Full Idea
Wisdom [phronesis] is correctly given the name 'kalon' [beautiful], since it performs the works that we say are beautiful and welcome as such.
Gist of Idea
Wisdom is called 'beautiful', because it performs fine works
Source
Plato (Cratylus [c.375 BCE], 416d)
Book Reference
Plato: 'Complete Works', ed/tr. Cooper,John M. [Hackett 1997], p.134
A Reaction
'Phronesis' in Aristotle is more like prudence, or common sense, rather than wisdom ['sophia']. 'Kalon' also means fine or noble. This translation seems fair enough, though.