Maimonides expresses the view that being is goodness; evil is a deprivation of being and goodness. This view is prominent in Neoplatonism but has strong roots in Aristotle as well.
While Maimonides problematizes moral language of good and evil, he makes use of an ontological sense of Necessary Existence as the absolute good. Plotinus wrote that beings are the beautiful. Avicenna adds that the pure good is Necessary Existence, which is free of deficiency, as it has no possibility of lacking existence. This notion has a strong Aristotelian core. Despite his strictures on language about the divine, Maimonides allows himself to express this vision—an affective-aesthetic appreciation as well as a purely cognitive one. Being is the absolute good, the source of ontological beauty and value.