As mentioned in the previous installment, Avicenna is famous for making a distinction between essence (“what it is”) and existence (“that it is”) regarding contingent beings. Given that at the same time as he was attempting to correlate Muslim doctrine with Aristotelian ideas he was also following a Neoplatonic emanationist scheme of being, Avicenna posited that the One (the Necessary Being, God) could not help but create things other than Himself.:”(The following summary of Avicenna is a synthesis of materials found in several sources, including John Marenbon, Medieval Philosophy: An Historical and Philosophical Introduction [London and New York: Routledge, 2007], pp. 17-19 [on Plotinus] and 103-111 [on Avicenna]; David B. Burrell, “Avicenna,” in A Companion to Philosophy in the Middle Ages, eds. J.E. Gracia and Timothy B. Noone [Blackwell Publishing, Ltd., 2003], pp. 196-208; Jean Jolivet, “From the Beginnings to Avicenna,” in Routledge History of Philosophy Vol. III: Medieval Philosophy, ed. John Marenbon [London and New York: Routledge, 1998], pp.29-48; and Stephen Dumon, “Henry of Ghent and Duns Scotus,” in ibid., pp. 299-328.)”: Interestingly, this conclusion could be drawn from both philosophical trajectories. For Plotinus’ Neoplatonism, the One (the Necessary Being, God) necessarily overflows and diffuses into lower “levels” of being. For Aristotle, the Unmoved Mover necessarily causes all other motion in the world “precisely by being that One that all things desire.”:”(Burrell, op. cit., pg. 199.)”:
Avicenna accepts Aristotle’s description of the Unmoved Mover as “pure Act with no Potentiality.” What this means is that the Unmoved Mover / Necessary Being / God has no possibilities within Him that are not fully realized, for if He did, there would be imperfection and impermanence within Him and He could not therefore be the perfect source and ground of all other beings:
[The Necessary Being] is free from all kinds of defect; its existence is therefore complete. Consequently its existence is the most complete existence, free from causes such as matter, form, act and end, and it has no quiddity other than that it is necessary of existence; this is its individual nature…Its existence by itself is without end or beginning, no privation is mixed with it, and its existence is not potential. Consequently it is not possible that it would not exist, it has no need of anything to provide its permanence, and it does not change from one state to another. It is one, in the sense that the reality that it has does not belong to any other thing.:”(Cited in Basic Issues in Medieval Philosophy, Second Edition, eds. Richard N. Bosley and Martin M. Tweedale [Broadview Press, 2006], pg. 13.)”:
This leads Avicenna to the distinction (mentioned several times already) between essence (“what it is”) and existence (“that it is”) regarding contingent beings. The distinction forms an integral part of his rational demonstration of the Necessary Being, for it explains the critical difference between the Necessary Being and all beings other than Itself (which it necessarily creates). The Necessary Being’s existence is its essence – there is no distinction, because the Necessary Being cannot not exist but exists necessarily. Things other than itself, however, things which It creates, are contingent upon It – their essence and existence are distinct because it is possible for them not to exist. The essence of contingent beings is “possible in themselves,” but their existence comes to them from the One / Necessary Being / God.
This move successfully adapts Aristotle to the Koran by denying that the world is eternally existent – an assumption which Aristotle had simply made, not defended. Instead, for Avicenna the world is a contingent being deriving its existence from God. But the adaptation would fail to be completely to the liking of orthodox Islam. Thanks to his Neoplatonic emanationist influences, although Avicenna thought of the contingent beings as only being “possible in themselves” at the same time he thought of them as being necessarily created by the Necessary Being. The Koran portrays God as being free to create or not create, but Avicenna has Him necessarily creating:”(Burrell, op. cit., pp. 199-200.)”:
A later Muslim philosopher, Al-Ghazali, will vigorously attack this necessitarian view of God and defend God’s absolute freedom to do things other than what He actually does. As well, Medieval Christian Scholastics will take up Avicenna’s essence-existence distinction and modify it further in order to preserve the biblical God’s freedom to create or not create. Thomas Aquinas will use the Avicennian distinction to highlight and defend the Christian distinction between Creator and creature and to preserve, contra Avicenna (!), the biblical idea that God is free to create or not create.:”(Ibid., 206.)”: Henry of Ghent will build on and modify Avicenna’s distinction as part of his own attempt to maintain God’s freedom to create – as well as the creation of the world in time.:”(R. Wielockx, “Henry of Ghent,” in A Companion to Philosophy in the Middle Ages, pp. 296-304; Frederick Copleston, S.J., A History of Philosophy Vol. II: Medieval Philosophy [New York: Doubleday, 1993], pp. 465-475.)”:
Clearly, then, Avicenna has enormous importance for an understanding of the philosophical conversations of Medieval Christendom.