This is not so ranch a finished work as it is a collection of thoughts, or thoughts-in-process of becoming formal essays. The separate chapters contain brief summaries of the main achievements of 20th century science coupled with expressions of hope and anxiety for man's future. Shapley's main thesis concerns cosmic evolution and human anthropocentrism. He sees certain unities in the evolution of stars and of organic life; of the structure of the universe and the structure of the atom. Religions, he believes, should not be static, but keep in step with the cosmic changes visible in man, nature, matter. He espouses a kind of existential pantheism, a belief in all things that are, and he is worried that the particular experiment that has led to human existence on earth is in danger of running itself into the ground. In the final sections of the book he explores the Book of Job, addresses himself to a comet flying by the earth, and speaks to man in general and the young scientist in particular. It's hard to get upset with the essential beliefs of this elder statesman of astronomy--that the fighting must stop, that man should turn his attention to eradicating poverty, starvation, ignorance, suspicion, and the suppression of human rights--but the loose and sketchy structure of the book, and the tone, at times flippant, at times hortatory, are disappointing.