Viktor E. Frankl in Man’s Search for Meaning p. 50

My mind still clung to the image of my wife. A thought crossed my mind: I didn’t even know if she were still alive. I knew only one thing — which I have learned well by now: Love goes very far beyond the physical presence of the beloved. It finds its deepest meaning in his spiritual being, his inner self. Whether or not he is actually present, whether or not he is still alive at all, ceases somehow to be of importance.

I did not know whether my wife was alive, and I had no means of finding out …; but at the moment it ceased to matter. There was no need for me to know; nothing could touch the strength of my love, my thoughts, and the image of my beloved. Had I known then that my wife was dead, I think I would still have given myself, undisturbed by that knowledge, to the contemplation of her image, and that my mental conversation with her would have been just as vivid and just as satisfying. ‘Set me like a seal upon thy heart, love is as strong as death.’”