Final answer:
The central idea of 'Ode on a Grecian Urn' is the relationship between beauty, truth, and art. The poem explores how beauty transcends time and mortality. The urn is seen as a symbol of beauty and a source of profound truths.
Step-by-step explanation:
The central idea of John Keats's 'Ode on a Grecian Urn' is the exploration of the relationship between beauty, truth, and art. Keats suggests that beauty is eternal and transcends the limitations of time and mortality.
The last two lines of the poem, 'Beauty is truth, truth beauty,' encapsulate this idea. The urn, as a work of art, is seen as a powerful symbol of beauty that can communicate profound truths to humanity.
This exploration of the interplay between beauty and truth makes the poem a reflection on the nature of art and the enduring power of aesthetic experiences.