Full Idea
If anything is beautiful other than beauty itself, it is beautiful for no other reason but because it participates in that beautiful.
Clarification
'Beauty' is the Greek word 'kalos', which also translates as 'fine'
Gist of Idea
There is only one source for all beauty
Source
Plato (Phaedo [c.374 BCE], 100c)
Book Reference
Plato: 'The Last Days of Socrates', ed/tr. Tredennick,Hugh [Penguin 1969], p.159
A Reaction
The Greek word will be 'kalon' (beautiful, fine, noble). Like Aristotle, I find it baffling that such diversity could have a single source. Beautiful things have diverse aims.
Related Idea
Idea 514 Beauty is merely animal without intelligence [Democritus (attr)]