The Four Sub-Lunary Elements of the Heavens

Aristotle says the heavens are mostly fire, but there's a very different kind of fire in the heavens. And this fire is almost immaterial, which means it's going to allow itself to create a kind of to engage in a harmonious relationship with soul such that there won't be any flux. Plotinus uses this as an opportunity to really investigate the constitution of the heavens and he pushes Plato's answer in Aristotle's direction. So really he's just trying to support that through some kind of theory of the material. It's almost like he thinks the heavens are some kind of intermediary or compromise between intelligible things and physical things.