Angel or Duke?

I have a friend who lives in an apartment with shelves full of books and walls covered with photographs of friends.

And a cat, and some days, a smiling, happy daughter. And they learn together how to draw a face and how to spell a word, as if he never knew and he is also in the first grade. And even when he’s not at his best, you can sense that it’s an exception—he comes back without pretending and shouts, “I’m fine, I’ve never been better!” His brain defies the law of diminishing returns as you grow old; it is still fruitful and open to discussing almost everything with genuine interest.

Of course, we cannot arrange a proper meeting—the other day, I went to his home with my son only to find out that his daughter was not there. And, of course, we disagree. How else could I dare to call him a friend?