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

Plotinus is usually called the Founder of Neo Platonism and what that means is that in this philosophical circle, he was founding a kind of renewed attempt to understand the thought of Plato which however they were combining with the thought of other philosophers, including Aristotle, the Stoics and Pythagoreans and so on.

Once you're in a kind of revealed religious tradition, you wind up having to explain how the things said about God in the Bible or the Qur'an or whatever religious text you're dealing with, why these statements are true.

In fact one of the things about Plotinus is that he maybe not singlehandedly, but I think more than anyone else, killed off the variety and dissension among the philosophical schools of antiquity.

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.

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.

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