The forms in intellect are some kind of blueprint or model on which the physical world is based, and something needs to come along and shape the matter in accordance with that blueprint. What does that is soul.

Before the 3rd century you're having several philosophical schools still as a going concern. You have not only the Platonists and the Aristotelians but you have Scepticism, you have Stoicism, you even have a little bit of Epicureanism. And what happens after Plotinus is that everybody becomes a Neo-Platonist. So if we then go forward to the Islamic world for example, Plotinus is immensely influential, and Neo-Platonism becomes at least one major component of mainstream Islamic philosophy as well.

Basically the problem is that if the intellect is looking at or beholding the forms, what it will get is some kind of representation or image of the forms, but it won't actually have the forms, it won't touch them as it were, or it won't incorporate them.

Unlike later Neo-Platonists, Plotinus says that our souls are always connected to the universal intellect and that we never really fall away.

The soul is the principle of life, and it's also something much closer to our own awareness and consciousness of our existence because fundamentally for Plotinus what we are is souls, we're not intellects.

If you think about even very common examples like, say, something that you would build, like a clock or a car or a group of people trying to accomplish something, it fails when its unity breaks down. So when it stops having a single form, which is functioning all together, then it sort of falls apart into discrete elements.

The intellect must be different from the soul.