Argumentum ad hominem are arguments against the person. Arguments ad hominem are, as Copi & Cohen (1990) wrote: “a fallacious attack in which the thrust is directed, not at a conclusion, but at the person who asserts or defends it.” There are two main types of ad hominem attacks: the general abusive form and the circumstantial form (which may be seen as a subset of the abusive form).
The general form takes this process (Bennett, 2013):
“Person 1 is claiming Y.
Person 1 is a moron.
Therefore, Y is not true.” (Emphasis in original.)
For example from Lunsford & Ruszkiewicz (1999): “Critics of Rush Limbaugh’s conservative stances rarely fail to note the radio commentators’ weight.”
Ad hominem attacks are generally used to defame the character, deny the intelligence, question the trustworthiness, or otherwise to belittle an opponent in an argument. However, as Copi & Cohen (1990) point out, “The character of an individual is logically irrelevant to the truth or falsehood of what that person says, or to the correctness of incorrectness of that persons’ reasoning.”
Take the hypothetical example of two political candidates debating welfare spending:
Candidate A: “I think that welfare spending should be cut over a period of time so that we can get people working again!”
Candidate B: “My opponents obviously hates the poor.”
No matter one’s opinion of the statement of the hypothetical Candidate A, it is clear to see that Candidate B did not, in fact, refute the argument made by his opponent. Instead he used an ad hominem attack.
The circumstantial type of ad hominem attacks (sometimes referred by the term tu quoque, “you also”) occurs when one attacks one’s opponent on the basis of their circumstances. For example,
Person 1: High school sports is a waste of time that distracts students from their academic work.
Person 2: My opponent has no right to say this because he is the president of the chess club.
Again, this type of attack is a fallacy as the circumstances of the person making an argument has no relevance to the truth or correctness of their argument.
Argumentum ad hominem are harm because they can winning arguments not by strength of reasoning but by affecting the psychology of the audience. They are a major fallacy that should be avoided if one wants to make sound, logical arguments in a respectful manner.
Bennett, B. (2013). “Ad Hominem (Abusive),” Logically Fallacious. Retrieved from http://www.logicallyfallacious.com/index.php/logical-fallacies/10-ad-hominem-abusive.
Copi, I. M. & Cohen, C. (1990). Introduction to Logic, Ed. 9. Macmillan Publishing Company: New York.
Lunsford, A. A. & Ruszkiewicz, J. J. (1999). Everything’s an Argument. Bedford/ St. Martin’s: Boston, MA.