The Revolution which made the fortune of the ‘Abbásid House was a triumph for Islam and the party of religious reform. While under the worldly Umayyads the studies of Law and Tradition met with no public encouragement and were only kept alive by the pious zeal of oppressed theologians, the new dynasty drew its strength from the Muḥammadan ideas which it professed to establish, and skilfully adapted its policy to satisfying the ever-increasing claims of the Church. Accordingly the Moslem sciences which arose at this time proceeded in the first instance from the Koran and the Ḥadíth. The sacred books offered many difficulties both to provincial Arabs and especially to Persians and other Moslems of foreign extraction. For their right understanding a knowledge of Arabic grammar and philology was essential, and this involved the study of the ancient Pre-islamic poems which supplied the most authentic models of Arabian speech in its original purity. The study of these poems entailed researches into genealogy and history, which in the course of time became independent branches of learning. Similarly the science of Tradition was systematically developed in order to provide Moslems with practical rules for the conduct of life in every conceivable particular, and various schools of Law sprang into existence. [Sidenote: Their classification.] Muḥammadan writers usually distinguish the sciences which are connected with the Koran and those which the Arabs learned from foreign peoples. In the former class they include the Traditional or Religious Sciences (_al-‘Ulúm al-Naqliyya awi ’l-Shar‘iyya_) and the Linguistic Sciences (_‘Ulúmu ’l-Lisáni ’l-‘Arabí_); in the latter the Intellectual or Philosophical Sciences (_al-‘Ulúm al-‘Aqliyya awi ’l-Ḥikmiyya_), which are sometimes called 'The Sciences of the Foreigners' (_‘Ulúmu ’l-‘Ajam_) or 'The Ancient Sciences' (_al-‘Ulúm al-Qadíma_). The general scope of this division may be illustrated by the following table:-- I. THE NATIVE SCIENCES. 1. Koranic Exegesis (_‘Ilmu ’l-Tafsír_). 2. Koranic Criticism (_‘Ilmu ’l-Qirá’át_). 3. The Science of Apostolic Tradition (_‘Ilmu ’l-Ḥadíth_). 4. Jurisprudence (_Fiqh_). 5. Scholastic Theology (_‘Ilmu ’l-Kalám_). 6. Grammar (_Naḥw_). 7. Lexicography (_Lugha_). 8. Rhetoric (_Bayán_). 9. Literature (_Adab_). II. THE FOREIGN SCIENCES. 1. Philosophy (_Falsafa_).[514] 2. Geometry (_Handasa_).[515] 3. Astronomy (_‘Ilmu ’l-Nujúm_). 4. Music (_Músíqí_). 5. Medicine (_Ṭibb_). 6. Magic and Alchemy (_al-Siḥr wa-’l-Kímiyá_). [Sidenote: The early ‘Abbásid period favourable to free-thought.]