The Marrakech scholar, speaking of the reign of Ali ibn Yusuf, said: "He neglected the study of the Book of God and the Hadith of the Messenger of God, so that none of the prominent scholars of that era paid much attention to them." As a result, the study of Usul al-Fiqh and the science of Ikhtilaf (disagreements) weakened in the Maghreb, and scholarly debate on the methods of deriving legal rulings, which formed the basis of Fiqh branches, almost ceased, unlike in the East. This was observed by Ibn Rushd when he said: "If a person today were to try on his own to ascertain all the arguments that scholars of different schools of thought have derived for the issues of disagreement, which have been debated among them in most of the Islamic lands except the Maghreb, he would be worthy of being laughed at." This is supported by what Abu al-Fadl ibn Muhammad al-Tuzri (d. 1119 AH / 1513 CE), the grammarian, narrated from al-Hasan al-Yusi (d. 1102 AH / 1690 CE), that when he entered Sijilmasa and began teaching Usul al-Fiqh, Abdullah ibn Bassam, one of the town's leaders, passed by him and asked: "What is this science he is teaching?" When he was informed, he said: "He wants to introduce us to sciences we do not know and to bring us innovations." Ibn Khaldun attributed the reason why the Malikis generally did not excel in the science of Ikhtilaf to the fact that "most of them are from the Maghreb, and they are nomadic and unaware of crafts, at least." This neglect of Usul al-Fiqh and Ikhtilaf led to the decline of Sharia thought. The Marrakech scholar, who was admired, is described by Ibn Khaldun as: "a noble science, of great benefit in knowing the sources and evidence of the Ummah, and it trains those who study it in argumentation and in what they seek to prove." Ibn Rushd, in Fasl al-Maqal, stated: "It is a noble science, of great benefit in knowing the sources and evidence of the Ummah, and it trains those who study it in argumentation and in what they seek to prove." Ahmad Mahmud Subhi, in the science of Kalam, and Al-Hasan ibn Mas'ud ibn Muhammad al-Marrakshi, a scholar and man of letters, participated in various sciences. He settled in Fez as a teacher. He also made a pilgrimage and studied in the East. Among his works are "Al-Muhadarat" and "Qanun Ahkam al-Ilm." Yusuf ibn Muhammad ibn Yusuf al-Tuzri, Abu al-Fadl, originally from Tuzar, was a scholar of Usul al-Fiqh who leaned towards reasoning and ijtihad. He studied under al-Lakhmi and al-Maziri and died in Qal'at Bani Hammad. He has the famous poem known as "Al-Munfarija." His biography can be found in Al-Timbukti's "Nail al-Ibtihaj." Al-Hasan al-Yusi, Al-Muhadarat. Ibn Khaldun, Al-Muqaddimah.