 With this theme of a loss of pleasure and inevitable death , the poem , according to Claude <unk> , describes " the <unk> of the romantic escape from the world of reality to the world of ideal beauty " . Earl <unk> essentially agrees with <unk> , but he extended his <unk> of the poem to incorporate the themes of Keats 's Mansion of Many Apartments when he says , " the core of the poem is the search for the mystery , the unsuccessful quest for light within its darkness " and this " leads only to an increasing darkness , or a growing recognition of how impenetrable the mystery is to mortals . " With these views in mind , the poem recalls Keats 's earlier view of pleasure and an optimistic view of poetry found within his earlier poems , especially Sleep and Poetry , and rejects them . This loss of pleasure and incorporation of death imagery lends the poem a dark air , which connects " Ode to a Nightingale " with Keats ' other poems that discuss the demonic nature of poetic imagination , including <unk> . In the poem , Keats imagines the loss of the physical world and sees himself dead — he uses an abrupt , almost brutal word for it — as a " sod " over which the nightingale sings . The contrast between the immortal nightingale and mortal man , sitting in his garden , is made all the more acute by an effort of the imagination . 
