There has been a concerted discussion in various blogs (for example: here, here, here, and here) over Catholic teaching on the issue of torture. Having given this more than a little thought, I make various conclusions:

• whatever the definition of torture is, it is certainly an intrinsic evil, since both an Ecumenical Council, and a Pope have said so;
• the definition of torture cannot be something like "the application of severe pain", since "severe" has no specific meaning;
• any argument which says something like "since the application of the death penalty is sometimes permissible, therefore torture — being less than death — must also sometimes be permissible" is an incorrect argument, since the death penalty is only permitted as a defence, and not as a punishment, and the argument thus radically confuses two different categories;
• the Church's previous attitude to torture can presumably be found in documents such as Ad Extirpanda, but this document has not been provided in English, and thus has not been closely analyzed;
• based on what the Council said, I hold that the definition of torture should be something like: the application of pain to someone that is not for their direct benefit;
• a common scenario is to image an Islamic terrorist who has knowledge of some bomb about to explode. I have not yet seen it taken into account that the terrorist may hold in conscience that the bomb should be allowed to explode. If so, torturing them would be doubly wicked, since it would be an attempt to violently coerce their conscience.