The study of Muslim thinkers' social thought plays a pivotal role in identifying the indigenous potentials of Islamic social sciences. In this context, Ayatollah Mirza Mohammad Hasan Shirazi stands as one of the most influential jurists and religious authorities of the recent era, whose social actions and initiatives provide a fertile ground for reconstructing an authentic social theory. This research aims to extract and reconstruct the dimensions of Mirza Shirazi's social thought based on the historical experience of his lifeworld, particularly through the two pivotal events of his migration to Samarra and the issuance of the tobacco prohibition fatwa. Employing a fundamental methodology, the study seeks to identify and systematize the epistemic and non-epistemic foundations influencing the formation of his social thought. Findings indicate that Mirza Shirazi's social thought is grounded in epistemic foundations such as the Usuli-ijtihadi school and the understanding of religious authority as an institution continuing the mission of the Infallible Imams. This thought took shape through interaction with the non-epistemic contexts of his time—including institutional stagnation in the seminary, religious fragmentation, and colonial domination. His social thought can be explained through three core categories: institutional reform and modernization of the seminary, strengthening Muslim social unity, and resistance against colonial hegemony. Together, these form a coherent framework aimed at "safeguarding the identity of the Islamic Ummah" and revitalizing its socio-civilizational capacity in the face of contemporary challenges.