I recently handled the revisions on a paper that hopefully will be in press very soon. One of the review comments was “Be very careful not to make ad hominem attacks”.

I was a bit surprised to see that — I wasn’t aware that I’d made any — so I went back over the manuscript, and sure enough, there were no ad homs in there.

There was criticism, though, and I think that’s what the reviewer meant.

Folks, “ad hominem” has a specific meaning. An “ad hominem attack” doesn’t just mean criticising something strongly, it means criticising the author rather than the work. The phrase is Latin for “to the man”. Here’s a pair of examples:

• “This paper by Wedel is terrible, because the data don’t support the conclusion” — not ad hominem.
• “Wedel is a terrible scientist, so this paper can’t be trusted” — ad hominem.

What’s wrong with ad hominem criticism? Simply, it’s irrelevant to evaluation of the paper being reviewed. It doesn’t matter (to me as a scientist) whether Wedel strangles small defenceless animals for pleasure in his spare time; what matters is the quality of his work.

Note that ad hominems can also be positive — and they are just as useless there. Here’s another pair of examples:

• “I recommend publication of Naish’s paper because his work is explained carefully and in detail” — not ad hominem.
• “I recommend publication of Naish’s paper because he is a careful and detailed worker” — ad hominem.

It makes no difference whether Naish is a careful and detailed worker, or if he always buys his wife flowers on their anniversary, or even if he has a track-record of careful and detailed work. What matters is whether this paper, the one I’m reviewing, is good. That’s all.

As it happens the very first peer-review I ever received — for the paper that eventually became Taylor and Naish (2005) on diplodocoid phylogenetic nomenclature — contained a classic ad hominem, which I’ll go ahead and quote:

It seems to me perfectly reasonable to expect revisers of a major clade to have some prior experience/expertise in the group or in phylogenetic taxonomy before presenting what is intended to be the definitive phylogenetic taxonomy of that group. I do not wish to demean the capabilities of either author – certainly Naish’s “Dinosaurs of the Isle of Wight” is a praiseworthy and useful publication in my opinion – but I question whether he and Taylor can meet their own desiderata of presenting a revised nomenclature that balances elegance, consistency, and stability.

You see what’s happening here? The reviewer was not reviewing the paper, but the authors. There was no need for him or her to question whether we could meet our desiderata: he or she could just have read the manuscript and found out.

(Happy ending: that paper was rejected at the journal we first sent it to, but published at PaleoBios in revised form, and bizarrely is my equal third most-cited paper. I never saw that coming.)