The moment . . . the very MOMENT . . . that a debater goes ad hominem reveals that (1) he feels terribly threatened and (2) he does not feel comfortable merely arguing the factual/logical case.
All a positional proponent needs do is argue his own case. The use of ad hominem attacks against foes is a giveway about the weakness that the proponent feels about his own case.
Doesn’t matter if we’re talking pro or anti theism, pro or anti evolution, pro or anti ANYTHING. Any topic, anywhere, any time.
It also makes profound statements about someone’s character, too. And those statements are not positive.
Usually true, except when the ad hominem charges are those pertinent to a moral issue, i.e. Mt. 23