Al-Hurr al-Amili as one of the well-known narrators of the second half of the eleventh century, beyond his narrative figure is a theologian who has reasoned and defended Islam beliefs as a prominent Twelver Shi’a scholar in different ways. The purpose of the "Methodology of Theology" is exploring ways that in science of theology brings us to the purpose and goal i.e. deduction of ideas and their defending. In deduction, the narrator achieves a correct knowledge of the teachings of religion, and in defending, explains and adjusts and proves that knowledge and rejects the ambiguities and opposing beliefs.Al-Hurr al-Amili has used traditional and rational methods in deducing beliefs. In the traditional method, he only considers evidence-based as well as frequently reported traditions as a proof and does not consider the appearance of Quran and even the appearance of statements of the Prophet (PBUH) unless the interpretation of which is expressed by Imams (AS). In the rational method, he considers the authority of intellect in proving the narrative reason, and has utilized the theoretical, practical and instrumental functions in the service of intellect. Therefore, intellect and tradition are not relevant. He has benefited from theoretical intellect in employing implications and practical intellect in understanding the inherent good and evil of deeds and their derivations and instrumental intellect in adherence to the emergence, spiritual frequency and interpretation.