Ad hominem is an informal fallacy whereby an interlocutor, often on the losing side of a debate or argument, resorts to character-based attacks directed at their opponent without any reference to the content or substance of her argument.
Making arguments and convincing others of a proposal is an essential part of human social and political life. Without engaging in arguments and the proposing of solutions, human beings would either be constantly warring with one another (why worry about convincing others when force works just as well) or forced to develop a wide range of skills. Both of these tasks, arguably, are considerably more time consuming than convincing others through well-developed and well-articulated arguments. But arguments are not always perfect, nor are we always in a position to adequately assess them. In such circumstances, arguers and assessors often employ extra-argumentative tactics to appear convincing. One such tactic is the ad hominem attack.
Traditionally, ad hominem attacks or the ad hominem fallacy take two forms: (1) Abusive and (2) Circumstantial (Johnson 2009; Putnam 2010). The circumstantial ad hominem, or tu quoque, is often employed when the principles a person advocates in her argument are inconsistent with her past actions. In colloquial terms, this is the classic “practice what your preach” objection (Johnson 2009; Putnam 2010). Abusive ad hominem attacks, on the other hand, involve a “direct attack on the arguer’s character” (Johnson 2009; Putnam 2010). That is, instead appealing to inconsistency between principles promoted and actions taken, abusive ad hominem attacks are less sophisticated by going after a person’s character traits without appeal to logical or behavioral consistency. For example, someone might charge the arguer with having poor aesthetic taste simply based on their political or otherwise irrelevant character trait.
Are Ad Hominem Attacks Ever Reasonable?
Given the description above, it is difficult to see the argumentative worth of employing any sort of ad hominem attack. To do so, one risks being labeled an unreasonable and irrational interlocutor. Recently, however, much work has been spent challenging the traditional position that ad hominem attacks are irrelevant in evaluating an argument. In Reconsidering the Ad Hominem, Christopher Johnson argues that abusive ad hominem attacks, in certain limited circumstances, can be quite useful and acceptable. There are three such instances. First, and in light of our epistemic and cognitive limitations, ad hominem attacks can be reasonable when we are not positive of the arguers premises. In this instance the evaluator is telling the arguer: “While I am not sure of your premises, you have the reputation of being a swindler and cheat. Thus, one can give very little weight to the belief you are now telling the truth.” The second scenario involves challenging an arguer’s interests or background so as to cast doubt on her ability to assess certainty. Depending on the arguer’s background or motives, their interpretation of facts and her demand for certainty may be said to be too low or too high (2009). Third, and in some ways similar to the second scenario, one might appeal to ideological differences and background for drawing concerns of the arguer’s claims. Here, we might think of the classic scenario where a progressive politician critiques the policy recommendations of a conservative politician based purely on their ideological differences (as opposed to whether the policy recommendations fail to improve lives or solve a developing problem) (Johnson 2009).
Ad Hominem Attacks and Decision-Making
Contrary to traditional economic theory, behavioral economics posits that homo economicus fails both descriptively and pragmatically (Jolls et al. 1998). Setting aside some of the controversial insights of the behavioral economic program, one thing that is of interest to us here is the insight that human beings often employ heuristics when information costs are high. In other words, human beings have what is called bounded rationality. According to Gigerenzer and Gaissmaier (2011), a heuristic is “a strategy that ignores part of the information, with the goal of making decisions more quickly, frugally, and/or accurately than more complex methods.” Arguably, the employment of the ad hominem meets some, if not all, of these elements. In fact, the first scenario described above applies to Jolls et al.’s notion of bounded rationality. Decision-makers such as policymakers are under austere time constraints and may find it difficult to read and digest policy options proposed by their opponents. Thus, it appears reasonable, under the conditions, that they resort to abusive ad hominem attacks quite often.
Given these insights, it might be further argued that employing ad hominem attacks during an argument might contribute to our cognitive efficiency. As rational decision-makers, we are not always equipped with the most up to date and relevant information for all situations where a decision or judgment is required. As such, it is not only more convenient, but also necessary to employ heuristics or cognitive shortcuts that might allow us to make the best decision possible given these cognitive and intellectual restraints. Here, ad hominem attacks can be quite useful. Assessing, let alone winning, an argument does not always come easy. The average arguer will find it difficult to remember or recall all the relevant facts necessary to properly assess or produce an argument. As such, employing ad hominem attacks can be quite useful (Van Eemeren et al. 2000; Yap 2013).
In light of these insights, it would appear that ad hominem attacks are not to be dismissed as intellectually lazy and suspect. To the contrary, they can often prove to be significant resources in light of our cognitive and epistemic limitations. Further, one might also argue that employment of such tactics is not always methodologically or morally dubious. This is not say that there is no instance in which an ad hominem attack can be deemed unreasonable. But it is important for communities to determine under which conditions such attacks are excusable and/or reasonable and when they are merely cheap rhetorical tactics.