Plotinus thought that the entire world has a single soul. He also thought that each animal and plant and of course human, has an individual soul.

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

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.

When you're seeking after bodily pleasure of food and drink for example, this is going to prevent you from doing what you should be doing which is contemplating.

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

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

The world around you is some kind of distraction at best, and evil at worst, and you should be turning away from it.