Topics Logic

Question I'd like to challenge the validity of the "Ad Hominem" fallacy - it seems to rest on a certain metaphysics. At the very least, this metaphysics should be argued, not assumed, in my view. The separation of a person from his/her ideas strikes me as certainly not obvious. Isn't this the reason why we urge people not to discuss religion and politics with each other? Because their views, expressive of their very identities, can offend us?

Accepted:
September 10, 2009

Comments

On the one hand, there is still a real fallacy of the sort we label ad hominem. The fallacy consists in claiming that a person's conclusion should be rejected because they have a bad character or have an ulterior motive. This is a fallacy because I don't have good grounds for saying that the conclusion is false. A bad person can occasionally offer a good argument, and a conclusion can be plausible even if it's argued for by someone of suspect character. Further, in the wild, so to speak, ad hominem arguments are often the last (or first) resort of intellectual scoundrels who want to divert attention from the poverty of their own case.

That said, there's a familiar sort of move that all of us make legitimately. Suppose, for example, that I am not an expert on some controversial topic, but I do realize that coming to sound conclusions is hard and that I'm not in a position to sort good arguments from bad. Suppose I come across an argument by someone who has something at stake, and who has a self-serving motive for convincing people that one side is the right one. This doesn't give me a reason to conclude that the person's arguments are flawed, and it doesn't give me evidence that his conclusion is false. But it does give me a reason not simply to accept what he says at face value.

There's no fallacy here. I am not drawing a conclusion about the arguer's conclusion itself. I'm merely appealing to the pedestrian fact that people with ulterior motives sometimes shade the truth or even lie. I have a legitimate reason to be cautious about accepting what this particular arguer says, and so long as I leave it at that, I haven't crossed the logical line.

Now of course, there is an even stronger sort of case that comes up occasionally. We may know that someone is an habitual liar on certain matters, and that far more often than not, when they offer arguments or claims on certain topics, the arguments are sophistical and the claims suspect. In cases like that, I have a sort of inductive reason for doubting the person's conclusion or being suspicious of the goodness of their argument, even if I can't see immediately where the flaw is. But this isn't the ad hominem fallacy. It's a legitimate case of probable reasoning. Needless to say, one ought to be careful in reasoning this way. One can deceive oneself about the depth of other's malignity and the extent of one's own virtue. But the logical point remains.