This book offers a detailed presentation of the theory of Muslim law (usul al-figh). Often regarded as the most sophisticated of the traditional Islamic disciplines, Muslim jurisprudence is concerned with the way in which the rituals and laws of religion are derived from the Qur"an and the "Sunna" - the precedent of the Prophet. Revelation, which is given to man to restore unity and help him achieve a just and devout order in society as well as in the soul, must be interpreted so as to render it practicable in every culture, while not betraying its spirit and immutable provisions. To achieve this, additional sources of legal authority are recognized, including consensus (ijma), analogical deduction (qiyas), public interest (maslaha) and local customary precedent (urf). In employing these, the jurist guards the five principles which it is the purpose of Islamic law to uphold, namely, the right to life, sound mind, property, lineage and religion. The book includes a discussion of modern tendencies in Islamic legal theory, including those related to the important concept of "ijtihad": the mechanism by which the jurist may arrive at new rulings, or determine that old rulings are in need of adjustment. At a time when many Muslim countries are moving towards the reintroduction of Islamic law, it is important that the principles and nature of this rich and diverse legal tradition be correctly understood, both by the legislators themselves, and by outside observers. Written as a university textbook, "Principles of Islamic Jurisprudence" avoids the use of unnecessary technical expressions and endeavours to use Western legal terms wherever these are appropriate, while remaining close to the Arabic sources.