Marsilio Ficino’s Platonic Theology, Volume II

25Imagine a geometrical point. Because it regards equally every part of the place surrounding it, if it is moved through any part, it moves in a circle; and what was a point appears to have become a circumference. Here the circumference is a point running round and unfolded outward, while the point is a circumference rolled together upon a stable hinge. Imagine again a spark of invisible light. Because it exists above every place, it pours itself equally into every part of place; and as it moves in a circle it becomes a flaming orb—an orb, I say, manifest to the eyes. Here the spark is a compressed flame, and the flame a spark poured forth. A spark of this kind is the soul; the flame is the ethereal body. As great as the variety of spiritual light in rational souls is, so great is the variety of visible light in the celestial bodies proper to them. That visible light follows the spiritual light just as a pale circle in the clouds follows the light of the moon.

26The difference among rational souls is this: the souls of the fixed stars and planets are surrounded by a luminous body alone, while the others are surrounded by two bodies, one luminous and one opaque—or certainly one most luminous and the other less luminous. It seems to be, as it were, the same light: while it remains a spark, it senses but is not sensed; when it is unfolded into flame, however, it is sensed, but the flame itself senses nothing further. Just as anyone who saw a flame yet denied that he saw a spark would be devoid of sense, so anyone who looks upon the ethereal globes as so many circuits of souls yet fails to perceive the souls within them as centers—and does not grant that souls are enfolded globes of lights, while globes are unfolded souls—will be devoid of a soul. Heraclitus signified this as follows: αὐγὴ ξηρὴ ψυχὴ σοφωτάτη, that is, ‘A dry light is the wisest soul.’ Hence it follows that nothing is more pleasing or more wonderful to the mind than light, and that while the mind dwells on earth it can live nowhere but in the light of spirits. Here, then, you have also discovered the soul as an invisible, life-giving, sentient, intelligible, and intelligent light.