The intellect must be different from the soul.

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.

There's a stronger and more kind of controversial element of Plotinus' view of matter, which is that he actually identifies it with evil, or at least the principle of evil, and the reason for this is that he thinks that the the One, the highest principle, can also be thought of as the Good, and that's kind of surprising like, because he has this negative theology which doesn't allow us to say anything about the One. But he believes that it can be seen as the principle of goodness as well as unity, and that if you think about it, goodness and unity sort of go along with each other.

Plotinus, when he thinks about mind or intellect, the Greek word is 'nous', he thinks about something that's very different, it's much more elevated and special, more abstract, you might say more philosophical than the very broad range of mental events that we talk about in contemporary philosophy of mind.

If you think about for example, proportionality and beauty, things like that, these seem to be some kind of representations of a kind of unity.

The soul must be distinct from intellect because even at its best, what the soul does when it's thinking, is it thinks linguistically, it thinks in a temporarily extended way, so it for example, might go through the steps of an argument chain, as if you were going through a syllogism and seeing that something followed from the premises, whereas intellect simply grasps the forms.

For Plotinus, what really exists are the Platonic forms, so the true nature or form of things like justice, beauty, maybe numbers, things like that, and these he associates with the intellect because they're the objects of intellect, they are things that intellect can think about.