“Biophilia,” published in 1984, marks Wilson’s first tentative foray on behalf of conservation. He proposes the word “biophilia,” meaning love of life, as an umbrella term to describe what he sees as a deep and natural affinity between the human mind and the natural world. He sees it, for example, in the dominance of plant and animal forms throughout our arts and crafts, in the fact that human beings in both the tropical jungle and the urban jungle dream of snakes at night, and in the observation that, if at all possible, people will choose to live close to a green space and a body of water. He does not offer biophilia as a coherent scientific theory. His point is rather that we are not programmed — neither by evolution nor by culture — to live without the natural world. It is what made us and shaped us, and we ignore it at our own peril. As Wilson writes, “We are in the fullest sense a biological species and will find little ultimate meaning apart from the remainder of life.” It is not just that the Earth will become uninhabitable without the life-sustaining forces of rich and diverse ecosystems but that we, human beings, might not want to live on such an impoverished planet. Seen this way, conservation of the natural world is our most pressing ethical problem.