The problem of sustainability is simple enough to state. It requires that the fertility cycle of birth, growth, maturity, death, and decay—what Albert Howard called “the Wheel of Life”—should turn continuously in place, so that the law of return is kept and nothing is wasted. For this to happen in the stewardship of humans, there must be a cultural cycle, in harmony with the fertility cycle, also continuously turning in place. The cultural cycle is an unending conversation between old people and young people, assuring the survival of local memory, which has, as long as it remains local, the greatest practical urgency and value. This is what is meant, and is all that is meant, by “sustainability.” The fertility cycle turns by the law of nature. The cultural cycle turns on affection.