Critical thinking on a logical fallacy
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.