Plotinus held that to wish for the absence of ‘evil’ was to wish that there be nothing at all. That if there is to be a world at all, that that world MUST contain the evil(s) it does simply because it is made out of matter. That there could be no essential, no ultimate essence of evil because it has no ‘Form’ (in the Platonic sense), so really there’s no such thing as evil qua evil.
So when we talk about evil, what we are really talking about is a perception of the absence of goodness - and the degree to which we perceive it to be evil is the ability to perceive how much goodness is missing.
Now Plotinus held that matter (everything) originates from a 'Source', which he termed ‘The One’ or ‘The Good’, and that it (the source) holds no will, no desire, no intention, not even any sentience. So nothing like the conventional theist interpretation of a creator God - a being that actively willed the universe into existence. It seems to be more like a light bulb - if it’s on, you get light, you just do. If it’s off, there’s nothing. So, insofar as things exist at all, they partake of the goodness but it is hardly the fault of a light bulb (goodness), say, if a dirty mirror does not reflect that light (goodness) perfectly.
I can’t argue with that. I don’t think we know what matter is, do we, or where it comes from, if it comes from anywhere? Einstein expresses some of that here:
“Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious.” Albert Einstein - Berlin 1927
Plotinus is side-stepping the logical and evidential problems of evil with which atheists love to plague theists so frequently. But insofar as this is a very deist interpretation of reality we can’t say much about it except to note that Plotinus thinks that the metaphysics of physical objects (humans included), means that they must be imperfect to some greater or lesser degree and that that movement towards a greater reflection of the good is our job and that it is a very rational one.
Or else, he was just trying to make The Matrix and hadn’t figured out who Neo was yet. :-)