Am I obliged to follow only one of the four sunni legal schools of jurisprudence? Are there any other options that one can follow?
Regarding this issue, there is a difference between learning and applying. When it comes to applying, abiding by a certain legal school of jurisprudence for lay people is not obligatory in every matter as they are eligible to adopt the legal opinion of other juristic scholars and mujtahids. Therefore, lay people have no certain legal school of jurisprudence because they follow the juristic opinion of the scholar they ask.
This is the established opinion for the Hanafis. The renowned Hanafi scholar Ibn ‘Abdeen stated in his commentary in reference to Imam al Sharnibali that he said, “one does not have to abide by a certain legal school and he is permitted to follow an opinion which opposes the opinion of the juristic legal school which he follows. He is allowed to adopt two opposite opinions in two separate incidents that are not related to each other. He is not permitted to nullify an action he did by the virtue of following the juristic opinion of another scholar because engaging in an action is similar to passing a verdict by a judge with no appeal.
This opinion is supported with God as He asserted the obligation of following scholars in general with no specification or dedication to one scholar over the other. God says in the Quran, “So ask the people of knowledge if you do not know” 16:43. Also when people posed their questions at the time of the Prophet’s companions and the scholars of the next generation, they did not abide by a certain school but they rather asked eligible scholars without limiting themselves with the opinion of someone while denying the opinion of the other.
Following one of the opinions of the mujtahids (eligible scholars who practice independent legal reasoning) is in fact following the truth. All the mujtahid scholars are correct and this means that each of them follows his own independent legal reasoning which led him to believe in the validity of the concluded ruling. As one chooses to follow any of the scholarly opinions of these renowned mujtahids, he/she should not believe that this is the only correct juristic opinions and other opinions are invalid.
As for the issue of learning and studying different legal schools of jurisprudence, following a certain school of jurisprudence is inevitable. The four Sunni legal schools of jurisprudence were well served and deeply studied by generations of renowned scholars in a way that other schools of jurisprudence were not subjected to. The four schools were well edited and the popular and favored opinions were highlighted and backed with authentic supporting evidence. The biographies of the renowned scholars of each school were documented and their methodologies of deriving juristic legal rulings were scrutinized so each of them became an independent school of jurisprudence that benefits those who seek religious knowledge.