Full Idea
Fineness is the father of goodness.
Clarification
'Fineness' is the Greek word 'kalos', which also translates as 'beauty'
Gist of Idea
What is fine is the parent of goodness
Source
Plato (Hippias Major [c.382 BCE], 297b)
Book Reference
Plato: 'Early Socratic Dialogues', ed/tr. Saunders,Trevor J [Penguin 1987], p.255