It is the aim of this essay to examine and present in as concise a form as possible the principles and rules which guided and regulated men in their economic and social relations during the period known as the Middle Ages. The failure of the teaching of the so-called orthodox or classical political economists to bring peace and security to society has caused those interested in social and economic problems to inquire with ever-increasing anxiety into the economic teaching which the orthodox economy replaced; and this inquiry has revealed that each system of economic thought that has from time...