“Treacherous” is a pretty strong word to use when talking about a pronoun. But that’s how writer Malcolm Cowley described “us” and “we” in the introduction to his 1934 novel The Dream of the Golden Mountains. The possibility for deception and betrayal, explains Professor of English Bonnie Costello, comes from the ambiguous nature of the first-person plural in English.

“We don’t know just by the mark on the page what is included or excluded from it,” says Costello. “In other languages, you can know. There are different words depending on who is included. In English, ‘we’ can be royal or communal, universal or local, intimate or public, personal or impersonal, inclusive or exclusive.”

Consider the difference between, say, Barack Obama’s campaign slogan—“Yes we can,” which clearly aims to unite the speaker and the listener in a common cause (though whether it’s a rallying cry for Democrats or for all citizens is open to debate)—and the following lines from “The Moose,” a poem by Elizabeth Bishop in which the speaker watches a moose watching the bus she’s riding in and wonders:

Why do we feel
(we all feel) this sweet
sensation of joy?

This “we” is much more open to interpretation. “Does it include the moose?” asks Costello. “The reader? The people on the bus? Who does it include?”

Bishop is one of three poets—along with W. H. Auden and Wallace Stevens—that Costello intends to focus on in her next book, Private Faces in Public Places, with support from the American Council of Learned Societies and the Cullman Center at the New York Public Library. The real subject of the book, however, is not the poets themselves but the humble two-letter word “we,” and the varied uses to which it was put in lyrical poetry written between the Depression and the end of World War II.

“In English, ‘we’ can be royal or com­munal, universal or local, intimate or public, personal or impersonal, inclusive or exclusive.” Bonnie Costello

Lyrical poetry is all about feeling and emotion, and—unlike epic and tragic poems, which concentrate on the heroic deeds and suffering of others—it is often highly personal. For this reason, most literary criticism about lyrical poetry has concentrated on the use of the first-person singular. “Critics have long focused on the ‘I’ as the identifying feature of lyric, and then more recently on the construction of a self through a gesture of address to a ‘you,’” says Costello. “But I found no one talking about the ‘we.’”

The 1930s offer an especially fruitful backdrop for such study, Costello continues, “because of all the pressures of fascism and collectivism. On the one hand, there was a desire among many poets to make poetry public—to provoke change and develop some sort of community. But on the other hand, poets were wary of false universals and the oppressive power of the faceless crowd.”

Bishop’s approach, says Costello, is to interrogate the concept of “we” by provoking the kinds of questions raised above, without offering any definitive answers. Auden, too, tests the limits of “we” in his poetry, ultimately deciding that community is possible.

“Auden largely abandoned the political function of poetry,” Costello says, “but he never abandoned the ethical function of poetry, which requires a regard for others, and a sense of what is between us.”