Plotinos · Plotinus
WHY THE HEAVENS MOVE IN A CIRCLE.
Now, if the heavens possess the Soul, wherever they are, what urges them to move in a circle? Surely because the Soul is not exclusively in a determinate place (and the world does not exclusively in one place desire to possess her). Besides, if the power of the Soul revolve around the centre, it is once more evident that the heavens would move in a circle. DIFFERENCE BETWEEN THE CENTRE OF THE SOUL AND THE BODY. Besides, when we speak of the Soul, we must not understand the term "centre" in the same sense as when it is used of the body. For the Soul, the centre is the focus of (the intelligence) whence radiates a second life (that is, the Soul); as to the body, it is a locality (the centre of the world). Since, however, both soul and body need a centre, we are forced to use this word in an analogous meaning which may suit both of them. Speaking strictly, however, a centre can exist only for a spherical body, and the analogy consists in this, that the latter, like the Soul, effects a reflection upon itself. In this case, the Soul moves around the divinity, embraces Him, and clings to Him with all her might; for everything depends from Him. But, as she cannot unite herself to Him, she moves around Him.
Text from Project Gutenberg, public domain in the United States.