Nowadays, the economic independence is of great importance. A country possessing economic independence can also protect its political and cultural independence. But intellectual independence is even prior to economic independence; and considered the origin of all affiliations, even the economic and intellectual affiliation. In the field of economy, we posses intellectual independence just when we are able to discover and design a suitable economic system which is based on the weltanschauungand values and ends which are considered in the school of Islam. The writer tries to explain the system of economy of Islam and wants to compare it with capitalist system and mostly opposing the liberal capitalism. The writer believes that the liberal capitalism is based on special philosophical and ideological essentials and apparently possessing special versatility. The writer in this volume which is the first of the four volumes is trying to not only define the system of the economy and its essentials and ends and its affiliation with economics and economic law, but also to discuss and evaluate the philosophical essentials of system of Economy of Islam comparing with the liberal capitalist Economic system.