The study of economic thought is the study of the philosophies of different thinkers and theories in the subject that later became political economy and economics.  Understanding about the origin and development of economic ideas and their interrelations. Familiarity about how economic thought has evolved overtime with a critical comparison of the major contributions. Learning of the fact that history of economic ideas is different from economic history and history of economics.  Understanding of the ancient and medieval economic thoughts, such as Mercantilism and Physiocracy.  The study of economic thought is important as it connects us with the ancient times and helps us to understand the origin of economics.