Full Idea
In his theory fire is said independently to be an element, since it is not formed together with another one, whereas according to the earlier theory fire is formed with other elements.
Gist of Idea
Fire is a separate element, not formed with others (as was previously believed)
Source
report of Chrysippus (fragments/reports [c.240 BCE]) by John Stobaeus - Anthology 1.10.16c
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.97
A Reaction
The point is that fire precedes the other elements, and is superior to them.
Related Idea
Idea 20827 The cosmos is regularly consumed and reorganised by the primary fire [Stoic school, by Aristocles]