As Dan-el Padilla Peralta toggled fluidly between worlds for much of his life — ancient and modern, poor and privileged, Dominican and American — there were times when he managed to forget he was a child without a country.

He found refuge in New York’s libraries, the Greek and Latin texts speaking to him even before he could speak their language. He would copy entire orations, memorizing for inspiration.

But always, the fear would return: He could be deported. His mother brought him to the United States from Santo Domingo, the capital of the Dominican Republic, when he was 4, and they overstayed their tourist visas. He has wrestled with the consequences ever since.

“The drumming of papeles was the background music to my life,” Dr. Padilla said, intoning the Spanish term for legal documents.

Now he hopes that by telling his life story, he will be able to further the discussion on immigration policy, which has become a contentious issue on the presidential campaign trail. In “Undocumented: A Dominican Boy’s Odyssey From a Homeless Shelter to the Ivy League” (Penguin 2015), he recounts the extraordinary arc from poverty to the all-boys Collegiate School in Manhattan, to Princeton, then Oxford, where he earned a masters in philosophy, and Stanford, where he earned a doctorate in classics.

At age 30, Dr. Padilla is at Columbia as a postdoctoral fellow in humanities, and next summer, he will return to Princeton as an assistant professor of classics. He has a work visa, but is not yet a citizen, a status he hopes will soon change because in March, Dr. Padilla married a woman from Sparta, N.J., whom he had dated for six years. He is still waiting for his green card application to be considered.

Dr. Padilla said that his wife, Missy, a social worker, was teasing him recently that he still could not enjoy his success. To explain his pessimism, Dr. Padilla cited Homer’s Iliad, where two jars stood on the floor of Zeus’ palace, one containing bad things, and the other a mixture of good and bad. There was no vessel of all good things.

“I live, in part because of the conditioning of my childhood and adolescence, in this state of expectation that something really bad is about to come our way,” Dr. Padilla said.

His mother, Maria Elena Peralta, came to New York for the end of her high-risk pregnancy when she was carrying Dr. Padilla’s brother, Yando. The boys’ father, frustrated by his low-paying jobs, returned to the Dominican Republic three and a half years later. She risked staying illegally when she saw how her oldest son was already excelling in school.

“It was when his teacher started speaking with me and saying what he was doing in the classroom, I began asking myself, ‘How could I ever return?’ ” Ms. Peralta, 54, said in Spanish with Dr. Padilla translating.

When Ms. Peralta struggled to find work because of her undocumented status, the family had little to eat and lived in homeless shelters and subsidized housing. But her oldest son was happy if he was learning. He rescued books from trash bins, she recalled. At age 8, after finishing “Peter Pan,” he tried to retell the plot, lecturing his 3-year-old brother.

A volunteer art teacher at a homeless shelter in Bushwick, Brooklyn, had noticed young Dan-el reading a book about Napoleon. Impressed and charmed, the teacher, Jeff Cowen, befriended him and steered him to his alma mater, Collegiate.

“He strove for the very best for us, and he did it without any expectation of return,” Ms. Peralta said of Mr. Cowen. “He wanted Dan-el to flourish.”

When Dan-el started Latin as an eighth grader at Collegiate, his teacher, Stephanie Russell, was taken aback at how he had not only read Plato, but also had thoroughly absorbed it. She did not know his background, nor did she care.

Dan-el Padilla moved to the United States when he was a child.

“His intellectual gifts were what jumped out at me,” Dr. Russell said, adding that he was well-liked for his easy generosity.

“He spread an influence around that we were all the better for,” she said. “And all of this while obviously leading a split, double life.”

It is a dichotomy that Dr. Padilla describes in his memoir by mixing slang and earnest prose. He is as fluent in the Fugees as he is in the Fates and recently wrote a weighty article about antiquity’s influence on hip-hop artists (“From Damocles to Socrates”) for the online classics journal Eidelon.

Dr. Padilla can go from opining on Plato to opining on Pedro — as in Pedro Martinez, the Dominican Hall of Fame pitcher. He entertained working for a Major League Baseball team or writing for the analytical-heavy Baseball Prospectus.

Instead, he chose an academic career in one of the more esoteric disciplines. He has spent this summer at Columbia teaching previously incarcerated adults the relevance of the ancient texts. He has not talked about his own story.

“He loves the texts, I mean, I don’t see any time for anything else,” one student, Isaac Scott, 35, said. “He loves this stuff, reading, literature, the ideas, the questioning, the doubts, the ambiguity. He loves when we catch on to something.”

Dr. Padilla did not “come out” as undocumented until his senior year at Princeton, when he told his friends and posted on a Princeton message board, in advance of an article that was later published in The Wall Street Journal. In 2006, he joined an immigrant advocacy movement even as his lawyer, Stephen Yale-Loehr, was trying to find a way for him to be able to return from studying at Oxford. Mr. Yale-Loehr has petitioned for his client’s status at every academic stage.

For Dr. Padilla, the strangest stage may be an actual one. A new musical inspired by his life, “Manuel Versus the Statue of Liberty,” written and produced by a Princeton alumna, Noemi de la Puente, will be performed this week in Manhattan.

The other day, Dr. Padilla met his mother to give her a signed copy of the book, which he dedicated to her. In her confident and petite elegance, it was clear where he got his determination. Ms. Peralta said she began writing her own memoir soon after he was born.

“I said at the time, If I don’t ever finish this, Dan-el will write the story,” Ms. Peralta said. “I would have liked for the narrative to have been one with less suffering, for there to have been less in the way of pain.”

http://www.nytimes.com/2015/07/23/nyregion/from-an-undocumented-boyhood-to-a-doctorate.html