Everyday life reasoning and argumentation is defeasible and uncertain. I present a probability logic framework to rationally reconstruct everyday life reasoning and argumentation. Coherence in the sense of de Finetti is used as the basic rationality norm. I discuss two basic classes of approaches to construct measures of argument strength. The first class imposes a probabilistic relation between the premises and the conclusion. The second class imposes a deductive relation. I argue for the second class, as the first class is (...) problematic if the arguments involve conditionals. I present a measure of argument strength that allows for dealing explicitly with uncertain conditionals in the premise set. (shrink)

This thesis justifies the need for and develops a new integrated model of practical reasoning and argumentation. After framing the work in terms of what is reasonable rather than what is rational (chapter 1), I apply the model for practical argumentation analysis and evaluation provided by Fairclough and Fairclough (2012) to a paradigm case of unreasonable individual practical argumentation provided by mass murderer Anders Behring Breivik (chapter 2). The application shows that by following the model, Breivik is relatively easily able (...) to conclude that his reasoning to mass murder is reasonable – which is understood to be an unacceptable result. Causes for the model to allow such a conclusion are identified as conceptual confusions ingrained in the model, a tension in how values function within the model, and a lack of creativity from Breivik. Distinguishing between dialectical and dialogical, reasoning and argumentation, for individual and multiple participants, chapter 3 addresses these conceptual confusions and helps lay the foundation for the design of a new integrated model for practical reasoning and argumentation (chapter 4). After laying out the theoretical aspects of the new model, it is then used to re-test Breivik’s reasoning in light of a developed discussion regarding the motivation for the new place and role of moral considerations (chapter 5). The application of the new model shows ways that Breivik could have been able to conclude that his practical argumentation was unreasonable and is thus argued to have improved upon the Fairclough and Fairclough model. It is acknowledged, however, that since the model cannot guarantee a reasonable conclusion, improving the critical creative capacity of the individual using it is also of paramount importance (chapter 6). The thesis concludes by discussing the contemporary importance of improving practical reasoning and by pointing to areas for further research (chapter 7). (shrink)

The African philosophy of Ubuntu is typically characterised as a communitarian philosophy that emphasises virtues such as compassion, tolerance and harmony. In recent years there has been growing interest in this philosophy, and in how it can be applied to a variety of disciplines and issues. Several authors have provided useful introductions of Ubuntu in the field of business ethics and suggested theoretical ways in which it could be applied. The purpose of this paper is to extend this discussion by (...) providing a more critical analysis of Ubuntu and business ethics with the aim of clarifying the role that Ubuntu can play, and providing guidance for further research in this area. The analysis consists of three sections. In the first, certain problems are identified within the existing literature. This is followed by a consideration of alternative perspectives and interpretations of Ubuntu. The last section, following from the first two, identifies specific areas requiring further research, both empirical and non-empirical, as well as ways in which Ubuntu could be fruitfully applied. (shrink)

This study analyzed the argumentative writing behavior of Iranian graduate learners of English as Foreign Language in their English essays. Further, the correlations between the use of argument elements and overall writing quality as well as soundness of produced arguments were investigated. To this end, 150 essays were analyzed. The sample essays were found to be predominantly deductive in terms of rhetorical pattern. Moreover, they mainly utilized ‘data’ and ‘claim’ most frequently with secondary elements of argument as the least produced (...) elements. Overall writing quality co-varied significantly positively with the uses of claims, data, counterargument claims, counterargument data, rebuttal claims, and rebuttal data. Essays rated high in terms of overall writing quality were further rated for soundness and relevance of the arguments. The results demonstrate that even for advanced language learners good surface structure cannot necessarily guarantee well thought-out logical structure. The pedagogical implications for writing instruction and research are discussed. (shrink)

This article identifies the moral premises of contemporary business ethics. After analyzing thirty business ethics texts, the article shows that many business ethicists hold the conventional view that being moral is altruistic. This altruistic perspective logically implies a negative evaluation of self-interest and the profit motive, and business. As a result, the prevailing attitude in mainstream business ethics is that without altruistic restraints businesspeople are inclined to lie, steal, and cheat, not create and earn wealth through honest production and voluntary (...) trade. Therefore, the central concern in current business ethics is to curb businesspeople morally, not to empower them in their self-interested desire to make money. In the final analysis, the article shows how the anti-egoist assumptions manifest themselves in a moral prejudice against business, leading to a biased, unfair, and misleading account of the business world. (shrink)

ABSTRACTThis paper studies abduction in abstract argumentation frameworks. Given an argument, an agent verifies whether the argument is justified or not in its argumentation framework. If the argument is not justified in the argumentation framework, the agent seeks conditions to explain the justification state by hypothesising arguments in the universal argumentation framework. We formulate such abductive reasoning in argumentation semantics and provide its computation in logic programming. We also apply abduction to enforcement and simple dialogue games in argumentation frameworks.

There is no concept more central to logic and critical thinking than the concept of an argument. I here address the definition of ‘argument’ in the logical sense of the term and defend the claim that many current proposals, once they are interpreted in a way that makes them sufficiently precise, are extensionally inadequate. Definitions found in some contemporary, prominent critical thinking textbooks will serve as a springboard. I claim that each may be interpreted in an absolutist way or a (...) relativistic way, yet all turn out to be objectionable no matter which route is taken. I finish with a proposal on which the definition of ‘argument’ is an absolutist one, yet one that avoids the problems discussed for the earlier proposals. (shrink)

Much of what we believe we know, we know through the testimony of others. While there has been long-standing evidence that people are sensitive to the characteristics of the sources of testimony, for example in the context of persuasion, researchers have only recently begun to explore the wider implications of source reliability considerations for the nature of our beliefs. Likewise, much remains to be established concerning what factors influence source reliability. In this paper, we examine, both theoretically and empirically, the (...) implications of using message content as a cue to source reliability. We present a set of experiments examining the relationship between source information and message content in people's responses to simple communications. The results show that people spontaneously revise their beliefs in the reliability of the source on the basis of the expectedness of a source's claim and, conversely, adjust message impact by perceived reliability; hence source reliability and message content have a bi-directional relationship. The implications are discussed for a variety of psychological, philosophical and political issues such as belief polarization and dual-route models of persuasion. (shrink)