Does human existence exert a selection effect when assessing observed properties of the universe? That is what this scholarly tome by astronomer Barrow and mathematician Tipler is all about. To some extent the authors are dealing with traditional metaphysical problems concerning reality: How does the nature of human information-gathering processes affect what is perceived? Is the structure of the universe independent of intelligent observers? Or is the evolution of the universe intimately linked to the evolution of higher intelligence? The latter belief supposes that there are unique properties of hydrogen, carbon, oxygen, nitrogen and other elements which, combined with Earth's size and distance from a medium-sized star like the sun, have led to the special evolution of man. By this reasoning, intelligent observers are virtually unique in the universe, the product of a chain of improbabilities. Or maybe not improbabilities. . . For some, such reasoning leads to the conclusion that some High Force is at work. The authors argue that even if non-carbon-bound life exists in the universe, the fact remains that we view the universe through carbon-colored glasses. Thus we must recognize at least a Weak Anthropic Principle (WAP) in making judgments about the nature of the universe. Others go so far as to state that well-known physical constants (like the force of gravity) and physical ratios (such as the mass of a proton to an electron) are essential to the existence of a carbon-based universe and also imply that the universe must be a certain age and size. These deductions have led to the positing of a Strong Anthropic Principle (SAP), that the Universe must be such as to admit the creation of observers within it at some stage. The mathematical and cosmological arguments mount to a climax in a Final Anthropic Principle (FAP), according to which life never dies out and for which several testable hypotheses are offered. All rather heady stuff here, presented in a no-nonsense lecture style that has the authors advising readers to be self-selective themselves and skip the math, if they like. Even so, a book clearly targeted for the committed cosmologists, whether dedicated to WAP, SAP, FAP or not.