 Avicenna concludes further along these lines that God, the being whose existence is necessary, is “a unity, while everything else is a composite duality” (see HM, H 247). To draw out the idea of God's unity, Avicenna emphasizes that God alone is the essence that is one with existence, whereas all other things enjoy an existence that is, on the contrary, separate from their essence. In speaking about this feature of non-God subjects, Avicenna speaks of existence being added to essence, a claim that has often wrongly been interpreted as suggesting that existence is for Avicenna literally an accident (see Rahman 1958; Morewedge 1972). The details of this misreading aside, the echo of this Avicennian insight can certainly be heard in Maimonides' own description of existence as “an accident attaching to what exists,” as well as in his repeatedly claiming (as above) that there is no “superadded notion” to God's purely singular and unchanging essence (G 1.57, P 132). Maimonides further emphasizes along these lines that attributes used to describe God are “remote from the essence of the thing of which it is predicated,” and that such descriptions do not at all signify “differing notions subsisting within the essence of the agent” (G 1.52, P 378). Further mirroring the Avicennian ideas of divine necessity and essential unity, Maimonides adds: