The book, first published in 1906, outlines the religious, ceremonial, civil and moral laws and regulations of Islam. The four sources from which the doctrines and precepts of Islam are founded are the , the and the . This title also interprets the principles of the four sources in respect to , or positive knowledge, and , or understanding. It is with these aspects of Islamic theology and law that this book is concerned. This book will be of interest to students of theology and religious studies.