The paper that is being referred above is "Ode on a Grecian Urn" and "On Seeing the Elgin Marbles" which are poems of John Keats. In the statement, it states the difference between the two wherein "Ode on a Grecian Urn" refers to art as an unchanging truth and "On Seeing the Elgin Marbles" refers to art that changes over time. In this case, the paper states the poems THEMES.
