Ali Shariati (Ph.D.) is a thinker who has tried to describe and introduce Islam in the context of socialism with sociological approaches and utilizing historical data and minimal philosophical views. In this endeavor, justice was a central concept shaping the ideal society of Shariati, called the Middle Ummah (Middle Community). By manipulating conventional socialism, using its various modes, and also incorporating Islamic beliefs into its structure, he tried to use socialism as a context for introducing Islamic vision to build an ideal religious society. In this religious ideal society characterized to be a dual-rooted one named “Classless Monotheistic Society”, justice was the spirit governing it, which tuned it with the system of creation. On the path to build a theory of justice shaping a classless monotheistic society, Shariati passes through the four stages of theorizing; however, contradictions appear in the stages more elaborated by him and a great deal of ambiguity is also seen where he has chosen to give brief explanations. Thus, Shariati’s theory of justice is an incomplete theory containing many innate contradictions and ambiguities. The flaw in Shariati’s justice theory is so serious that the authors claim that what is inherited from Shariati is not a coherent theory of justice; rather, it is an initial design of a theory of justice in the context of Islamic socialism.