Matthew Arnold: What are the eternal objects of Poetry?

What are the eternal objects of Poetry, among all nations, and at all times? They are actions; human actions; possessing an inherent interest in themselves, and which are to be communicated in an interesting manner by the art of the Poet. Vainly will the latter imagine that he has everything in  his own power; that he can make an intrinsically inferior action equally delightful with a more excellent one by his treatment of it: he may indeed compel us to admire his skill, but his work will possess, with itself, an incurable defect.

     --Matthew Arnold (1822-1888), in the Author's Preface to The Poems of Matthew Arnold, 1840-1866, published 1908.