But the American-born cleric argues that these methods of suppressing heresy were explicable in the context of the times, when people believed passionately in heaven and hell.

Now this is interesting. The excuse is that this torture is explicable when individuals passionately believed in heaven and hell. I suggest that this fact should make it all the more inexplicable...

For no matter how enjoyable some people may find inflicting pain on others - few I suspect would consider it to be a good thing. Now how come all those involved in this suppression of heresy could undertake these bad things in its name - when they did so passionately believe in heaven and hell? They would know their fate for doing these bad things would be eternal damnation in hell. Or did they?

I am not sure thinking something like the Inquistion to be explicable makes any of it any more excusable. For it rather depends on what that explanation is.