This collection of 24 essays is a perfect introduction to the world of Lewis Thomas. Topics ranging from the riddle of smelling to nuclear proliferation carry the gentle, unassuming persuasiveness that characterizes the author's work. Here we are also introduced to the concerns that have distinguished Thomas' literary career: the natural altruism of organisms; the inter-relatedness of all creatures; the fragility of the human species; the uneasiness of life on a threatened planet.