There are admirable traits common in all human beings until hatred invades a soul.
Through that hatred terrorists divorce themselves from the human family and in making their bombs they abandon all natural sense of empathy.
Then by exploding them, they admit and announce that they are now pathetically bereft of the human qualities with which they were born, exposing the ugly truth that they have dehumanized themselves.
What does a warped and gruesomely twisted soul look like?
Is it that picture of Dorian Grey? Does it appear as a torturing demon in Dante's Inferno or the visage of the greek snake-haired gorgon Medusa?
Most of us fortunately lack the imagination necessary to assign a face to pure evil because to visualize it would haunt our dreams. But we cannot escape the fact that evil threatens us all, and our best hope as a race is tirelessly spreading kindness until good becomes so dominant a trait that evil such as seen at the Boston Marathon is expunged from our genome.
Possible? Of course it is. We are far less bestial now than in centuries past. Speed the process. Actually, really, tirelessly practice aloha.