Keats ended his Ode to a Grecian Urn with the lines:
Beauty is truth, truth beauty - that is all
Ye know on earth, and all ye need to know
When was the equivalence, or relation between beauty and truth posited? I've taken it to be a feature of neo-Platonism but is this in fact true?
Is it in any of Plato's own work (which would be strange given his description of art as mimesis) or in Plotinus?
Or is it an interpretation from the Romantic period in literary and artistic circles? A partial explication of it is given in the beginning of Hardy's (the novelist and poet) last novel, The Well-Beloved.
A similar discourse about truth and beauty is there in mathematics. Hardy (the mathematician) said for example:
There is no permanent place in the world for ugly mathematics
Of course Hardy himself might be recalling romantic discourse here.