If we're going to go down the route of discussing words and their relationship to physical phenomenon and mental concepts, I think we'll need to review the following papers:
David Sedley, On Nature, Book 28
File
On Nature Book 28 - Reconstruction By David Sedley - 1973 Article

Sedley reconstruction of fragments from Book 28
Cassius
And maybe this one:
“New Evidence for the Epicurean Theory of the Origin of Language: Philodemus, On Poems 5 (PHerc. 403, fr. 5, col. i),” Cronache Ercolanesi (2015) 45: 67-84.
“New Evidence for the Epicurean Theory of the Origin of Language: Philodemus, On Poems 5 (PHerc. 403, fr. 5, col. i),” Cronache Ercolanesi (2015) 45: 67-84.
This article presents new evidence from the Herculaneum papyri for the Epicurean theory on the origin and development of language. After a brief overview of…
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