This is an accepted version of this page Shaykh Tusi (Persian: شیخ طوسی), full name Abu Ja'far Muhammad ibn al-Hasan al-Tusi (Arabic: ابو جعفر محمد بن الحسن الطوسي, romanized: Abū Jaʿfar Muḥammad ibn al-Ḥasan al-Ṭūsī), known as Shaykh al-Ta'ifah (Arabic: شيخ الطائفة, romanized: Shaykh al-Ṭāʾifah) was a Persian[1] scholar of the Twelver school of Shia Islam.
Tusi had an important role in the formation and revival of Shia jurisprudence and law, as his life coincided with the burning of books and libraries.
One of his main accomplishments was that he was successful in propagation and making his methodology of argumentation and inference coherent: he had given to Shaykh Mufid a definite formulation of ijtihad.
He started developments that allowed Shia clerics to assume some of the roles previously permitted to only imams, such as collecting and distributing religious taxes, and organizing Friday prayers.
[21] His emphasis was on the rational dimension of religion, underlining that principles like the commandment to good and prohibition of evil are indispensable according to reason.
[24] Tusi wrote over fifty works in different Islamic branches of knowledge such as philosophy, hadith, theology, biography, historiography, exegesis, and tradition.