No...just evil.
In these cases, insane is just an excuse. Evil, corrupt, twisted, yes. But not insane.
You would have definitely had to have lost your soul, (ie, be evil) to actually *do* something like that. However, Doughty One's question had to do with "getting it", or understanding the why. This indicates, at a minimum, loss of sanity, if not actual loss of human soul, so I stand by my comment...
the infowarrior