Tortured Logic

As I mentioned lots of peoples are discussing torture in lots of unhelpful ways. Over to Crooked Timber a commentator makes this argument

I think it’s just obvious that torture can be effective, at least in the case where the information you’re trying to extract is immediately verifiable, like, say, the password for a document that is right here, in front of you. I think people understands this, and they probably take the line “we shouldn’t torture because torture doesn’t work” as an insult to their intelligence.

Much like the ticking time nonsense, this hypothetical assumes perfectly imperfect knowledge. The torturer is has perfect that the only missing piece of information is the password and that this person right here has it. Consequently torture is okay. How does the torturer know this? Because if he or she didn't the hypothetical falls apart.