Shias have a system of Ijtihad when a person is qualified after a meticulous and exhaustive study to issue a Fatwa on certain jurisprudential issues. These persons are mostly alive and they can issue Fatwas on prevalent or current issues which were not present few (hundred) years ago. While I see Sunnis believe on just four such Imams (Malik, Ahmad bin Hanbal, Abu Hanifa, Shafie). I wonder what do Sunnis do when they are confronted with everyday issues. Do they search and research themselves from books of Hadith which is not correct. They do refer to local or prominent religious scholar. But I want to ask if there is any standard which a person must have before he can answer people's question? If there is a standard or a system then what is this?
The Sunni school alternative to the Shi'as' ijithād is also called ijtihād (independent reasoning), and it may be done by scholars who are alive or may have been done by scholars over the centuries (the four Imams included, but not limited to them).
The basic rule of ijtihād in the Sunni view is when a matter has its core in agreement with another, then the ruling that applies to one of its branches applies to the other branch provided that the 'illah is the same. For example, wine (first core) is prohibited (ruling) because it is an intoxicant ('illah). Japanese saké (second core) intoxicates (shares the same 'illah); therefore, Japanese saké is also prohibited (shares the same ruling).
The differences that you may have heard of between Sunnis and Shias is that Sunnis in regards to terminology of jurisprudence use exclusively the descriptive term (Arabic: تعريف الاجتهاد في الاصطلاح باعتبار معناه الوصفي), whereas Shias lately have attempted to use descriptive as well as taxonomical term (Arabic: تعريف الاجتهاد في الاصطلاح باعتبار معناه الاسمي) . This is from the science of fundamentals of jurisprudence (Arabic: علم الأصول) aspect. Imam Ash-Shātibi discussed this in his book Al-Muwāfaqāt, Vol. 6, pp. 51 in particular (and the entire chapter he had on the topic pp. 7-340 of the same volume, where he covers the topic at length). Based on this definition, defining who is qualified to do ijtihād comes next. There are two opinions:
- Those who have specific Islamic jurisprudence qualifications, which is the opinion of Al-Baramāwi, At-Taftazāni, Ibn Al-Hājib, Ibn Al-Humām, Ibn An-Najjār, Ibn As-Subki, Ibn Muflih, among others.
- Those who have knowledge (need not be constrained to Islamic jurisprudence), which is the opinion of Ar-Rāzi, As-Safi Al-Hindi, Ash-Shātibi, At-Tabrīzi, Az-Zarkashi, Ibn Juzai, Ibn Qudāmah, among others.
The second opinion allows the inclusion of subject matter experts (e.g., doctors on organ transplants, bankers and economists on the trade of stock options, etc.) in the committee that would do ijtihād.
In both the Sunni and Shia sects, the jurists have their own grades (Arabic: طبقات العلماء). You may refer to, for instance, the following references (Arabic only) on the Sunni perspective (and general discussions of ijithād):
- Al-Qawl al-Mufīd fi Adellat al-Ijtihād wa at-Taqlīd by Ash-Shawkāni
- Irshād an-Nuqqād ila Taisīr al-Ijtihād by As-San'āni
- Tabaqāt al-Fuqahā' by Ash-Shirāzi
- Tabaqāt ash-Shāfi'iyyah al-Kubra bu As-Subki