There's a lot of research that suggests that organic yields are close or superior to conventional yields depending on factors like climate. In a drought year an organic field of corn will yield more - considerably more - than a conventional field; organic fields hold moisture better so they don't need as much water. It simply isn't true that organic yields are lower than conventional yields.

Very simply, we subsidize high-fructose corn syrup in this country, but not carrots. While the surgeon general is raising alarms over the epidemic of obesity, the president is signing farm bills designed to keep the river of cheap corn flowing, guaranteeing that the cheapest calories in the supermarket will continue to be the unhealthiest.

My hope is that if people have the knowledge, and if they actually see where their food comes from and have access to the information, they will make better ethical choices.

Stop eating before you're full.

A natural historian is somebody who looks at something in terms of its relationship to the rest of the natural world. You look at things ecologically. When you see a cow on a feedlot, you don't just see a cow; you see a cow that is eating certain food. You follow that food and that food takes you back to a corn field.

Eating is a political act.

The great virtue of a diversified food economy, like a diverse pasture or farm, is its ability to withstand any shock. The important thing is that there be multiple food chains, so that when any one of them fails-when the oil runs out, when mad cow or other food-borne diseases become epidemic, when the pesticides no longer work, when drought strikes and plagues come and soils blow away-we'll still have a way to feed ourselves.