If we cannot know what's possible, then we are free to do that which is pulling our hearts and that which is life serving.

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.

In the late 1960s, there were alarming predictions that worldwide famine was around the corner. I wondered if humans had already lost the race, overrun the Earth's capacity. I let one question lead to the next, and unearthed information that would forever change my life: Not only is there enough food in the world to feed every man, woman, and child on Earth, there is enough to make us all chubby.

We can't see ahead of time what actions are going to be the ones that move history in dramatic ways.

I had left graduate school, determined that I wasn't going to do anything else to "save the world" until I understood how I could get at the underlying causes of deepening suffering. To do that, I had to start by admitting that I didn't know.

We are very much social creatures who model ourselves on one another.

Women can succeed in villages all over the world today without relying on heavy machinery or debt. They can take leadership roles in agriculture, eliminating hunger and inequity.