In many texts, justice has been defined as granting equal right to the equal people and granting unequal right to the unequal people. Many researchers are of consensus on this definition. However, justice against the concept of equality is seeking for the clarification of justified inequalities and evasion from cruelty regardless of all the equal and unequal aspects among individuals. Hence, the development of a criterion for inequality is considered as the most significant content issues in regard with justice.
This article is to illuminate that determining this criterion is regarded a philosophical issue and it is in need of philosophical and theological analysis on the basis of religious texts. In this article, it has been generally investigated the issue in view of Allameh Tabatabaee in Al-Mizan and the results are as follow: 1. In the analysis of justice by Allameh, there is a theoretical gap, since he has not profoundly clarified the formal definition of justice. 2. Although the logic of distribution of right in social justice and Islamic legal justice are different from each other, Allameh has utilized both of the interpretations on the statement of inequality criterion among men and women. 3. Justice up to the formal definition limit is fundamentally considered a philosophical issue and discussing about the legal justice leads to the discussion on the issue of distributive justice and in this regard the philosophy of rights or that of jurisprudence should enter the depth of definition and complete it. 4. The legal differences between two genders are not merely measured by the scale of justice and injustice and they are of other criteria.