MacKenna-Plotinus: Geometria

Geometry, the science of the Intellectual entities, holds place There: so, too, philosophy, whose high concern is Being. Enneads  : V IX. 11

Geometry and arithmetic are, we shall maintain, of a twofold character; in their earthly types they rank with Sensible Quality, but in so far as they are functions of pure Soul, they necessarily belong to that other world in close proximity to the Intellectual. This, too, is in Plato’s view the case with music and astronomy. Enneads: VI III. 16