Meditations VIII.57
The sun’s light is diffused down, as it seems, yes, and in every direction, yet it does not diffuse itself away. For this diffusion is an extension. At any rate the beams of the Sun are called Extension rays, because they have an extension in space62. And what a ray is you may easily see, if you observe the sun’s light entering through a narrow chink into a darkened room, for it extends straight on, and is as it were brought up against63 any solid body it encounters that cuts off the air beyond. There the ray comes to a standstill, neither slipping off nor sinking down. Such then should be the diffusion and circumfusion of the mind, never a diffusing away but extension, and it should never make a violent or uncontrollable impact against any obstacle it meets with, no, nor collapse, but stand firm and illuminate what receives it. For that which conducts it not on its way will deprive itself wilfully of its beams.
- 62.A false etymology. The derivation may be from ἀίσσω or ἄγνυμι.
Marcus derives aktines, “rays,” from ekteinesthai, “to be extended”; Haines’s alternatives are aissō, “to dart,” and agnymi, “to break.”
- 63.διαιρεῖται (the manuscripts) would mean apparently cut or broken.