[The prophets] bring both what reason cannot deny and would not be guided to independently; provisions of the Law, the Divine promises and threats, on which depend judgments and which reason would not perceive, even though it concurs with all virtuous things. But reason would not concur on all the particulars which the Laws expound. Thus there is no obstacle in what the prophets bring to what reason makes clear, so that they confirm the data of reason and assist it. [Besides] when one speaks according to the propositions of reason, his words may not be counted as nonsense, even if reason has led to what he is saying. There are to be sure in some of the things God has created satisfying proofs as to the existence of the Creator, and none of the wonders of creation may be counted an absurd thing.
— from “Al-’Aquida al-Nizamiya”
Imam al-Haramayn Dhia’ ul-Din Abd al-Malik ibn Yusuf al-Juwayni al-Shafi’i (1028–1085) was an important Sunni imam and Muslim scholar. Born in Iran into a family of noted lawyers and legal scholars, al-Juwayni was especially gifted in matters of jurisprudence. Noted for his opinions on the moral life, al-Juwayni was opposed to all legal speculation and based his moral philosophy squarely on the Koran and Hadith, the extra-Koranic sayings and acts of the prophet Mohammad.