One important recurring theme in Twentieth Century Pleasures is that of emotion in poetry. Hass discusses the emotional impact of poems, both in terms of the emotion that the poet feels while producing the work, as well as the various emotional impacts poems make on different readers. Hass also remarks on the evolving effects a poem can make on a single reader over time. For instance, poems evoke nostalgia. Often when we read a familiar poem, it brings us back to the time and place when we were first introduced to the poem. He uses Kipling’s poem Gunga Din as an example. For Hass, it recalls memories of his brother, who loved that poem. He also says that the power of some poems is that the emotions they convey change as the reader digs deeper and tries to look below the surface. In the case of Robert Lowell’s “Fourth of July in Maine,” the emotional effects deepen on closer reading. Hass reveals how five simple words—“life is much the same”—can convey affection, pathos, and even terror. In the essay “Transtromer’s Baltics: Making a Form of Time,” he discusses the emotional impact the poem has on him. The implication is that emotional responses are subjective—the impact will be different for other readers. Reflecting on Transtromer’s intended connotations of snow, Hass remarks, “I had hardly seen snow until I was eighteen… Because it does not belong to childhood, it calls up no longing.”

As a poet himself, Hass spends considerable time discussing the poetic process, the choices behind the linguistic construction of a given poem. He pays a lot of attention to the way the poem is written—to how the words come together on the page and ultimately impact the reader. Hass is consistently interested in the musical effects of verse. Reading Lowell’s “The Quaker Graveyard in Nantucket,” Hass refers to “the melody of the sound of the words in the poem” and “the nervous restlessness of the rhyming.” Remarking on work by Stanley Kunitz, Hass remarks how “the music of many of these poems is courtly, rich, formal, the imagery generalized.” In other cases, Hass considers how writers work through their process in notebooks.

Hass discusses having read certain poems with one interpretation and then, perhaps years later, especially after learning something more about the poet’s life, rereading the poem in a new light. For instance, he views religion as an important contextual element to illuminate the significance of a poem. Discussing “The Quaker Graveyard in Nantucket,” Hass says that when he was younger, he “didn’t know that Lowell was a convert to Catholicism or that this was a momentous rejection of his heritage.” In the same way, war is another element that often can provide contextual meaning to poems. Some poems cannot be read without knowing that the poet spent years fighting or struggling with grief. There are other factors that give poems contextual meaning. In the essay “Transtromer’s Baltics: Making a Form of Time,” Hass discusses the poem “Passport to the War,” writing, “the context suggested by the companion poems is a painful and rancorous divorce.” Such key information arrives from outside the poem itself—an enriching mode of reading, Hass argues.