This text offers the life-long reflections of a Japanese scholar who pioneered the application of general equilibrium theory to international trade. The book combines standard topics on international trade with a discussion of the evolution of the theory and some discussions on topics like immiserizing growth. This book is presented in two parts. Part I examines the historical progression of international trade theory. Part II addresses the modern theory and developments of international trade. This book offers a comprehensive evaluation of the non-monetary problems of international economics.