Full Idea
The Stoics used 'kalon' [fair, i.e. beautiful] as a synonym for 'agathon' [good]
Clarification
'Kalon' normally translates as 'fine' or 'beautiful'
Gist of Idea
Stoics use 'kalon' (beautiful) as a synonym for 'agathon' (good)
Source
comment on Stoic school (fragments/reports [c.200 BCE]) by R.G.Bury - notes on Sextus Empiricus 69:245
Book Reference
Sextus Empiricus: 'Outlines of Pyrrhonism', ed/tr. Bury,R.G. [Prometheus 1990], p.245
A Reaction
I consider this to be a very important idea, which has been lost in modern moral philosophy - even in modern virtue theory. I've seen the suggestion that the best translation of 'kalon' is 'Wow!'. Imagine deeds that elicit 'Wow!'.