While the heart does not reason like the mind, it does convey interesting proofs.
It is seen, for example, that no one is ever absolutely, finally happy. Indeed, we often think that one more possession, one more accomplishment, one more relationship, and then we will be happy. It comes to pass; still we long for more.
Why is this? Do fish seek happiness in this way, perpetually and without final satisfaction? Why should we, if we are only another kind of animal, find ourselves seeking happiness voraciously, even enshrining the search for it into law?
If there is no ultimate answer for us, to satisfy this innate and universal desire, where does the desire come from? Read a book – the characters are permitted to live happily ever after, satisfying their desire. Play a game – there is an object, a way to win, satisfying the desire of the players.
The heart, it is said, has a God-sized hole in it. St. Augustine said, “Our hearts are restless, until they rest in You.” C.S. Lewis said, “If I find in myself a desire which no experience in this world can satisfy, the only explanation is that I was made for another world.”
This is the proof of the heart, with which we are to love the Lord our God: That our hearts desire endless satisfaction, that they are parched and thirsting for want of a drink which only “being itself” could quench. Indeed, if we love anything else without loving Him, we will never be finally satisfied.