There is, quite obviously, a desperate need to believe that when an American engages in acts of violence of this type (meaning: as a deviation from formal American policy), there must be some underlying mental or emotional cause that makes it sensible, something other than an act of pure hatred or Evil. When a Muslim engages in acts of violence against Americans, there is an equally desperate need to believe the opposite: that this is yet another manifestation of inscrutable hatred and Evil, and any discussion of any other causes must be prohibited and ignored.