" For I wondered that others, subject to death, did live, since
he whom I loved, as if he should never die, was dead; and I wondered
yet more that myself, who was to him a second self, could live, he
being dead. Well said one of his friend, "Thou half of my soul"; for
I felt that my soul and his soul were "one soul in two bodies": and
therefore was my life a horror to me, because I would not live halved.
And therefore perchance I feared to die, lest he whom I had much loved
should die wholly. "

― Augustine of Hippo , Confessions