Salam Dear Muhammad,
Thank you for this good question, which reflects deep insight and true search for knowledge, along with good understanding of the teachings of Islam.
Actually, the word ijtihad is an Arabic word taken from the origin jahd, which means exerting efforts. In the juristic sense, ijtihad is the legal process in which the jurist practices his own reasoning based on the Shari`ah stipulated conditions to derive or produce the rulings pertaining to issues in conformity with the general spirit of Shari`ah and its objectives.
"Ijtihad therefore is an exercise of one's reasoning to arrive at a logical conclusion on a legal issue done by jurists to deduce a conclusion as to the effectiveness of a legal percept in Islam." (Sari`ah; The Islamic Law, by Abdur Rahman I. Doi)
In fact, allowing ijtihad is one of the most important characteristics of Islam since it shows the flexibility of the Islamic Shari`ah and its suitability to all times and places.
Ijtihad is really important to offer solutions and to provide the perspective of Shari`ah in any new issue, since Muslim jurists agree that "the more people live, the more they get new issues and new rulings for these issues."
With the amazing progress in technology and science, people face new problems and need solutions for them. They will turn directly to Shari`ah for consultation and guidance. If Shari`ah is unable to provide solutions and answers, this will be considered a big deficiency in the sense that it will not be considered valid for all times and spaces.
Thus, to close the door of ijtihad is to say that Islam is not above time and space factor, which is rejected totally.
Who Can Practice Ijtihad?
When we say that the door to ijtihad is not closed we do not open it for everyone. Shari`ah is not open for tampering or every passer by. It is only scholars who are well-versed with Shari`ah that can practice ijtihad. The one who practices ijtihad is called mujtahid. There are certain conditions for a mujtahid, which should include the following:
- He must be well versed with the Quran, the reasons and occasions of revelation and the rulings of general and specific (`aam and khaas) and the rulings of abrogation.
- He must know the Sunnah, the classification of Hadith, the ways of narration and the science of narrators (`ilm Ar-rijaal).
- He must be well-versed with the Arabic language, the syntax, the science of rhetoric, the figure of speech and the ways of expression (turuq al-bayan).
- He must be well-acquainted with all other sources of Islamic law including ijma` (juristic consensus), qiyas (deduction) and istihsan (juristic preference).
Where To Practice Ijtihad?
As stated above, ijtihad is not open for anyone; rather, it is only open for the erudite scholars. Also, in the scope of ijtihad, not all topics and issues are subject to ijtihad, for the rule goes: "No ijtihad in the existence of a legal text."
Thus, the basics of Shari`ah that are well-defined in the Quran and the Sunnah of the Prophet, peace and blessings be upon him, are not subject to ijtihad. Therefore, there is no ijtihad to define the shares of inheritance since they are well explained in the Quran and there is no ijtihad to define the punishment for theft, adultery, high-way robbery (hirabah), since all these are explained in exactness in the Quran. Also, no one can practice ijtihad to say that hijab is not obligatory, since it has been declared mandatory in the Quran by the Lawgiver.
Also, there is no ijtihad in issues that are well-known and defined in Islam like the basics or in matters previously decided and unanimously agreed upon. No one can practice ijtihad in the issue of the Oneness of Allah or the number of daily prayers since this is already established.
One Final Point:
One more point, which needs to be highlighted is that a mujtahid is always rewarded so long as he practices ijtihad purely for Allah's sake.
In the hadith:
"If a ruler practices ijtihad and reaches a right decision, he will get double reward (i.e. one for his ijtihad and the other for his right decision.) And if he is to reach a wrong decision, he gets one reward only." (Reported in Sunnan Abu Dawud.)
Also, a mujtahid who practices ijtihad while being qualified and able to do it, then he is not subject to blame. When the Prophet, peace and blessings be upon him commanded his Companions to pray `Asr in the dwellings of Banu Qurayzah, some of them understood the hadith as a command to go there quickly and others got the exact wording of the hadith as a direct command. While the former prayed `Asr at their place and further proceeded to the dwellings of Banu Qurayzah, the latter waited till they reached the dwellings and prayed there. The Prophet, peace and blessings be upon him, did not reproach any of them since each group did their ijtihad.
In recent times, there are lots of voices, some asking for ijtihad to be abandoned, while others crying for its doors to be opened in front of everyone. Islam is not for any of these two groups; rather, it is for the moderates who go with the real guidance of Islam.
The Muslim nation is not void of mujtahideen at any time, for in each time there are lots of scholars and mujtahideen who are entrusted with preserving God's religion, defending His laws and offering solutions to people. A great name of a renowned mujtahid in the modern time is Sheikh Yusuf al-Qaradawi, may Allah bless his life and keep him safe! Amen!
I hope this answers your question and quenchs your thirst!
Thank you very much and please keep in touch!