In a series of remarkable developments in the 20th century and continuing into the 21st, elementary particle physicists, astronomers, and cosmologists have removed much of the mystery that surrounds our understanding of the physical universe. We now have mathematical models that are consistent with all observational data, including measurements of incredible precision, and we have a good understanding of why those models take the form they do. Although current theories will probably be superseded by better, more detailed theories as science continues to advance, the great success of contemporary models makes it likely that scientists are on the right track. In short, the cosmos is undoubtedly comprehensible. For those fascinated by how physics explains the universe and affects philosophy, Stenger's in-depth presentation, complete with an appendix of mathematical formulas, makes accessible to lay readers findings normally available only to professional scientists.