Thermodynamics is a field of very broad application, as it is of fundamental importance in physics, chemistry, and related areas of engineering. This book presents a novel treatment of thermodynamics that is more rigorous, more complete, and easier to understand than the conventional treatments presented in the vast majority of existing textbooks. Beginning with a few assumptions based on empirical results, the entire theoretical framework of thermodynamics is derived in an intuitively clear, logical manner, leaving no important questions unanswered. Each step in the book's construction of this theoretical framework is grounded in clearly explained physical considerations. In addition, the text also presents philosophical discussions that elucidate fundamental points of science and clarify the status of thermodynamics within science as a whole. Aimed at undergraduate students, graduate students, and researchers in physics, chemistry, engineering, and related areas, the book includes numerous exercises to provide a deeper understanding of the fundamental theory and its applications.