And I hate definitions! (Especially when they're definitions without a whole hell of a lot of differences......)

When is an ad hominem attack not an ad hominem attack?

According to many, when it masquerades as an attack on the argument, that's when. For example, when an (apparently and unabashedly) Stalinist Ethnic Studies professor attacked David Horowitz, she didn't call him a racist or a fascist. She merely couched her rhetoric as a disagreement in ideology:

I admire immensely his ideological and racial fascism and its centrality to intellectual diversity.

Hmm... Glenn Reynolds manages to mention Leon Kass without some ad hominem, sophomoric attack attached to Mr. Kass's name. Is he turning over a new leaf?

Calling an argument "sophomoric" without citation or explanation of why it's shallow and immature is an ad hominem attack. This makes the additional complaint about ad hominem attacks disingenuous. The failure to provide examples makes the assertions gratuitous as well.

Regarding your contention that calling an argument "sophomoric" is not ad hominem, if you also don't think calling an argument "fascist," "idiotic," "stupid," or "mean" would be ad hominem, then I could see the point you are trying to make. But the attacks would still be unsupported name-calling, and directing them to the argument does not alter their ad hominem nature.

Characterizing a person's argument in such ad hominem terms (especially without offering examples) commits the ad hominem fallacy by substituting personal characterization for relevant argument.

This is a definition thing. If you call an argument fascist, this is a very different thing than calling the person making it a fascist. Really. I promise it is.

The distinction that is being lost here is one of basic relevance. To hurl insulting or abusive language at a person's thoughts or ideas, while it might not be exactly the same thing as hurling abuse at the person himself, is nonetheless injecting irrelevancy into the argument, because such insults ("racist," "fascist," "homophobic," or even "sophomoric") do not illuminate anything or resolve the merits of any questions under discussion. This is especially true when the epithets are aimed not at a particular statement, but are meant to characterize all or most of that person's views.

While I do it myself (as I just referred to a professor I don't know as an "unabashed Stalinist"), I'm well aware of its limitations, and my limitations, and I do not admire the mediocrity of my arguments when I do so.

But to take this further, if I declare that a particular person always (or most of the time) holds bigoted views, is that really different than saying he is bigoted? I don't see how.

Sometimes it's done to save time, other times it's a way of preaching to the choir.

For the record, I'll repeat that I'd rather not do it at all, and I wish others would make similar efforts.

Definitions can be so sophomoric!

No really.

MORE: Glenn Reynolds links to James Q. Wilson's articulate defense of Leon Kass, AND FightAging.org's criticism of him. For the life of me, I fail to discern the sophomorism (although I'm a regular practitioner of the latter.... and I don't think examples are needed!)

REMINDER: Regular readers already know this, but Justin wrote a long response which goes to the merits of D.F. Moore's post. A lot of work and thought went into it, and if you haven't read it, it's a must-read.