This is a remarkable book: a symposium proceedings volume that will also function as a graduate-level text. Dedicated to the great theorist S. Chandrasekhar, the book consists of ten well-written chapters that cover the essential tools of theoretical astrophysics. The first half of the volume is concerned with the theory of how stars work (structure, stability, rotation, magnetism, dynamics) and the latter half is mainly a survey of relativistic astrophysics. . . . Read it for a broad-brush view of what theorists are up to now and how they solve problems.--Journal of the British Astronomical Association The book as a whole should be a gift from every research supervisor to every new graduate student in theoretical astronomy.--D. W. Sciama, Science