Al-Shofiiy usul ilmini asoslashga muvaffaq bo‘lishiga yordam bergan narsa, u fiqh ilmi ancha rivojlangan bir davrda yashagani bo‘ldi. Islom yerlarida mujtahidlarning huquqshunoslik guruhlari shakllana boshladi va ular mazhablarga birlasha boshladi. Mujtahidlar bilan mazhab tarafdorlari o‘rtasidagi munozara fiqh va dalillarda turli qarashlarni o‘z ichiga oldi. Shu sababli u munozaraga kirishganlar bilan bahslashishga kirishdi, bu muhokamalar uni o‘rganish va xulosa chiqarish asosi bo‘lishi kerak bo‘lgan umumiy va keng qamrovli tamoyillarni tartibga soluvchi mezonlar sifatida o‘ylashga yo‘naltirdi. U bu tamoyillarni usul al-fiqh ilmi sifatida yagona bilim majmuasiga jamladi.
Al-Shofiiyning usulidagi diqqatga sazovor jihat shundaki, u usulni muhokama qilishda mantiqiy emas, balki qonunchilik yo‘nalishida yuradi. Tadqiqot uchun, aslida esa ummatning, xususan fiqh va usulda tiklanishi uchun eng katta xavflardan biri mantiq yo‘lidir. Al-Shofiiy mantiq yo‘lidan aniq uzoqlashib, qonunchilik yo‘nalishiga amal qildi. U nazariy usullar yoki taxminlarga qiziqmadi. U haqiqiy va mavjud masalalarni tartibga solishni xohladi, ya’ni Shariat matnlarini olib, matnning chegarasida va matn ko‘rsatgan hamda odamlarning o‘zlari guvohi bo‘lgan haqiqat chegarasida to‘xtadi.
Nasx masalasiga (nosix va mansux) kelganda, u o‘z nazarida nasx mavjudligi isbotlangan masalalardan nasx tamoyillarini belgiladi. Bu tamoyillar oyat yoki hadisning o‘zida zikr etilganidan, nasxning dalolatidan yoki Payg‘ambarga nisbatan rivoyat qilingan nasxni ko‘rsatuvchi hadislardan, yoxud Allohning Rasulining sahobalari haqida xabar va hukmlar sifatida naql qilinganlaridan olingan. Boshqalar, uning ortidan kelganlardan farqli o‘laroq, ikki oyat yoki hadis o‘rtasida ziddiyat ko‘rganda, darhol birining ikkinchisini bekor qilganini (nasx) aytishga shoshilmagan, natijada dahshatli xatolarga yo‘l qo‘yganlar. Ash-Shofi‘iy bir qoidani olib kelganda, uni mantiqiy muqaddimadan (muqaddima mantiqiyya) olmagan, balki qaysi manbadan olganini ko‘rsatgan: ya’ni Payg‘ambar ﷺ dan rivoyat qilingan xabardan yoki sahobalarning fatvolaridan.
Umumiy qoidalarni (qawa’id dabita) keltirib chiqarishdagi uslubi amaliy bo‘lib, u voqelikka, dalillarga va bu narsalarni aniq holatlarga qo‘llashga tayangan. Shofi‘iylar usulining eng ko‘zga ko‘rinadigan jihati shundaki, u hukmlarni istinbot qilish uchun umumiy qoidalarni o‘z ichiga oladi, uning aniq uslubi qanday bo‘lishidan qat’i nazar. Aksincha, uning usuli har qanday, qanchalik farq qilmasin, uslubga mos keladi. Shu sababli u fikrlarning qaysi biri to‘g‘ri, qaysi biri noto‘g‘ri ekanini bilish uchun mezon bo‘lib xizmat qiladi. Kishi o‘zi qanday uslubni tanlashidan qat’i nazar, yangi hukmlarni chiqarganda, fikrlarni baholash va hukmlarni keltirib chiqarishni umumiy qonun asosida tartibga solish uchun rioya qilinishi shart bo‘lgan keng qamrovli qonundir.
Ash-Shofi‘iyning usuli faqat uning mazhabi uchun usul bo‘lishi niyat qilinmagan, garchi mazhab unga amal qilgan bo‘lsa-da. U o‘z mazhabini himoya qilish va uning qarashini izohlash uchun yozilmagan. Aksincha, u istinbot uchun umumiy va keng qamrovli qoidalarni o‘z ichiga oladi. Sababi biror muayyan mazhabga moyillik emas, balki ijtihod tartibini tartibga solish, mujtahidlar uchun chegaralar va yo‘riqnomalar o‘rnatish istagi edi. U niyatida xolis edi va usul al-fiqh ilmini yaratishda to‘g‘ri tushunchaga ega edi; shu tufayli u Ash-Shofi‘iydan keyin kelgan mujtahidlar va ulamolarning barchasiga, ularning fikrlarini qo‘llab-quvvatlagan yoki qarshi chiqqanidan qat’i nazar, istisnosiz ta’sir ko‘rsatdi. Shunga qaramay, turli yo‘nalishlariga ko‘ra, ular al-Shofi‘iy yo‘lidan borayotganini ko‘rdilar: kulliy qoidalarni belgilash (qawa’id kulliyya) va fiqh hamda istinbot (xulosa chiqarish) ishini umumiy qonunlar va umumiy qoidalar asosida tartibli ravishda olib borish jihatidan. Undan keyingi fiqh, oldingi davrdagidek fatvolar va alohida hukmlar (aqdiya) to‘plami sifatida emas, balki mustahkam asoslarga tayangan holda shakllandi.
Barcha ulamo usul al-fiqh tushunchasi jihatidan al-Shofi‘iy izidan borgan bo‘lsalar-da, ular al-Shofi‘iy erishgan natijalarni o‘zlarining turli huquqiy yondashuvlariga ko‘ra turlicha qabul qildilar. Ba’zilari uning fikrlariga ergashib, ularni sharhlash va kengaytirishga kirishdilar, hatto ulardan ixtilof qildilar, xuddi al-Shofi‘iyning o‘zi tarafdorlari kabi. Ba’zilari esa usulning ayrim tafsilotlarida ixtilof qilsalar-da, al-Shofi‘iy keltirgan asosiy qismni oldilar, lekin usulning o‘zagini emas. Ular usulning tuzilmasi, asosi va yo‘nalishida ixtilof qilmaganliklari sababli, masalan, hanafiylar va ularning usulini tutganlar shunday bo‘ldilar. Shuningdek, bu usulda al-Shofi‘iyga qarshi chiqqanlar ham bor edi, masalan, zohiriylar va shialar. Al-Shofi‘iyning fikrlariga ergashganlar hanbaliylar edi. Ular, garchi yagona (tan olingan) ijmo‘ sahobalarning ijmo‘i deb hisoblagan bo‘lsalar-da, al-Shofi‘iyning usulini qabul qildilar. Al-Shofi‘iydan keyin kelgan molikiylar o‘z metodologiyasini al-Shofi‘iy usulidagi ko‘p narsalar bilan uyg‘unlashtirdilar, garchi Madina aholisining amaliyotini dalil deb bilsalar-da va ayrim tafsilotlarda unga zid bo‘lsalar-da. Uning usulidan yo‘l tutib, fikrlarini qabul qilganlar esa uning mazhabidagi kishilar bo‘lib, usul al-fiqh ilmi bilan juda faol shug‘ullanganlar va bu mavzuda ko‘plab asarlar yozganlar. Al-Shofiy usuli bo'yicha usul al-fiqh ilmidagi kitoblar yozildi, ular bu ilmning ustunlari va tayanchi bo'lib kelgan va hozir ham shundaydir. Qadimgi olimlar tomonidan yozilgan, ma'lum bo'lgan eng muhim uchta kitob bor: birinchisi, Abu al-Husayn Muhammad ibn al-Basriyning (vafoti 413 hijriy) "al-Mu'tamad" kitobi; ikkinchisi, "Imom al-Haramayn" nomi bilan mashhur bo'lgan Abd al-Malik ibn Abdulloh al-Juvayniyning (vafoti 478 hijriy) "al-Burhon" kitobi; uchinchisi, Abu Hamid al-G'azzoliyning (vafoti 505 hijriy) "al-Mustasfo" kitobi. Ulardan keyin Abu al-Husayn Ali, unga al-Omidiy nomi bilan ham tanilgan, keldi. U bu uch kitobni birlashtirib, ularni "al-Ihkom fi usul al-ahkom" kitobida kengaytirdi, bu kitob usul al-fiqh bo'yicha yozilgan eng muhim asarlardan biri bo'ldi.
Al-Shofiy keltirgan narsalarning asosiy qismini qabul qilib, ayrim tafsilotlarda unga xilof qilganlar esa hanafiylardir. Chunki ularning istinbot (xulosa chiqarish) usuli al-Shofiyning usullariga mos keladi, garchi usul ilmiga yondashuvlari furu' (fiqhning tarmoqlari) ta'siri ostida bo'lgan. Ular usul qoidalarini furu'ni qo'llab-quvvatlash maqsadida o'rganganlar. Shu sababli furu'ni asos qilib olganlar, umumiy qoidalar esa unga tayanib, uni qo'llab-quvvatlash uchun shakllantirilgan. Ehtimol, ularni bunday yondashuvga undagan narsa, usul ilmini o'rganishlari o'z mazhablarini qo'llab-quvvatlash maqsadida bo'lgan, mazhablari hukmlar chiqariladigan qoidalarni ishlab chiqish uchun emas edi. Chunki al-Shofiydan oldin o'tgan Abu Hanifa al-Shofiy tug'ilgan yili vafot etgan, uning xulosalari esa umumiy va keng qamrovli qoidalarga asoslanmagan. Shuningdek, undan keyin uning shogirdlari Abu Yusuf, Muhammad va Zufar keldilar. Ular usul al-fiqh haqida yozish bilan shug'ullanmadilar, lekin keyinchalik hanafiy mazhabi olimlari hanafiy mazhabi furu'iga xizmat qiladigan qoidalarni izlashni o'z zimmalariga oldilar. Qoidalar furu'dan keyin paydo bo'lgan va uni oldin o'tmagan. Shunga qaramay, hanafiy usul umuman olganda shofe'iy usuliga asoslangan. Ular shofe'iylar bilan farq qilgan masalalarga kelsak, ya'ni 'omm (umumiy) hukmning xos (aniq) kabi qat'iy bo'lishi masalasida ...
What helped al-Shafi’i to lay down the science of usul was that he came at a time when Islamic jurisprudence had started to greatly flourish. In the Islamic lands juristical groups of mujtahidin began to take shape and they began to form into mazhabs (schools). The debate between the Mujtahidin and the proponents of mazahibs took various perspectives in fiqh and the evidences. So he plunged into debates with those who engaged in the debate, these discussions were what guided him to think about general and comprehensive principles as regulatory criterions which should be the basis of study and inference. He brought together these principles as one body of knowledge which was the science of usul al-fiqh. The impressive thing about the usul of al-Shafi’i is that he proceeds in the discussion of usul in a legislative and not in a logical manner. One of the greatest dangers for study, in fact for the Ummah’s revival especially in fiqh and usul is the path of logic. Al-Shafi’i clearly distanced himself from the course of logic and adhered to the legislative course. He was not interested in theoretical methods or suppositions. He wanted to regulate real and existing issues i.e, he took the Sharī’ah texts and stopped at the limit of the text and at the limit of the reality which the text indicated and the people themselves witnessed. Regarding the issue of abrogation (nasikh wal mansukh), he established the principles of abrogation from the issues which, for him, had been proven to contain abrogations, taken from what has been mentioned in the ayah or hadīth itself, or from the indication (dalala) of abrogation, or what has been narrated about the Messenger in terms of hadīth which indicate abrogation or whatever has been reported about the Companions of the Messenger of Allah in terms of reports and judgements. Not like many who came after him when they saw a contradiction between two verses or ahadīth they immediately moved to say that one has abrogated the other, to the extent that they ended up making terrible blunders. When al-Shafi’i came with a principle he did not bring it from a logical premise (muqaddima mantiqiyya) rather he showed the sources from which he took it, either from a report about the Prophet or from legal verdicts (fatwas) of the Sahabah. His approach in deriving regulatory (qawa’d dabita) principles was a practical one in which he relied on the reality, the evidences, and on the application of those things on tangible facts. The most prominent aspect by which Shafi’is usul is distinguished is that it contains general principles for the deduction (istinbat) of rules, regardless of what his specific methodology was. Rather, his usul is suitable for any methodology however different it may be. Thus, it is a measure by which one can know which opinions are correct and which are not correct. It is a comprehensive law which must be adhered to when deducing new rules, whatever methodology a person may set himself, in order to judge opinions and regulate the inference of rules by a comprehensive law. The usul of al-Shafi’i was not intended to be an usul for his mazhab (school) only, even though the mazhab adhered to it. It was not written to defend his mazhab and clarify its viewpoint. Rather, it contains general and comprehensive principles for istinbat (inference). The motive was not a trend towards a particular mazhab but rather it was a desire to regulate the procedures of Ijtihād and put in place limits and guidelines for the mujtahidin. He was sincere in his intentions and he had the correct understanding when devising the science of usul al-fiqh, thereby influencing, without exception, those mujtahidin and ‘Ulamā that came after al-Shafi’i, whether they opposed or supported his opinions. Until, despite their different tendencies, they saw themselves proceeding according to the path al-Shafi’i had taken, in terms of setting out comprehensive principles (qawa’id kulliyya) and proceeding in fiqh and istinbat (inference) in a regulated manner according to comprehensive laws and general principles. Fiqh (Islamic jurisprudence) after him came to be based on established foundations not as an assortment of fatwas and individual judgements (aqdiya) as was the case before him. Even though all of the ‘Ulamā proceed in the footsteps of al-Shafi’i in terms of the notion of usul al-fiqh, however the way in which they received what al-Shafi’ had arrived at was different according to their different juristic approaches. Some followed his opinions and began to explain and expand on them and disagree with them, like the followers of al-Shafi’i himself. And some took the major part of what al-Shafi’i had brought despite their disagreement with certain details of usul and but not the actual body of usul. Since they had no disagreements in terms of the body, framework and course of al-Shafi’is usul, like the Hanafis and those who followed their method. And there were those who disagreed with al-Shafi’i in this usul, like the Zahiris and Shi’a. Those who followed al-Shafi’i in his opinions were the Hanbalis. They adopted the usul of al-Shafi’i even though they said the only (recognised) ijma’ (consensus) is that of the Sahabah. The Malikis who came after al-Shafi’i combined their methodology with much of what was in al-Shafi’i’s usul though they took the practise of the people of Madina as a proof and differed with him in certain details. As for those who proceeded according to his method and embraced his opinions they are the followers of his mazhab who were very active in the (study of) the science of usul al-fiqh and wrote prolifically about the subject. Books were written according to the methodology of al-Shafi’i in usul al-fiqh which were, and still are, the pillars and support of this science. Of the most important three books that are known to be written by the ancients: First, the book al-Mu’tamad of Abu al Husayn Muhammad ibn al-Basri (d.413 A.H.), Second, the book al-Burhan of ‘Abd al-Malik ibn’ Abd Allah al-Juwayni commonly known as imam al-Harāmayn (d.478 A.H.) and third, the book al-Mustasfa of Abu Hamid al-Ghazali (d.505 A.H). After them came Abu al-Husayn ‘Ali otherwise known as al-Amidi. He brought together all three books and expanded on them in his book al-ihkam fi usul al-ahkām, which was one of the most important works written on usul al-fiqh, as for those who adopted the major part of what al-Shafi’i brought and differed in some of the details, they are the Hanafis. That is because their method of istinbat (inference) agreed with the usul of al-Shafi’i though the way in which they approached the science of usul was influenced by the furu’ (branches of fiqh). They studied the principles of usul in order to support the furu’. So they made the furu’ the basis. The general principles were based on it and made to support it. Perhaps what pushed them towards this approach was that their study of usul was for the purpose of supporting their mazhab and not in order to produce principles according to which their school should deduce rules. That is because Abu Hanifa who had preceded al-Shafi’i, died the year in which al-Shafi’i was born. And his inferences were not according to general and comprehensive principles. Likewise after him came his students Abu Yusuf, Muhammad and Zufar. They did not concern themselves with writing about usul al-fiqh but it fell to the scholars of the Hanafi mazhab afterwards to pursue the inference of principles which would serve the furu’ of the Hanafi mazhab, The principles came later than the furu’ and did not precede it. Nevertheless, the Hanafi usul on the whole has been extracted from the usul of al-Shafi’i. And what they differed on with the Shafi’is in terms of the ‘aamm (general) being qat’i (definite) like the khas (specific),