ad hominem

Ad hominem literally means "to the person" in New Latin (Latin as first used in post-medieval texts). In centuries past, this adjective usually modified "argument." An "argument ad hominem" (or "argumentum ad hominem," to use the full New Latin phrase) was a valid method of persuasion by which a person took advantage of his or her opponent's interests or feelings in a debate, instead of just sticking to general principles. The newer sense of "ad hominem," which suggests an attack on an opponent's character instead of his or her argument, appeared only in the last century, but it is the sense more often heard today. The word still refers to putting personal issues above other matters, but perhaps because of its old association with "argument," "ad hominem" has become, in effect, "against the person."