Character Attacks as Complex Strategies of Legal Argumentation

In this paper we analyze leading criminal cases taken from the Supreme Court of the United States, in which ad hominem arguments played a crucial role. We show that although such character attack arguments can be used for legitimate purposes in legal argumentation, in many cases they are weak arguments, but so persuasive that they can effectively prejudice the judgment of a jury. Their dangerous and prejudicial effect can be used as a fundamental component of more complex strategies, aimed, for instance, at shifting the burden of producing evidence or proving character. Using argumentation schemes, we provide criteria for establishing the reasonableness and the weaknesses of this type of argument in different circumstances. We show how ad hominem arguments can be used legitimately as undercutters aimed at undermining the conditions on which arguments from a source (such as arguments from expert testimony) are based. We explain the rhetorical persuasiveness of personal attacks by revealing their structure as complex strategies that fit clusters of arguments together to arouse different types of emotions.