Christopher Beha, from Why I Am Not an Atheist: The Confessions of a Skeptical Believer :

I could tell that my foundation was sound. I just wanted to know what was underfoot. So I told myself, Suppose you start with love. That was the one clear and certain thing in my life. What would it mean to start there? To begin with the certain reality of that love and build whatever could be built on top of it? If I took this for true, what else would have to be true with it?

To believe in love — not as a physical sensation, a neurochemical process in the brain, an adaptive strategy blindly hit upon by the genes in control of us survival machines, but as a foundational reality — means abandoning strict materialism, for the kind of love I’m talking about simply can’t be reduced to physical processes. It also means abandoning the idealism that says that the world we experience is entirely or even largely our own creation, that we project upon the raw facts whatever meaning and value and order we find there. From this perspective, love is a “mood,” part of the subjective apparatus with which we take in the objects of experience. But to really feel love is to be certain that it is not simply a projection, just as to stand in the warmth and the light of the sun is to be certain that the sun exists outside ourselves.

This reminds me of Auden:

One bubble-brained creature said—
“I am loved, therefore I am” — :
And well by now might the lion
Be lying down with the kid,
Had he stuck to that logic.