Ijtihad conducted by Ali ibn Abi Talib continuously to understand in depth the purpose of Islamic law and reason for its implementation, and to realize maslahah (the public good) for human life on earth. This Ijtihad was always supported by nas the Qur’an’s and Sunnah’s text) and also according to the spirit of Shari’ah. The results of Ali’s ijtihad if linked with the approach and application of maqasid al-shari’ah (the goals and objectives of Islamic law) as the study of usul al-fikih (the methodology of Islamic law) had many similarities. In another sense, Ali ibn Abi Talib was really smart to understand and apply maqasid al-shari’ah in the five types of maslahah, namely faith or religion, life or human self, intellect, lineage or posteri...