Explore the foundations of quantum field theory with The Quantum Theory of Fields by Nobel Laureate Steven Weinberg. This two-volume work is a comprehensive and up-to-date introduction to quantum field theory with Volume I introducing the basic principles and properties of particles. Weinberg presents classic calculations and reflects changes in our view of quantum field theory in recent years. This work is suitable for physicists, mathematicians, and graduate students looking to deepen their knowledge of the subject.