You are interested in proving that torture doesn’t work as a way of forcing them towards your moral conclusion. They will rightly suspect that your investigation of the factual question is not likely to be of a high quality. And indeed, that is what I find in these arguments: people wildly overstating an at best modest case that torture rarely produces all that much usable intelligence. [my emphasis]
While I can understand what might tempt you to write that passage, it just flat out begs the question. Of course one shouldn’t present an wildly overstated arguments. If you do, then your credibility should take a hit. But that point only matters if the arguments that torture don’t work are obvious crap. And no one making those arguments is going to think they are.
Now, many anti-torture commentators are being careless in their argumentation, and they might be letting their moral position confuse their factual judgment. In fact, I’d be astonished if that weren’t the case–it’s not as if human rights advocates are free from ordinary human frailties. What I don’t get is how the answer to that fact is to cede the field of debate. Then torture advocates get to assure us that torture is extremely effective, and the only way to safeguard America, but surprise–I don’t think they’re dispassionately evaluating the evidence either.
There some kind of extra scrutiny that you have to apply to yourself when you find that you’re arguing for something counter-intuitive that also would be very convenient to believe. Read charitably, that’s McArdle’s point, and she’s overstated it. But that doesn’t excuse you from exercising your judgment–you have to actually evaluate the evidence. If, upon reflection, you find that you’re unable to make a confident judgment, then you bow out of that particular debate. If you find that the evidence is completely equivocal, so that you suspect people will just read their biases into it, then you say that fact, and push back against anyone who is being confident, one way or another.