Assuming there is an intellect, we're clearly not this universal intellect or we would know it. So that's one function of soul.

People often talk about Plotinus' system. The reason they do this is that Plotinus postulated a kind of series or chain of principles, so at the top there's what he called the One. Below the One is what he called Intellect. Below Intellect is Soul, and the effect of the soul is the physical world that we actually live in.

Who you really are, is an immaterial soul and the body is an external thing that's sort of an encrustation your soul. So this has important implications for Plotinus' ethics, because his ethics are basically all about encouraging us to turn away from the body and turn towards these higher principles, so universal soul, universal intellect and ultimately the One.

The idea is that to grasp an idea like equality or justice, you can't look at the equal and just or unjust things in the world around you, you have to somehow ascend to or maybe remember some kind of idea of equality and justice and this would be a Platonic form, and it would be different from the things that partake in the form.

Just the way you might look at a painting and see the painting, and the painting is outside you, so this immaterial intellect would see the forms and behold them, as if they were standing before it. And Plotinus said that that can't be right because it falls prey to sceptical objections.

Soul puts the determination or forms or images of forms, into matter.

The forms are part of the mind, or really are the mind, they're just the contents of this universal night.