CALLOUS, adj.
Gifted with great fortitude to bear the evils afflicting another.
When Zeno was told that one of his enemies was no more he was observed to be deeply moved. "What!" said one of his disciples, "you weep at the death of an enemy?" "Ah, 'tis true," replied the great Stoic; "but you should see me smile at the death of a friend."
--Ambrose Bierce - The Devil's Dictionary