A friend has made the following rejoinder to my argument: Torture should only be used in rare, extreme cases and as a last resort.
My response is it doesn't address the heart of the matter. What is at stake is not the frequency of the action, but it's nature. If an act is intrinsically evil, then it can NEVER be justified-not even once. While this may be an unpopular position, it is not without precedent. Thinkers from such diverse traditions as Christian (St. Paul), Ancient (Plato), and Modern(Kant) have taken it.
Since I have only rejected arguments up to this point, let me put a few on the table. First: Let the bomb explode. Socrates said it was better to suffer injustice than to do it. This is an argument we should seriously consider, rather than dismissing it out of hand.
Second: Torture should never be done, but X is not torture. This would require a definition of torture and then a case by case study of particular acts like waterboarding, walling, etc. Luckily, the work is being done.
Having stated some positive arguments, let me return to the negative. I would oppose any argument (ends justify the means, last resort, double effect, or lesser evil) formulated to justify an intrinsically evil act. Such arguments only create more problems than they solve.