Notes on Levin's "The Case For Torture"

Levin's argument is that torture is justifiable when it is used to prevent loss of life, such as in extracting information about where a bomb is planted from the person who planted the bomb, or in finding out where a kidnap victim is held from a kidnapper.

The obvious argument against this (which he mentions) is to point out that there is no guarantee that a person apprehended for a crime is actually the perpetrator.

Levin's defense is that, in cases of terrorism, you always know who the perpetrators are. Really. This is his actual argument. (Though he tosses in a saving clause that you should only torture those who are obviously guilty.)

So, to boil down Levin's arguments:

Torture is justifiable when 1. There is an immanent threat of loss of life 2. The authorities have apprehended a person whose knowledge may prevent this loss of life 3. The person apprehended is (or will be) guilty of murder. 4. The authorities can know without a doubt that the person is guilty.

This, of course, presupposes that the police (or whoever) have never and will never have a case of mistaken identity.

Also, what constitutes a credible threat, that would make torture admissible?

Also, how often have the above four requirements all been met, outside of the movies?