Add to ORKGIncludes bibliographical references (page 583).Ecology is the logic of living creatures in their homes. Ecology mixes with ethics, an ecological (or environmental) ethics urging that humans ought to find a lifestyle more harmonious with nature. Humans have always had to rest their cultures on a natural life support system. Environmental engineers may now claim that the principal novelty of the new millennium is that Earth will be a managed planet. Such claims bring increasing concern how far nature can and ought be transformed into humanized nature. Thinking of humans as fitting themselves into a sustainable biosphere is a better logic of being at home on Earth