Driving in my car on my way to a meeting on Friday, I happened to catch a popular NPR news analysis program, On Point. Host Tom Ashbrook was talking with political commentator and Yale University computer science professor David Gelernter on his newly published book, Judaism: A Way of Being.
Gelernter, a proponent of Zionism, provoked strong responses from some callers who disputed his conclusions and offered spirited counterarguments. Toward the end of the program, one Jewish caller criticized Israel for its treatment of Palestinians, pointing to her experiences traveling in Israel and the gulf she perceived there between biblical values and practice. Instead of responding to the issues she raised, Gelernter dismissed her with the epithet invoked all too often in debates over Israel. He condemned her as a self-loathing Jew, sneering that “the most vicious haters of the Jewish community are Jews themselves”.
In this on-air interview Gelernter committed perhaps one of the most common of fallacies: the argumentum ad hominem, which is an attack on the speaker, rather than on the substance of the speaker’s statements, for the purpose of discrediting the speaker and undermining the speaker’s arguments. The ad hominem takes many forms; in this case Gelernter used the technique known as “poisoning the well“. To poison the well, you present negative information about your opponent to damage his credibility in the eyes of your audience. (Incidentally, earning Fallacious Argument bonus points, Gelernter also utilized the false analogy, comparing the caller’s criticisms of Israel to blood libel and Nazism.)
Highly explosive, the ad hominem inflames passions and prejudices. When it detonates, it leaves a scarred chasm that cannot be bridged, making speakers and audience members into bitter partisans, with discourse and civility collateral damage. When the shouting at last dies down, all that’s left to smolder in the rubble is ill will.