You can't stop at just one.

Let's say you're against torture, but you want to accommodate the hypothetical ticking time bomb scenario. You know the one: there's a tremendous bomb set to go off in a major city in the near future, and there is someone in custody who knows where it is. Torture is used to compel this person to divulge the location of the ticking bomb in the short time available. To allow this exception, you write the law so that it says "no torture" except when there's an emergency which demands it.

Israel had a law like this in January 1999:

ISRAEL DOES NOT CONTEST REPORTS THAT SHIN BET AGENTS HAVE USED TACTICS SUCH AS VIOLENT SHAKING, SLEEP DEPRIVATION, CONFINEMENT IN TINY SPACES, AND EXPOSURE TO HEAT AND COLD IN THEIR INTERROGATIONS OF MAINLY-PALESTINIAN SECURITY SUSPECTS.

BUT IT DENIES THAT THE USE OF OF PHYSICAL PRESSURE ON PRISONERS IS SYSTEMIC, AND SAYS IT IS ONLY APPLIED IN SO-CALLED "TICKING BOMB" CASES IN WHICH IT IS IMPERATIVE TO EXTRACT INFORMATION TO AVOID LOSS OF LIFE.

Now let's say you have someone in custody who you suspect has done something wrong. Is there a ticking bomb? You can't tell for sure, but there could be. You and the prisoner both know that if there is a ticking bomb, torture will ensue. So if there is a ticking bomb, you can be darn sure the prisoner won't tell you about it, but you really have to know—right away—whether there is an imminent threat. How do you get the truth quickly in an emergency situation? Wait, I have the law right here...oh, yeah. "Pain accompanying serious physical injury, such as organ failure, impairment of bodily function, or even death."

I'm not making this up. From Why ticking-bomb torture stinks:

The only democracy that has experimented with the ticking-bomb scenario is Israel. It sanctioned the use of "moderate psychological and physical force" in such cases. The experiment proved unsuccessful and illustrates an insidious danger. Torture can grow. Israel found it impossible to limit torture to the terrorist alone and ended up applying force to those it believed knew or could lead security forces to the terrorist. Eventually the Israeli Supreme Court found that the exceptional use of torture in ticking-bomb cases wasn't working, It was an exception that was becoming commonplace and the court put an end to it. It is also salutary to note that at least one prisoner died under interrogation, raising questions about the concept of non-lethal torture. Any form of torture risks the life of the person tortured, by way of heart failure or otherwise.

(Emphasis added.)

The court's decision was in September 1999, and it said something else I agree with:

If the Shin Bet believes it must torture a suspect to reveal the location of a "ticking bomb," the torturer would be put on trial, but a court might accept the argument that physical force was necessary.

If it really is a case of torture or die, make that case to a jury. If you're not sure a jury of your peers will sanction your actions, perhaps you should reconsider them.

One other thing I've always wondered about: does the ticking time bomb scenario apply to innocents? If you have someone who had nothing to do with the bomb plot but knows where the bomb, is it justifiable to torture that person? If terrorists abducted your child to keep you from telling the authorities about a plot you learned about, would you tell the authorities anyway? What if the authorities tortured you?

This gets pretty deep into lesser of two evils territory. Where is the line? Can you only torture the bomber? The bomber's assistants? People who had nothing to do with the bomb but are sympathetic to the bomber?

These are hard questions. But to help you answer them, I've brought a pair of pliers and a blow torch...