Much has been made of Mr. Obama’s eloquence — his ability to use words in his speeches to persuade and uplift and inspire. But his appreciation of the magic of language and his ardent love of reading have not only endowed him with a rare ability to communicate his ideas to millions of Americans while contextualizing complex ideas about race and religion, they have also shaped his sense of who he is and his apprehension of the world.

Mr. Obama’s first book, “Dreams From My Father” (which surely stands as the most evocative, lyrical and candid autobiography written by a future president), suggests that throughout his life he has turned to books as a way of acquiring insights and information from others — as a means of breaking out of the bubble of self-hood and, more recently, the bubble of power and fame. He recalls that he read James Baldwin, Ralph Ellison, Langston Hughes, Richard Wright and W. E. B. Du Bois when he was an adolescent in an effort to come to terms with his racial identity and that later, during an ascetic phase in college, he immersed himself in the works of thinkers like Nietzsche and St. Augustine in a spiritual-intellectual search to figure out what he truly believed.

As a boy growing up in Indonesia, Mr. Obama learned about the American civil rights movement through books his mother gave him. Later, as a fledgling community organizer in Chicago, he found inspiration in “Parting the Waters,” the first installment of Taylor Branch’s multivolume biography of the Rev. Dr. Martin Luther King Jr.

More recently, books have supplied Mr. Obama with some concrete ideas about governance: it’s been widely reported that “Team of Rivals,” Doris Kearns Goodwin’s book about Abraham Lincoln’s decision to include former opponents in his cabinet, informed Mr. Obama’s decision to name his chief Democratic rival, Hillary Rodham Clinton, as Secretary of State. In other cases, books about F. D. R.’s first hundred days in office and Steve Coll’s “Ghost Wars,“ about Afghanistan and the C.I.A., have provided useful background material on some of the myriad challenges Mr. Obama will face upon taking office.

Mr. Obama tends to take a magpie approach to reading — ruminating upon writers’ ideas and picking and choosing those that flesh out his vision of the world or open promising new avenues of inquiry.

His predecessor, George W. Bush, in contrast, tended to race through books in competitions with Karl Rove (who recently boasted that he beat the president by reading 110 books to Mr. Bush’s 95 in 2006), or passionately embrace an author’s thesis as an idée fixe. Mr. Bush and many of his aides favored prescriptive books — Natan Sharansky’s “Case for Democracy,” which pressed the case for promoting democracy around the world, say, or Eliot A. Cohen’s “Supreme Command,” which argued that political strategy should drive military strategy. Mr. Obama, on the other hand, has tended to look to non-ideological histories and philosophical works that address complex problems without any easy solutions, like Reinhold Niebuhr’s writings, which emphasize the ambivalent nature of human beings and the dangers of willful innocence and infallibility.

What’s more, Mr. Obama’s love of fiction and poetry — Shakespeare’s plays, Herman Melville’s “Moby-Dick” and Marilynne Robinson‘s “Gilead” are mentioned on his Facebook page, along with the Bible, Lincoln’s collected writings and Emerson’s “Self Reliance“ — has not only given him a heightened awareness of language. It has also imbued him with a tragic sense of history and a sense of the ambiguities of the human condition quite unlike the Manichean view of the world so often invoked by Mr. Bush.

Mr. Obama has said that he wrote “very bad poetry” in college and his biographer David Mendell suggests that he once “harbored some thoughts of writing fiction as an avocation.” For that matter, “Dreams From My Father” evinces an instinctive storytelling talent (which would later serve the author well on the campaign trail) and that odd combination of empathy and detachment gifted novelists possess. In that memoir, Mr. Obama seamlessly managed to convey points of view different from his own (a harbinger, perhaps, of his promises to bridge partisan divides and his ability to channel voters’ hopes and dreams) while conjuring the many places he lived during his peripatetic childhood. He is at once the solitary outsider who learns to stop pressing his nose to the glass and the coolly omniscient observer providing us with a choral view of his past.

As Baldwin once observed, language is both “a political instrument, means, and proof of power,” and “the most vivid and crucial key to identity: it reveals the private identity, and connects one with, or divorces one from, the larger, public, or communal identity.”

For Mr. Obama, whose improbable life story many voters regard as the embodiment of the American Dream, identity and the relationship between the personal and the public remain crucial issues. Indeed, “Dreams From My Father,” written before he entered politics, was both a searching bildungsroman and an autobiographical quest to understand his roots — a quest in which he cast himself as both a Telemachus in search of his father and an Odysseus in search of a home.

Like “Dreams From My Father,” many of the novels Mr. Obama reportedly admires deal with the question of identity: Toni Morrison’s “Song of Solomon” concerns a man’s efforts to discover his origins and come to terms with his roots; Doris Lessing’s “Golden Notebook” recounts a woman’s struggles to articulate her own sense of self; and Ellison’s “Invisible Man” grapples with the difficulty of self-definition in a race-conscious America and the possibility of transcendence. The poems of Elizabeth Alexander, whom Mr. Obama chose as his inaugural poet, probe the intersection between the private and the political, time present and time past, while the verse of Derek Walcott (a copy of whose collected poems was recently glimpsed in Mr. Obama’s hands) explores what it means to be a “divided child,” caught on the margins of different cultures, dislocated and rootless perhaps, but free to invent a new self.

This notion of self-creation is a deeply American one — a founding principle of this country, and a trope addressed by such classic works as “The Great Gatsby” — and it seems to exert a strong hold on Mr. Obama’s imagination.

In a 2005 essay in Time magazine, he wrote of the humble beginnings that he and Lincoln shared, adding that the 16th president reminded him of “a larger, fundamental element of American life — the enduring belief that we can constantly remake ourselves to fit our larger dreams.”

Though some critics have taken Mr. Obama to task for self-consciously italicizing parallels between himself and Lincoln, there are in fact a host of uncanny correspondences between these two former Illinois state legislators who had short stints in Congress under their belts before coming to national prominence with speeches showcasing their eloquence: two cool, self-contained men, who managed to stay calm and graceful under pressure; two stoics embracing the virtues of moderation and balance; two relatively new politicians who were initially criticized for their lack of experience and for questioning an invasion of a country that, in Lincoln’s words, was “in no way molesting, or menacing the U.S.”

As Fred Kaplan’s illuminating new biography (“Lincoln: The Biography of a Writer”) makes clear, Lincoln, like Mr. Obama, was a lifelong lover of books, indelibly shaped by his reading — most notably, in his case, the Bible and Shakespeare — which honed his poetic sense of language and his philosophical view of the world. Both men employ a densely allusive prose, richly embedded with the fruit of their reading, and both use language as a tool by which to explore and define themselves. Eventually in Lincoln’s case, Mr. Kaplan notes, “the tool, the toolmaker, and the tool user became inseparably one. He became what his language made him.”