Averroes does not accept Avicenna’s argument for the existence of the Necessary Bing. Some maintain that Averroes disagreed with Avicenna, since he could not understand the relationship between essence and existence and could not make sense of the essential possibility and that he did not distinguish between potential possibility and essential possibility. In this paper, we argue that Averroes knew essential possibility as well as the relationship between essence and existence, but philosophy in that age failed to present and resolve the problem of the fundamental reality of existence and the problem of making existence .So, essential possibility could not be a basis for this argument. To judge between Avicenna and Averroes, we must not concentrate on matters that were resolved then, because these foundations had not been examined and the argument was based on these foundations.
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