From the book
Stobaeus, Volume I
John Stobaeus · Diotimos Editions · 2026
Browse this book’s lexicon →Ray
ἀκτίς
aktisAktis is a ray or beam of light.
Orientation
At a Glance
- The wordAktis is a ray or beam of light.
- In StobaeusThe report about Diogenes likens the sun to pumice and describes rays from the aether lodging in it.
- In this edition“Ray” preserves the luminous phenomenon without substituting a modern account of radiation.
- A place to beginRays from the aether are received by a porous, pumice-like sun.
- English renderings
- ray; beam
Meaning
Aktis is a ray or beam of light. Different ancient theories explain its origin and physical role differently.
Use in the book
The report about Diogenes likens the sun to pumice and describes rays from the aether lodging in it. Rays therefore arrive at the sun within this account, rather than simply issuing from it. The direction of their movement is essential to understanding the unusual explanation.
Places to read
- I.25.3cRays from the aether are received by a porous, pumice-like sun.
Translation in this edition
“Ray” preserves the luminous phenomenon without substituting a modern account of radiation.
Source note
Wachsmuth, volume I, printed pp. 210. The following claim of extinction by cold is printed under the same attribution without a separate heading specifying an eclipse or solstice.
From the book
Empedocles’ The Testimonia, Volume II
Empedocles of Acragas · Diotimos Editions · 2026
Browse this book’s lexicon →Rays
τῶν ἀκτίνων (tōn aktinōn)
Aktines are rays.
Orientation
At a Glance
- The wordAktines are rays.
- In this workA90 says Empedocles provides grounds both for seeing by rays and for seeing by images.
- In this editionThe edition's commentary calls a simultaneous two-way theory “the honest reading.”
- A place to readLists the ray interpretation alongside the image interpretation, preferring the latter.
Meaning
Aktines are rays. Aëtius uses the word to label one interpretation of how seeing occurs. It is the doxographer's classificatory language; the notice does not quote Empedocles using the term.
Use in the book
A90 says Empedocles provides grounds both for seeing by rays and for seeing by images. The ray reading naturally stands beside the reported fire inside the eye and Aristotle's description of light going out as from a lantern. But Aëtius's statement is an admission about interpretations supported by the source, not a complete account of a ray's route or structure.
The same notice favours the image reading because Empedocles accepts effluences. That preference does not erase the outgoing-light evidence, and neither does it prove that the original poem explicitly combined two developed optical theories. The responsible use of “rays” therefore marks a reception category and a possible direction of physical interaction while leaving the synthesis open.
Places to read
- A 90 (testimony)Aëtius. Lists the ray interpretation alongside the image interpretation, preferring the latter.
- A 91 (polemical)Aristotle, On Sense and Sense-Objects. Describes and challenges the idea of light going out from the eye.
Translation in this edition
The edition's commentary calls a simultaneous two-way theory “the honest reading.” That is a proposed reconstruction; the ancient notice itself says that both interpretations find support.