When do the ends justify the means?

[Athene]

I only answered the hypothetical as it was presented in the OP. The child is alive, but soon to die and I have  the perpetrator with me. You've added several other factors to this hypothetical, enough to change it into a completely different scenario.

No I haven't, I've only extracted the logical conclusions.

If there is only one captor, you cannot know if the child is alive or not.

If there is more than one captor, and you only have one under torture, you cannot know whether the child is still in the same spot, as one of the henchmen may have moved the hostage.

I haven't added anything, but I have adduced a couple of things.

I can't imagine that most people wouldn't be willing to fuck up some guy, in order to find out where he stashed a missing kid. If it were there own child, even more so. The innate drive to protect their child would be all-encompassing, even as they knew what they were doing was wrong.

I'm a father, myself. While I would obviously do whatever I could to save my son, I wouldn't use torture to do so. It gives misleading information as often as it gives accurate information, and in a hostage situation, that would make torture counterproductive.

I'm against torture on moral grounds, but not on moral grounds alone.

I'm sorry if you take this to mean that I'm saying that torture is okay, because I'm not.