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.