GOD if it contained only contingent causes it would need an external cause and thus not be complete To show that a being necessarily existent of itself is God, Avicenna has to prove that such a being (which he henceforth calls, for short, ‘necessary being’) must possess the deWning attributes of divinity In the seventh section of the Wrst tractate of his Metaphysics Avicenna argues that there can be at most one necessary being; in the eighth tractate he develops the other attributes of the unique necessary being It is perfect, it is pure goodness, it is truth, it is pure intelligence; it is the source of everything else’s beauty and splendour (Metaph 368) The most important feature of the necessary being is that it does not have an essence which is other than its existence.6 If it did, there would have to be a cause to unite the essence with the existence, and the necessary being would be not necessary but caused Since it has no essence other than its existence, we can say that it does not have an essence at all, but is pure being And if it does not have an essence, then it does not belong in any genus: God and creatures have nothing in common and ‘being’ cannot be applied to necessary and contingent being in the same sense Since essence and quiddity are the same, the supreme being does not have a quiddity: that is to say, there is no answer to the question ‘What is God?’ (Metaph 344–7) Anselm’s Proof of God Avicenna’s natural theology was enormously fertile: theories to be found in philosophers of religion during the succeeding ten centuries can often to be shown to be (often unwitting) developments of ideas that are Wrst found in his writings But one theologian whose ideas bear a remarkable resemblance to his had certainly never read him This was Anselm, who was born four years before Avicenna’s death, and who died forty years before Avicenna’s works were translated into Latin The Arabic word for existence, ‘anniya’, is translated into Latin as ‘anitas’—it is what answers to the question ‘An est ¼ ‘Is there a ?’ just as quidditas is what answers to ‘Quid est’ ¼ ‘What is a ?’ ‘Anity’ has never taken out English citizenship as ‘Quiddity’ has; if one wanted to coin a word it would have to be ‘ifness’—what tells us if there is a God 290