After the journey around the world, writing Hope's Edge, I began to see that it is not possible to know what's possible - and therein lies our freedom.

On the one hand, our social nature is our greatest beauty - it means that we have natural empathy and sympathy. But our social nature also means that we may let ourselves be controlled by the judgments of others, precisely because we care so much about our status in community.

Food has always been at the center of community bonding, of family life, and simple pleasure, but it is becoming more and more an obsession, a source of pain.

I think of Wangari Mathai in Kenya. If she started out saying she wanted to plant 20 million trees, she would have been laughed at. In fact, the foresters and the government did laugh at her. They said, "Villagers? Un-schooled villagers? Planting trees? No, no, no, it takes foresters." So she planted trees anyway.

I think that fear of embarrassment is the essence of the human challenge.

Approaches to growing food that align with nature changed human relationships.

This is the first generation to know that the choices we're making have ultimate consequences. It's a time when you either choose life or you choose death ... Going along with the current order means that you're choosing death.