This study explores the increasingly troubled relationship between humankind and the Earth, with the help of a simple example and a complicated interlocutor. The example is a pond, which, it turns out, is not so simple as it seems. The interlocutor is Jean-Paul Sartre, novelist, playwright, biographer, philosopher, and, despite his several disavowals, doyen of twentieth-century existentialism. Standing with the great humanist at the edge of the pond, the author examines contemporary experience in the light of several familiar conceptual pairs: nature and culture, fact and value, reality and...