The istidlal bi'shadid alal-ghaib method in early Ash'ari theology

The most important tool for making judgments about God's essence and attributes in the early period of Islamic theology was the method of istidlal bi'sh-shahid ale'l-ghayb (reasoning from the witness to the unseen). In particular, the early Ash'ari theologians developed and systematized this method in a unique way within the framework of tawhid (the oneness of God) and tanzih (divine transcendence), and frequently used it to prove God's attributes. Unlike other schools, the early Ash'aris used this method in four different ways: through causality, conditions, evidence, and unity of truth, each time specifying conditions appropriate to their knowledge systems. Thus, they sought to create a comprehensive tool of reasoning that would encompass both existence and its Creator. However, the use of this method within the Ash'ari school was not uniform. Imam Ash'ari relied on the linguistic construct of taqifi (imposed) causality in his identification of causality and truth, while Bakillani and Imam Juwayni derived their approach from theories of states. In particular, Imam Juwayni's critiques of theological methodology during his second period had a direct impact on the subsequent use of this method.