أسّس الشافعيُّ علمَ أصولِ الفقهِ، وقد تلقّاهُ العلماءُ والفقهاءُ الذين جاؤوا بعدَهُ بالقبولِ، فدرسوهُ وبحثوهُ، فزادوا فيهِ وهذّبوا كثيراً من مسائلِهِ، حتّى صارَ علماً مُتّسقاً واضحاً متميّزاً في خصائصِهِ، وذلكَ بفضلِ الأساسِ المتينِ الذي أرساهُ الإمامُ الشافعيُّ لهذا العلمِ الجليلِ.

Ash-Shaafi’iy founded the ‘Ilm of Usool ul-Fiqh and this was received (well) by the ‘Ulamaa and Fuqahaa, who followed him, through examination and study. So they added to it and revised a number of issues within it until it became an ‘Ilm that was coherent, clear and distinguished in its features, due to the firm foundation that Al-Imaam Ash-Shaafi’iy laid down solidly for this noble knowledge.

لم يبلغ الشافعيّ بأصول الفقه مبلغ الكمال، فجاء آخرون ليُتمّوا البناء الذي بدأه. فكان من بينهم من تبعه مُفصِّلًا ومُوضِّحًا، ومنهم من جاء مضيفًا قواعد جديدة، ومنهم من جاء ناقدًا ومخالفًا له في بعض القواعد.

Ash-Shaafi’iy did not reach the point of completion in respect to Usool ul-Fiqh and so others came to complete the building that he had begun. There were from amongst them those who followed him providing explanation and elaboration, there were also those who came adding new principles whilst others came critiquing and disagreeing with him in respect to some of the Qawaa’id (principles).