I'm having trouble finding a piece which I am fairly confident was either written on LW or linked to from here. It dealt with a stone which had the power render all the actions of the person who held it morally right. So a guy goes on a quest to get the stone, crossing the ocean and defeating the fearful guardian, and finds it and returns home. At some point he kills another guy, and gets sentenced by a judge, and it is pointed out that the stone protects him from committing morally wrong actions, not from the human institution of law. Then the guy notices that he is feeling like crap because he is a murderer and it is pointed out that the stone isn't supposed to protect him from his feelings of guilt. And so on, with the stone proving to be useless because the "morality" wasn't attached to anything real.

If somebody knows what I'm talking about, could they be so kind as to point me towards it?