The Shafi‘i school of fiqh is named after Imam ash-Shafi‘i. The Shafi‘i School of thought stipulates authority to four sources of jurisprudence, also known as the Usul al-fiqh. In hierarchical order the usul al-fiqh consist of: the Quran, the Sunnah of Prophet Muhammad, ijma' "consensus", and qiyas "analogy".
The Shafi‘i school also refers to the opinions of Muhammad's companions (primarily Al-Khulafa ar-Rashidun). The school, based on Shafi‘i's books ar-Risala fi Usul al-Fiqh and Kitab al-Umm, which emphasizes proper istinbaat (derivation of laws) through the rigorous application of legal principles as opposed to speculation or conjecture.
Imam Shafi‘i approached the imperatives of the Islamic Shariah (Canon Law) distinctly in his own systematic methodology. Imam Shafi‘i, Imam Malik and Imam Ahmad ibn Hanbal almost entirely exclude the exercise of private judgment in the exposition of legal principles. They are wholly governed by the force of precedents, adhering to the Scripture and Traditions; they also do not admit the validity of a recourse to analogical deduction of such an interpretation of the Law whereby its spirit is adopted to the special circumstances of any special case.