The session looks at how, with the human family pressing against planetary limits, perpetual expansion is no longer a viable goal. The changing relationships with the Earth, from the Earth being enormous compared to human activity, to humanity rivalling the integrity of the natural world, requires a different approach to mutual provision (the economy). The human family has reached physical maturity and, as with individual maturity, accepting responsibility for our strength is accompanied by the vast opportunities of adult life. By focusing on what we can do with our lives, rather than with stuff, we can have more fulfillment with less impact on the environment. Time tested biological processes can secure long-term well-being as society's economic “metabolism” adapts to our new situation. A shared vision of the new goal can lead to a sustainable future.