Principles of Jurisprudence (Usül al-Fiqh) is originally written by the great Muslim thinker and reformer Äyatulläh Murtadä Mutahhari on principles of Islamic jurisprudence for B.A students at the faculty of theology of the University of Tehran. This book deals with such topics as the definition of Usül al-Fiqh and its sources, a brief history of Usül al-Fiqh, The binding testimony of the Qur'an's apparent and accepted realities (zawähir), issues common to the Qur'an and the Sunnah, consensus and reasoning and the principles of application.