In this volume, two classical texts of legal theory (""usul al-fiqh"") are analyzed. The authors of these works belonged to two schools of Shii jurisprudence: Yusuf al-Bahrani (d.1186/1772) was a key figure in the ""Akhbari"" school, and his adversary, Muhammad Baqir al-Bihbahani (d.1206/1791-2) was credited with the revival of the ""Usuli"" school and the defeat of Akhbarism after Bahrani's death. Through a comparison of the two writers' theories, this work describes the major areas of dispute between the two schools, examining how their different epistemologies lead to different conceptions of the sources and interpretation of the Sharia, God's law for humanity.