The Influence of the Role of Prevailing Custom in theJurisprudential Ruling of the Theory of Compensation of the Depreciation of Money

There are a large number of jurisprudential issues which the divine law giver has not clarified their significations nor their extensions, hence referring them to the prevailing custom. One of these issues is token money and its depreciation. Such concepts astoken money, depreciation of money, settlement of the debt, and demanding extra are all matters of prevailing custom and their significations as well as their extensions are referred to the prevailing custom. The question is whether in case of settling along- term monetary liability concurrent with the depreciation of money, the nominal value of the bill, i.e. the figures inscribed on it, should be taken into account Is this idea supported by the prevailing custom and behavior of the reasonable? Or it isnecessary to consider the real exchange value and the real purchasing power of the amount borrowed? In spite of the dominant view of jurisprudents concerning the religious prohibition of demanding anything more than the nominal value, the articleproves the hypothesis that firstly what customarily motivates people towards token money is the purchasing power and the exchange value of money, not its nominal value. So this point should be taken into consideration while settling the debt.Secondly, custom or reasonable behavior does not accept the theory of compensation of the depreciation of money absolutely and in all cases of inflation. Rather, it has shown different reactions towards different rates of inflation issuing a particular ruling in each case