The subject of this volume is the human economy and its coevolutionary relationship with the natural world. This relationship is examined in three broad types of societies; hunter--gatherers, agriculturalists, and modern market economies. A growing body of scientific evidence has made it clear that the current human impact on the environment is far above the level that can be maintained without causing profound changes in the biophysical world to which we belong. The new fields of ecological economics and evolutionary economics can help us understand the relationship between the economy, society and the environment and may help us to formulate effective policies to manage these changes.