Issues in conductive argument weight

The concept of conductive argument weight was developed by Carl Wellman and later by Trudy Govier. This concept has received renewed attention recently from another informal logician, Robert C. Pinto. Argument weight has also been addressed in recent years by theorists in AI & Law. I argue from a non-technical perspective that some aspects of AI & Law’s approach to argument weight can be usefully applied to the issues addressed by Pinto. I also relate some of these issues to the work of argument theorist Harald Wohlrapp

Fully Convective Magnetorotational Turbulence in Stratified Shearing Boxes

We present a numerical study of turbulence and dynamo action in stratified shearing boxes with zero magnetic flux. We assume that the fluid obeys the perfect gas law and has finite (constant) thermal diffusivity. We choose radiative boundary conditions at the vertical boundaries in which the heat flux is propor- tional to the fourth power of the temperature. We compare the results with the corresponding cases in which fixed temperature boundary conditions are applied. The most notable result is that the formation of a fully convective state in which the density is nearly constant as a function of height and the heat is transported to the upper and lower boundaries by overturning motions is robust and persists even in cases with radiative boundary conditions. Interestingly, in the convective regime, although the diffusive transport is negligible the mean stratification does not relax to an adiabatic state.Comment: 11 pages, 4 figures, accepted for publication in ApJ Letter

A critical examination and development of Wellman’s theory of conductive argument

The paper aims to provide an analysis and critique of Carl Wellman’s account of conduction presented in Challenge and Response and Morals and Ethics. It considers several issues, including: reason-ing vs. argument, the definition vs. the three patterns of conduction, pro and con arguments as dialogues, their assessment, the concept of validity, applications beyond moral arguments, argument type vs. as crite-rion of evaluation

The Notion of On-balance Premise Reconsidered

The notion of on-balance premise has played a crucial role in understanding the structure of conduction. It is a widely accepted view that in any third-pattern conductive argument there is always an implicit on-balance premise which represents a judgment that the positive reasons for the conclusion have outweighed the counter-considerations against it. This paper aims to provide a critical examination of the notion, and to reveal its inadequacy as a theoretical tool. First, it argues that the notion of on-balance premise has rested upon a metaphor of outweighing that is too simplistic to characterize the weighing and balancing between reasons and counter-considerations. Second, it discusses the justification of on-balance premise in third-pattern conductive arguments, and argues that the current efforts made to validate the on-balance premise as a missing premise remain to be unsuccessful

Apparatus to probe the influence on the Casimir effect of the Mott-Anderson metal-insulator transition in doped semiconductors

We describe an isoelectronic differential apparatus designed to observe the influence on the Casimir force of the Mott-Anderson metal-insulator transition in doped semiconductors. Alternative theories of dispersion forces lead to different predictions for this effect. The investigation of this problem by standard apparatus, based on absolute measurements of the Casimir force, is very difficult because the effect is small in the region of sub-micron separations, where the Casimir force can be measured precisely. The differential apparatus described here is immune by design to several sources of error that blur the interpretation of Casimir experiments, like electrostatic patches, inaccurate determination of plates separation, surface roughness and errors in the optical data. With the help of the proposed setup it should be possible to establish conclusively which among the alternative theories of the Casimir effect for semiconducting test bodies is correct.Comment: 14 pages, 9 figures, accepted for publication in Phys. Rev.

Conductive arguments and the ‘inference to the best explanation’

I will demonstrate that conductive arguments are found in the inference to the best explana-tion as it is used in science. Conductive arguments, I argue, operate on two levels: the first is in the con-struction of hypotheses; the second is through the competition of hypotheses. By constructing arguments based on observations of facts, all possible (conceivable) factors are taken into account and a judgment is made based on our weighing of considerations: conductive argumentation

Reason in the balance: Teaching critical thinking as dialectical

In this paper we describe the approach to critical thinking pedagogy used in our new text, Reason in the Balance: An Inquiry Approach to Critical Thinking. In this text we concentrate on develop-ing students’ ability to analyze and assess competing arguments in a dialectical context. This approach shifts the emphasis from the more common and traditional approach of evaluating individual arguments and fallacy identification. Our focus is on teaching students to analyze and assess competing arguments sur-rounding an issue with the goal of achieving a reasoned and justifiable judgment (an enterprise we refer to as inquiry)

Formalizing Informal Logic

In this paper we investigate the extent to which formal argumentation models can handle ten basic characteristics of informal logic identified in the informal logic literature. By showing how almost all of these characteristics can be successfully modelled formally, we claim that good progress can be made toward the project of formalizing informal logic. Of the formal argumentation models available, we chose the Carneades Argumentation System (CAS), a formal, computational model of argument that uses argument graphs as its basis, structures of a kind very familiar to practitioners of informal logic through their use of argument diagrams