This chapter is devoted to Allame Mohammad Hossein Tabatatabai's (hereafter referred to as M.H.Tabatabai) theory of justice. M.H.Tabatabai's main contribution to the field of practical philosophy is his theory of artificial conceptions (edrakat-e etebari). Commentators have developed a variety of interpretations about the meaning and implications of this theory. My arguments in this chapter follow a less theologically oriented line of interpretation concerning this theory, which started with Motahari before the revolution, before being expanded by Soroush and his students in the post-revolutionary era, in that I defend a post-Islamist contractarian interpretation of Tabatabai's theory of artificial conceptions. I aim to demonstrate that the new contractarian reading of Tabatabai developed is plausible because it is well supported by the textual evidence. This chapter includes a comparison of Rawls's contractualist and Tabatabai's contractarian approaches to justice, and their respective relationships to religion. It ends with a discussion on the role of colonialism and the historical context in M.H.Tabatabai's theoretical oscillation between the ideas of democratic contractarianism and Islamic State.