On the relations between logic and religion in the Islamic world, one may refer to logic in two different ways: 1. logic in religious texts, that includes doctrinal sacred texts such as Qur’ān and sayings of the Prophet (as well as Imāms, in Shī’īism), as well as the Qur’ānic commentaries and the texts related to the principles and fundamentals of jurisprudence, all of which make use of some reasoning to persuade the audience or to infer the rules and prescripts for the religious behavior of members of the religious community; and 2. logic as a discipline that is studied and applied both independently and as a tool for reasoning in (a) schools of Islamic theology (from Ash’aris to Mu’tazilis and Shī’īs), (b) systems of Islamic philosophy (from Peripatetics to Illuminationists), and (c) other types of knowledge in the medieval Islamic world, all being strongly influenced by religious doctrines of Islam.