One of the most important and famous sciences in the field of tradition studies is the study of Rejal (Narrators of Hadiths) which dealss with the narrators’ status to ensure that the narrated traditions (Hadiths) are issued by the infallibles. Mohammad Taqi Shoushtari was an outstanding contemporary biographical evaluation scientific who had critical viewpoint in this field. His Qamoos al- Rejal, in fact, was a criticism to Mamaqani’s Tanqih al- Maqal. Shoushtari criticized the mistakes done by Mamaqani in applying and referring to the former Rejali sources which led to other misunderstandings. For instance, Mamaqani without noticing the differences between the former sources has equally applied all sources while noticing the differences plays an important role in applying them. This article studies the principles and methods of applying the Rejali sources to discover the narrators’ religion and status, narrating from the infallibles, methods of recognizing the common points, the unity of the differences, and the authority of the sources.
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