ʿIlmu ʾl-Kalām is the discussion of all subjects connected with the six articles of the Muslim Creed: 1, the Unity of God; 2, the Angels; 3, the Books; 4, the Prophets; 5, the Day of Judgment; 6, the Decrees of God, as distinguished from al-Fiqh, which is an exposition of the five foundations of practical religion—1, recital of the Creed; 2, prayer; 3, fasting; 4, zakāt; 5, ḥajj.
The most celebrated works on the subject of ʿAqāʾid or ʿIlmu ʾl-Kalām are: Sharḥu ʾl-ʿAqāʾid, by the Maulawī Masʿūd Saʿdu ʾd-dīn at-Taftāzānī, A.H. 792; the Sharḥu ʾl-Muwāqif, by Saiyid Sharīf Jurjāni.
ʿILMU ʾL-LUG͟HAH (عـلـم اللغة). Lexicography. [[ARABIC LEXICONS].]
ʿILMU ʾL-MANT̤IQ (عـلـم المنطق). Logical science. [[LOGIC].]
ʿILMU ʾL-MASĀḤAH (علم المساحة). Mensuration.
ʿILMU ʾL-MILĀḤAH (عـلـم الـمـلاحة). The nautical art. The science of making and navigating ships.
ʿILMU ʾL-MŪSĪQĪ (علم الموسيقى). The science of Music. [[MUSIC].]
ʿILMU ʾL-UṢŪL (علم الاصول). The science of the “roots,” or fundamentals of the religion of Muḥammad, namely, of the Qurʾān, Aḥādīs̤, Ijmāʿ, and Qiyās. The science of exegesis, or the rules of interpretation of these four roots of Islām. An explanation of the methods of this science will be found in the article on [QURʾAN], Sect. viii., the same principles applying to the other three fundamentals.
The best known works on the ʿIlmu ʾl-Uṣūl are the Manār, by ʿAbdu ʾllāh ibn Aḥmad an-Nasafī, A.H. 710, and its commentary, the Nūru ʾl-Anwār; also at-Tanqīḥ, by ʿUbaidu ʾllāh ibn Masʿūd, A.H. 747, with its commentary, at-Tauẓiḥ, by the same author, and a super-commentary, the Talwīḥu ʾt-Tauẓīḥ, by Saʿdu ʾd-dīn Masʿūd ibn ʿUmar at-Taftāzānī, A.H. 792.
AL-ʿILMU ʾL-YAQĪN (العلم اليقين). Certain knowledge; demonstration; a religious life; a knowledge of the truth.