This book is an in-depth study on the birth of the science of philosophy of Islamic law (ʿilm al-maqāṣid) from the time of Imam al-Shātibi to the present day. It addresses and explains, in great detail, three of the discipline’s pillars and rules, namely: the rule of taʿlīl, i.e. causation; the rule of istislāh, i.e. deriving the ruling based on achieving the benefit (maṣlaḥah mursalah) in the absence of a text; and the rule of ma’ālāt, i.e. considering the consequences. In his study, the author also proves the independence of the science of philosophy of Islamic law (ʿilm al-maqāṣid) until it became an actual and indisputable reality. Today, this discipline has its eminent authorities, history, issues, publications, branches and areas, principles and rules, and distinct functions… Hence, it no longer lacks any of the features of an “independent science”.