Was the Gate of Ijtihad Closed?

As conceived by classical Muslim jurists, ijtihād is the exertion of mental energy in the search for a legal opinion to the extent that the faculties of the jurist become incapable of further effort. In other words, ijtihad is the maximum effort expended by the jurist to master and apply the principles and rules of uṣūl alfiqh (legal theory) for the purpose of discovering God's law.1 The activity of ijtihad is assumed by many a modern scholar to have ceased about the end of the third/ninth century, with the consent of the Muslim jurists themselves. This process, known as ‘closing the gate of ijtihad’ (in Arabic: ‘insidād bāb al-ijtihād’), was described by Joseph Schacht as follows: