Excerpt: "The Meaning of Marriage"

When I make a promise, I declare that my future with people who depend on me is not predetermined by the mixed-up culture of my tender years. I am not fated, I am not determined, I am not a lump of human dough whipped into shape by the contingent reinforcement and aversive conditioning of my past. I know as well as the next person that I cannot create my life de novo; I am well aware that much of what I am and what I do is a gift or a curse from my past. But when I make a promise to anyone, I rise above all the conditioning that limits me. No German shepherd ever promised to be there with me. No home computer ever promised to be a loyal help...Only a person can make a promise. And when he does, he is most free. 

Excerpt from "The Meaning of Marriage" by Tim Keller