Defending The Arguments for the Necessity of Infallibility of Imam to Clear up Fakhr-E- Razi’s Doubts

Contrary to Sunny scholars, Shia scholars believe that infallibility and immunity of Holy Prophet's successors (peace be upon him and his progeny) from any mistake, sin, error, and fault is a necessary and essential condition. Therefore, Imams (peace be upon them) must be infallible and immune from any sin and error. Shia theologians and scholars, particularly Khawja Nasir al-din Tusi, have provided several transmitted and rational arguments for the necessity of infallibility of Imams (peace be upon them) who are the successors of Holy Prophet. Therefore, any neglect of divine injunctions and commands, whether intentionally or unintentionally, overt or covert, is inconsistent with taking the position of Imam and succeeding Holy Prophet.  Fakhr Razi and his followers, however, cast doubt on and even denied the necessity of the condition of infallibility for Holy Prophet's successors and finally reduced infallibility into justice. The present paper elaborates on the most important arguments of Muslim theologians, particularly Mohaqqeq Tusi, for the necessity and exigency of infallibility of Imams, criticizes and rejects Fakhr Razi's most important doubts and objections, and finally concludes that infallibility is a necessary and essential condition for Holy Prophet's successors.