Who?

Alkindi (801-873). Abu Yusef Yaquib ibn Ishaq al-Sabbah al-Kindi. The "philosopher of the Arabs"; helped make philosophy part of Islamic culture. Argued for compatibility of philosophy with religious faith; distinguished two by their dependence on reason or revelation. In his treatise "On the Intellect," he presented Aristotle’s agent intellect ("the intellect always in act") as an "Intelligence"—a spiritual being or substance separate from each human intellect, and common for all men.

Alfarabi (870-950). Abu al-Nasr al-Farabi. Made key distinction between God and creatures: God is necessary, a creature is possible in terms of itself, necessary in terms of God. So creatures are not necessarily bound to existence—Alfarabi is the author of the distinction between essence and existence, in its metaphysical sense.

Avicenna (980-1037). Abu Ali al-Husain ibn Abdallah ibn Sina. Philosopher, metaphysician, doctor. Diminished the Koran to metaphorical language. Developed Alfarabi’s metaphysical distinction being essence and existence. Essence (not Being as in Erigena) is a limiting idea—God is a being (an actuality), but God has no essence. God is existence itself. Essences in themselves are simple, and can exist in several ways: in the real world, as single individuals; in the intellect as universals. Human knowledge is a form of illumination by the Agent Intellect (=the angel Gabriel).

Algazal (1058-1128). Abu Hamid ibn Muhammmad al-Tusi al-Shafi’i al-Ghazali. Theologian and philosopher. Criticized the rationalism of the philosophers, especially Alfarabi, arguing for the inability of reason to comprehend God. (Is Avicenna guilty too?) So he defended the primacy of faith over reason. Defended creation of the world in time, argued for an occasionalism—God’s universal causality.

Averroes (1126-1198). Abul Waleed Muhammad ibn Rushd. The Great Commentator because of his esteemed commentaries on Aristotle. Referred to as "that accursed Averroes" by Duns Scotus. Accused of a tendency to identify philosophy with Aristotle, and had little conception of philosophical progress. Defended Aristotle against (1) philosophers like Alfaraba and Avicenna, who he thought had distorted Aristotelian philosophy by mingling it with religious doctrines; and (2) Moslem theologians who attacked philosophy as an enemy of religion (Algazeli). Denied creation of the universe. Denied the metaphysical distinction between essence and existence. Argued against the immortality of individual human beings.