Many good and kind people were involved in the Inquisition. Some of the priests who had devoted their lives to their faith and to kindness to other human beings were leaders in torturing and burning people alive.

From their point of view, torturing others was their ultimate sacrifice for the Good Cause. They honestly believed that to be kind to heretics would be the worst kind of cruelty to them.

After all, by slowly torturing these people to death they were giving them a chance to repent and avoid an eternity in Hell. And they were taking action against other people being damned to eternal torture in Hell by digging out the heretics.

In fact, this argument is irrefutable. If an Inquisitor had shown simple mercy, he would have been favoring his own personal prejudice in favor of not hurting somebody to the much greater cause of stamping out heresy.

This is usually true when mercy is shown. If there is no reason to hurt somebody most sane people will avoid it. The only time you need to appeal to mercy is when there IS an excuse for hurting people. In war, the choice is often between the Cause and mercy, and mercy is often interpreted as treason.

But the fact is that throughout most of history most Great Causes have been wrong or not as important as people like the Inquisitors thought they were. If people were always right, there would be no need for mercy.

But in real history, people feel the need for "mercy" when they truly believe it is just a weakness, a prejudice which they should ignore. So in real history, human beings should have listened to that voice of prejudice rather than to whatever cause called them to brutality.