Ad hominem argument is an argument that attacks the defender of a claim rather than the claim in dispute. The purpose of my dissertation is to answer the question of whether ad hominem argument is fallacious. I search for the answer by exploring several areas of philosophy and discussing ad hominem argument from historical, logical, epistemological, and linguistic perspectives. I reach the following conclusions: First, since the conclusion of an ad hominem argument does not appear explicitly in actual argumentation, how to formulate the conclusion plays a crucial role in judging the legitimacy of ad hominem argument; Second, there is no type of logical fallacy unified under the name of “ad hominem” because, at least, some instances of so-called ad hominem fallacy are epistemically justifiable arguments; Third, since an ad hominem argument is used to refute a person’s testimony by attacking his trustworthiness, an ad hominem argument playing a role of undercutting defeater of a speaker’s testimony is legitimate from the perspective of epistemology of testimony; Fourth, since ad hominem argument can be treated as a speech act of argumentation, an ad hominem argument that satisfies the felicity conditions for argumentation is legitimate from the perspective of speech act theory and an ad hominem argument can be legitimately used to reveal the infelicity of the opponent’s argument. / text

A total of 168 undergraduate students at Temple University provided a measure of their prior beliefs and measures of attitude strength on three topics and then attempted to identify and explain informal reasoning fallacies based on the same topics. Contrary to the hypothesized predictions, prior beliefs and measures of attitude strength did not have a significant effect on participants' ability to accept informal reasoning fallacies consistent with their beliefs based on that topic, although agreement with the topic demonstrated modest effects. Furthermore, this research demonstrated that participants have significant difficulty identifying and explaining informal logical fallacies. Ability to identify and explain one informal fallacy is not a significant predictor of the ability to identify and explain other fallacies. Also, ability to identify and explain one fallacy in a topic is a poor predictor of the ability to identify and explain that fallacy in another topic. This research indicates that formal fallacy syllogism scores were the best predictor of the ability to identify and explain informal logical fallacies, and that agreement with the topic and willingness to act on those beliefs demonstrated modest effects. Consistent with studies on dual-processing theory, in informal logic the individual is forced to examine the information presented in the statement and the structure of the statement and then relate it to their prior opinions and attitudes about the topic, and therefore, the acceptance of the fallacy is a matter of motivated reasoning bias or self-deception instead of an error in analytical reasoning. Informal reasoning fallacies represented an error in judgment, or a misunderstanding of the validity of an argument. Practical implications for school psychologists, limitations of this research, and directions for future research were discussed. / School Psychology

Submitted by Isaac Francisco de Souza Dias (isaac.souzadias@ufpe.br) on 2016-02-29T18:58:53Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Mozart Amorim Sousa.pdf: 1284712 bytes, checksum: 09599b58b5e147f775f8bb0a9b2b8aa1 (MD5) / Made available in DSpace on 2016-02-29T18:58:53Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Mozart Amorim Sousa.pdf: 1284712 bytes, checksum: 09599b58b5e147f775f8bb0a9b2b8aa1 (MD5) Previous issue date: 2015-02-23 / A presente pesquisa teve como objetivo estudar as propriedades psicométricas de um Teste de Raciocínio Lógico-Dedutivo (TRLD). Para tanto, foram realizados dois estudos, sendo o primeiro pela Teoria Clássica dos Testes e o segundo pela Teoria de Resposta ao Item. Ambos contaram com uma amostra de 192 participantes, (65,6% pertencentes ao sexo feminino), todos com idade superior a 18 anos (M=23,9, DP=9,33). Foram aplicados um questionário sociodemográfico, o Teste de Raciocínio Lógico-Dedutivo, a Bateria Fatorial de Personalidade e a Prova de Raciocínio Abstrato da BPR-5. No primeiro estudo, foram investigadas a validade fatorial do TRLD, as precisões dos fatores encontrados e a validade convergente-discriminante, com inteligência fluída (raciocínio abstrato) e traços de personalidade, respectivamente. Uma análise fatorial exploratória revelou uma estrutura com cinco fatores primários e dois fatores de segunda ordem. Os índices de consistência interna foram de 0,844 e 0,708, para os fatores de segunda ordem, respectivamente. Além disso, observou-se correlação moderada e significativa desses fatores com uma medida de raciocínio abstrato (validade convergente) e correlações baixas ou não significativas com traços de personalidade (validade discriminante). O instrumento foi considerado válido e preciso, especialmente para avaliação dos dois fatores de segunda ordem. No segundo estudo os fatores de segunda ordem foram submetidos à Teoria de Reposta ao Item (TRI). Foram analisados o ajuste dos dados ao Modelo de Rasch da TRI (infit e outfit); a adequação do nível de dificuldade dos itens (parâmetro b) ao nível de habilidade dos sujeitos (Ɵ) e a adequação das respostas consideradas corretas. Em ambos os fatores de segunda ordem, os índices de infit e outfit indicaram um bom ajuste dos dados ao Modelo de Rasch e adequação das respostas consideradas corretas, que foram escolhidas pelos participantes com média de theta mais elevada. Além disso, os itens do primeiro fator de segunda ordem apresentaram nível de dificuldade compatível com a média de habilidade dos sujeitos, mas os itens do segundo fator de segunda ordem foram muito fáceis para o nível de habilidade dos sujeitos. Embora algumas melhorias possam ser realizadas em futuros estudos, no geral, pode-se dizer que o instrumento apresentou boas propriedades psicométricas, podendo ser recomendado para uso em pesquisas. / This research aimed to study the psychometric properties of the Logical-Deductive Reasoning Test (LDRT). Therefore, two studies were performed, the first one using the Classical Theory of Tests and the second one, the Item Response Theory. Both relied on a sample of 192 participants (65.6% females), all aged over 18 years old (M = 23.9, SD = 9.33). A sociodemographic questionnaire was applied, as also the Logical-Deductive Reasoning Test, the Personality Factor Battery and the BPR-5 Abstract Reasoning Test. In the first study, there were investigated the LDRT factorial validity, the identified factors' reliabilities and the convergent-discriminant validity, with fluid intelligence (abstract reasoning) and personality traits, respectively. An exploratory factor analysis revealed a structure containing five primary factors and two second-order factors. The results of internal consistency coefficients were 0.844 and 0.708 for the second-order factors, respectively. In addition, it were observed moderate and significant correlations in the measure of abstract reasoning (convergent validity) and low or not-significant correlations in personality traits' results (discriminant validity). The instrument was considered valid and accurate, especially for the two second-order factors evaluation. In the second study, the second-order factors were submitted to the Item Response Theory (IRT). There were analyzed the data adjustment to the IRT Rasch model (infit and outfit); the adequacy between the items' difficulties (parameter b) and the individuals' abilities (.) and the adequacy of the correct answers. In both second-order factors, infit and outfit rates indicated a positive adjustment of the data to the Rasch Model, and the adequacy of the correct answers, chosen by the participants with higher level of theta. Furthermore, the difficulty of the items of the first second-order factor was compatible with the ability average of the participants, however the second factor items were lower than the ability average of the participants. Although some improvements can be implemented in future studies, in general, the instrument demonstrated good psychometric results and, consequently, can be recommended to be used in researches.

With our modern deluge of information through social media, news and blogs, the importance of giving our children a better understanding of source criticism and critical thinking has become increasingly clear. In the field of critical thinking, the use of argument mapping software, a visual way of structuring arguments, has been shown to increase the understanding of arguments, and college students using the method score as much as three times higher on critical thinking tests.  This thesis presents a simplified digital argument mapping tool, developed in order to explore the feasibility of argument mapping for students in secondary school (aged 13-15). The tool is then tested on two secondary school classes. The thesis shows that the students are proficient at basic argument mapping with the tool, but also that the more complex facets of the method require more instruction in order to be used by the students. Recommendations are presented for further development of the argument mapping tool, as well as further studies of critical thinking using argument mapping in secondary school. The thesis has shown the argument mapping has potential for use in secondary school, and should be further studied. / Med vårt moderna överflöd av information genom sociala media, nyheter och bloggar, så ökar vikten av att ge våra unga en bättre förståelse för källkritik och kritiskt tänkande. I fältet kritiskt tänkande har en metod som kallas argument mapping, en visuell metod för att strukturera argument, visats öka förståelsen av argument, samt vid användning studenter i universitet har metoden ökat resultaten på test i kritiskt tänkande upp till tre gånger. Uppsatsen presenterar ett förenklat digitalt argument mapping-verktyg, utvecklat för att studera hur elever på högstadiet (13-15 år) kan använda sig av metoden, som sedan testas på två högstadieklasser. Resultatet visar att studenterna klarar av grundläggande argument mapping med verktyget, men att de mer komplexa delarna av metoden behöver vidare instruktion för att eleverna ska kunna förstå. Rekommendationer presenteras baserat på den data som samlats in, både för vidareutveckling av det designade verktyget, samt för framtida studier av kritiskt tänkande och argument mapping i högstadiet. Uppsatsen visar att argument mapping har potential för användning av högstadieelever, och bör därmed undersökas vidare.

The topic of the present dissertation is argumentation in the late statesman Olof Palme (1927-1986). One may reasonably think that the fascination for Palme is mainly due to his way of expressing his policy, and therefore also to his argumentation strategy. The theoretical background consists of Lloyd F. Bitzers’s theory on the rhetorical situation, Stephen E. Toulmin’s theory on the description of argumentation structures and on the notion of fallacy, as it appears in pragma-dialectics and informal logic. The rhetorical situation is used to identify vital presuppositions and conditions surrounding the analysed argumentation.Toulmin’s theoretical model is used to analyse structures in the argumentation, and the notion of fallacy is used to discover infringements upon these structures. The object of this analysis is the decisive electoral debates of autumn 1976 between Olof Palme and Thorbjörn Fälldin, held in Scandinavium, Gothenburg, Sweden. Palme had to think of a number of surrounding conditions, such as that the debate was decisive, the composition of the audience. Palme and Fälldin otherwise appeared to be rather equally equipped for the debate. Palme’s task was primarily to gain the number of votes needed to continue to keep social democracy in power. There seem to exist several levels making up his argumentation, grouped under attack and defence. Defence is in most cases based upon a strong connection with the social democrat tradition. The attack is more complicated, linked to Palme’s overall argumentative intention: to depict the non-socialists as a bad governing alternative, and the social democrats as a better one. Fallacies are regarded as instances of breaking the frame of rules that govern a critical discussion. Palme has several fallacy-like features in his argumentation. Among those, most common, are that he attacks the person Thorbjörn Fälldin, instead of the policy or party that he represents. Palme also starts from presupposed premises and tries to link the economic policy of the alliance to an intellectually-thought delimiting between liberal and conservative capitalism and social-democrat solidarity. He strives to portray the liberals and conservatives as money-orientated, whereas social democracy is depicted as people-orientated.Palme goes arguably too far at several moments during the debate,which possibly hurts his own argumentation. / Innehåller en 20-sidig utskrift från radions P1 från duellen mellan Palme och Fälldin i Göteborg den 1 sept 1976.