If it works, some argument can be made about "the suffering of one for the greater good of the many". The common example is the terrorist that knows the locatio

If it works, some argument can be made about "the suffering of one for the greater good of the many". The common example is the terrorist that knows the location of a bomb that may kill thousands of people. Also torture is made acceptable to some by the idea that only "bad" people are tortured. If torture doesn't work, the argument is much stronger than the humanist one and can appeal even to "us vs them" people. Unfortunately I think the reason many governments torture is not to gather information but to frighten and control the population. Many people will refrain to rebel against authority if they fear being arrested and tortured.