Plotinus taught that there is a supreme, totally transcendent "One", containing no division, multiplicity or distinction; beyond all categories of being and non-being. His "One" "cannot be any existing thing", nor is it merely the sum of all things [compare the Stoic doctrine of disbelief in non-material existence], but "is prior to all existents". Plotinus identified his "One" with the concept of 'Good' and the principle of 'Beauty'. [I.6.9]
His "One" concept encompassed thinker and object. Even the self-contemplating intelligence (the noesis of the nous) must contain duality. "Once you have uttered 'The Good,' add no further thought: by any addition, and in proportion to that addition, you introduce a deficiency." [III.8.11] Plotinus denies sentience, self-awareness or any other action (ergon) to the One [V.6.6]. Rather, if we insist on describing it further, we must call the One a sheer potentiality (dynamis) or without which nothing could exist. [III.8.10] As Plotinus explains in both places and elsewhere [e.g. V.6.3], it is impossible for the One to be Being or a self-aware Creator God. At [V.6.4], Plotinus compared the One to "light", the Divine Nous (first will towards Good) to the "Sun", and lastly the Soul to the "Moon" whose light is merely a "derivative conglomeration of light from the 'Sun'". The first light could exist without any celestial body.
The One, being beyond all attributes including being and non-being, is the source of the world—but not . . . more