes of knowledge co-construction in dialogue (Baker, 1999). From this point of view we have been designing experimental situations favouring argumentation in dyadic problem-solving (Quignard & Baker, 1998; Baker, Quignard, Lund & van Amelsvoort, this volume) over several years, in order to understand the roles of argumentation in the resolution of conceptual problems (Baker, 1998; Baker, Brixhe & Quignard, 2002). Whereas our previous research focussed on socio-cognitive conditions promoting emergence of argumentation between learners (Quignard, 1999 from a previous work of Golder, 1996), in this paper we address the problem of analysing the argumentation processes carried out in problem-solving dialogues and the interactional phenomena by which knowledge is collaboratively elaborated. On one hand, our cognitive approach to argumentation is naturally very closely related to pragmatics studies of dialogue, which aim to describe or analyse the relationships between the use of language and its social or contextual implications in concrete situations. On the other hand, the phenomenon we want to explain – argumentation – has been very well described in normative models of dialectics, which give quite solid bases for defining the limits of argumentation phases, their genuine moves and schemes (attacks and defences) and their rules. The proof of the consistency of such dialectical systems (see fore example Barth & Krabbe, 1982) is another argument in favour of their universal domain of application. These two very different approaches to argumentation are not necessarily to be opposed when the pragmatic foundations of the logic of these systems can be defined with some degree of formality (see for example Quignard & Baker, 1997). Recent developments in pragma-dialectics (van Eemeren & Grootendorst, 1992) have shown the efficiency of this combination, being both a normative and descriptive method for understanding argumentative discourse (van Eemeren et al., 1993) or designing argumentation situations, even for the purposes of learning (see Jackson, 1998).

In fact, – and without playing on words – the previous models of argumentation meet their limits when dialogue is not yet or no longer argumentative. In other terms, when argumentation is too much considered as a verbal activity per se (with its own rules and own moves) there are some difficulties in taking into account cognitive continuum underlying the dialogue, for example rational commitments or problem-solving goals. Krabbe (1988) in an answer to Lorenz (Ibid.) stated that argumentative commitments can obtain in non-argumentative phases (e.g. theses), and thus some argumentative rules could prevail outside argumentative phases. In a later paper with Walton (1995), he tried to provide a logical framework for keeping trace of commitments across different dialogue phases, but that approach cannot be considered as a cognitive model. Another difficulty concerns the definition of a set of argumentative moves for the sake of describing argumentation processes. These moves cannot relate to the general process of dialogue, since they concentrate on purely argumentative objects of discourse: theses and arguments. Therefore, argumentation is disconnected from the pragmatic context of the dialogue from which it emerged, like a dialectical game interrupting a collaborative action. In fact, collaborative action (or the general goal of the dialogue) underlies the argumentation, and may change at any time (for example a conflict dissolution because they need to carry on to another topic). Nevertheless, it is clear that providing two separate sets of speech acts for analysing both parallel processes independently (argumentation and general dialogue) is not a satisfactory solution either since at least for cognitive reasons, these processes are very much linked with each other.

Therefore, a solution would be to derive argumentation moves from general dialogue categories, allowing a unique cognitive action to achieve several functions at a time. The multi-functionality of utterances has been already used in many cases to explain the quantity of things one can do with so few words. Authors like Allwood (1995) or Bunt (1994) have used it to distinguish task-oriented speech acts to dialogue control ones (for interaction management). Our main idea is based on the very pragmatic conception of dialogue from Morris or Clark, who considered dialogue as a verbal problem-solving activity (people use language for collaborating with respect to a given problem). The key point for our concern is to consider argumentation as a specific case of problem-solving, where the problem is the “conflict of avowed opinions” (Barth & Krabbe, op. cit.). Read more

ISSA Proceedings 2002 – The Limits Of Intuitive Argumentation: Thomas Aquinas On The Communication Between Separated Substances

• by: Mart Raukas

1. Preliminary remarks
In this paper I make an attempt to analyze Aquinas’ doctrine of the an­gels’ speech (communication between separated substances), both as such and with regard to understanding the limits of intuitive argumentation(i).
It is well known that Thomas was always very clear to distinguish philosophical arguments from theological arguments. However, in the modern reception of Aquinas philosophical arguments, there are prob­lems of interpretation in which we need:
a. to specify their factual or historico-theological background. We would label such problems roughly as historico-factual problems.
b. to reflect logically on what is already factually and contextually known. Many modern commentators of Aquinas have demonstrated that sometimes behind the commonly under­stood passage the deeper conceptual scheme reveals itself only if our in­terpretation is assisted by some kind of ‘mental scalpel’  – scrupulous logical analysis or some other technique of contemporary analytical philosophy. I would label such problems as logico-conceptual ones.

In what follows, I intend to restrict myself to the last sort of prob­lems. This is neither a paper about angelology nor about the history of medieval ideas. My approach will not be apologetic. That is, I will nei­ther try to prove the rightfulness of Aquinas’ arguments nor to refute them. Instead of asking Aquinas’ question: ‘Whether one angel speaks to another?’, I will ask: How would be the conception of angels’ speech, de­scribed by Thomas in the Summa Theologiae la. 107, 1-5 compre­hended in the light of contemporary analytical mind?
The way medieval philosophy approached divine things are, no doubt quite different from what the analytical philosophers are approach­ing today. First, then there is distinction of human knowledge in respect to its possible origins between lumine divinae revelationis and lumine naturalis rationis. It is the epoch-making distinction which covers all the ‘conceptual architectonic’ of the Summa Theologiae, and which, with some qualification can be found in medieval philosophy in general. This is the distinction what states: There are truths that transcend our natural reason but do not contradict it; these truths are the truths of revelation, obtained by saints through the grace of God; evident to angels, and in some way to saints, but not understandable to us. Read more

ISSA Proceedings 2002 – A Non-Propositional Approach To Emotions In Argument

• by: Pedro Reygadas - Universidad de la Ciudad de México

In this paper we try to show why it is inadequate to approach emotions within a pragma-dialectic or propositional approach to argument. We confine ourselves to the arguments related to language and discourse. We do not claim that pragma-dialecticians must disappear, what we claim is that the constant movement they try to make in favor of an expansion of their approach is illegitimate. Pragma-dialectics is only a theory of written and highly critical discourse, of computational logical analysis.
Van Eemeren and Houtlosser accept the importance of three levels of rhetorical strategies:
1. the selection of the material,
2. its adaptation to the audience and
3. its presentation.
But the way they analyze them is valid only in their framework. Their claim that we need to start “from the assumption that rhetoric may be considered to operate within a dialectical framework” (van Eemeren and Houtlosser 2000, 2) is not valid beyond the critical, propositional and artificial intelligence approach to argument.
I propose five interrelated lines of thought: the three cited by van Eemeren and Houtlosser and two more:
4. the presence of emotions in speech acts as a nuclear component furnishing motives for action; and
5. the necessity of studying emotions as enculturated phenomena. The difference is that for me the selection operation with which any argumentative discourse begins (the old inventio) is necessarily a relative cultural phenomenon. The relevance of the disposition of the arguments challenges the propositional approach. And the presentation of arguments shows us the inevitability of emotions in language. We cannot consider emotions as a minor component or as a mere accompaniment of the logical-dialectical component. Reason is not divisible; it encompasses the whole of logic, emotion, belief, value and intuition.

1. Emotions and the selection operation
Van Eemeren and Grootendorst (van Eemeren and Grootendorst, 1996) consider the topoï in their logical sense. They perceive that two operations occur in regard to topoï: the selection operation and the warrant operation. They do not care about selection and focus on the warrant role.
Van Eemeren and Houtlosser change the original pragma-dialectical view. They consider the inventio in order to achieve the optimal rhetorical result. The selected moves must be an effective choice made from the available potential moves. The moves must be in such a way adapted to the audience that they comply with auditorial demands.
We cannot discuss this option in the pragma-dialectician terms. What we want to argue is that if there is a warrant function of topoï it is because there was before or at the same time a selection operation. And this selection is rhetorical and is crucial to the argument in a sense that goes beyond the pragma-dialectical interest. If the selection is not well done, then the very possibility of convincing is ruled out, and we will not be able to work on the discourse. This selection still has a logic component but is deeply rooted in intuition and emotion, in what we feel is right and adequate. The conjecture of the neuro-physiologist Antonio Damasio (Damasio, 1994) is that making a decision is an activity guided emotionally by “somatic markers” that filter decisions. And, moreover, decisions are also a cultural and ideological election. And the emotional appeal of a selection can have dramatic consequences even in the most critical discourse, which is scientific discourse. Read more