The Scope of Infallibility of the Prophets in the Eyes of Nasir al-Din Tusi

Regarding fallibility of the Prophets, Nasir al-Din Tusi believes that they are infallible in theoretical domain in receiving, maintaining and conveying the revelation and no error and wrong is made by them purposefully or unpurposefully. In his view the Prophets are also infallible in in practical levels in respect with both mortal and minor sins, before and after being chosen as prophet. Thanks to the grace of Allah they are immune from any fault and mistake in their judgments and perception of the subjects of religious rulings, social problems and cognizance of interests of society as well as daily affairs of life. Tusi regards infallibility as an act of Divine grace for those are endowed with such characteristic. Although infallible man is able to commit sin, he is encouraged to do acts of obedience and avoids disobedience. The purpose of prophets is gained only if they are trustworthy and this cannot be unless they are infallible. To him infallibility is absolutely essential on both revealed and rational bases. In explaining the former, Tusi appeals to some Quranic verses which state Satan in incapable of misguiding the purified chosen men of God and that His covenence does not reach the unjust people. Necessity of having trust in prophets and disobeying them in case of their being wrong and fallible can be taken as rational arguments for the doctrine in question.