Based on the Gibbs maximum- entropy formalism, this statistical mechanics text offers the most direct, precise, and comprehensible foundation for the development of thermal physics, both macroscopic and statistical. Presenting a general entropy- maximizing variational principle for thermostatics and equilibrium statistical mechanics, the book also covers modern topics of phase transitions, critical phenomena, renormalization, interacting systems, and more. Of interest to physical chemists and professional physicists who need to update their reference libraries.