"There but for the grace of God go I."

It's a thing people say. You see homeless people in the train station, or victims of war, disease, or misfortune. And you realize it could have been you, yet somehow it isn't.

But who ever actually checks it out?

Wes Moore did.

Wes Moore is the name of at least two men. The two were born less than a year apart in Baltimore, separated by only a few blocks. One is now in the Maryland Correctional Institution near Jessup, Md., serving life for murdering a policeman. The other is a graduate of Valley Forge Military Academy, a Rhodes Scholar, a graduate of Johns Hopkins University and Oxford University, a businessman with a start-up called BridgeEdU, and a host of Beyond Belief on Oprah Winfrey's OWN. He lives in his beloved Baltimore with wife Dawn, daughter Mia, and son James. And he knocks himself out for city kids.

The second Wes Moore got to wondering: What was the difference between the two Wes Moores?

His book The Other Wes Moore: One Name, Two Fates became a bestseller in 2010. It's a meditation on first and last chances, opportunities taken and missed, human destiny.

And he has just published The Work: My Search for a Life That Matters (Spiegel and Grau, $25), which extends the discussion, asking: How do we get meaning from work, and work that gives life meaning?

Moore, 36, writes that the other man's story "could have been mine. The tragedy is that my story could have been his."

When Moore was 4, he watched as his father, terribly misdiagnosed at a local hospital, died of a viral infection. At 12, the boy was failing school and getting in trouble on the Bronx streets. But at 22, the man was a Rhodes Scholar heading for a master of letters in international relations at Oxford.

What turned it around?

"In the Bronx, I was disillusioned. I couldn't fit in," Moore says by phone from Baltimore. "Gangs are structured a lot like Fortune 500 companies: Everyone is trying for recognition and preferment. It was just the wrong kind of recognition."

What made the difference? He writes that because of trouble and incarceration when young, the other Wes Moore had "never thought long term about his life at all." And at one point, the second Wes Moore says, neither had he. "I was not seeing my life very clearly."

His mother, Joy Moore, with help from her parents, sent him to Valley Forge.

The people in his life stepped up. Michael Murnane, a retired lieutenant colonel, taught Wes Moore at Valley Forge.

"He's been greatly influenced by a lot of women in his life," Murnane says. "A terrific mother and two dynamic sisters." Latyrus Hill, Moore's older mentor at Valley Forge, says: "His mother said, 'Not my son. This isn't going to happen to my child.' "

It didn't start well, Murnane says. "He ran away more times than we could count."

Hill says, "After repeated attempts at running away, getting lost in the Pennsylvania woods, and about dying of fright of being attacked by wild animals, he finally said, 'OK, if I'm going to be here, I'm going to do it right.' "

"I finally had a sense of guidance and direction, from people who held huge expectations of me," Moore says. Which led to the thing the other Wes Moore never had: "Valley Forge gave me a chance to think differently about what I wanted to do with my life."

A gift was revealed: leadership. "Every single year," Murnane says, "his class voted him to be their leader, president of the class. So his peers recognized him and the way he stood out."

He kept leading. He was a captain in the 1st Brigade of the 82d Airborne Division in Afghanistan ("Getting shot at focuses you on the meaning of your life"). As a White House Fellow, he was special assistant to then-Secretary of State Condoleezza Rice. He is a frequent media voice on children and education. He makes appearances in Baltimore schools, advising kids on how to start thinking of what they will do with their lives.

Moore insists that his is more than a feel-good story, a platform for platitudes. Inspiration, yes, is great - his show, Beyond Belief, "lets me profile remarkable people and their motivation for doing remarkable things," he says. But after he met the other Wes Moore in 2000, becoming his correspondent and through-the-glass friend, something kept eating him.

It was what the other Wes Moore never had, what kids like him never get. Mustafa Shafi Riffat, who worked in investment banking with Moore at Citibank, says, "His entire philosophy is that we all make choices in life, but the one choice you can't make is where and when we're born, and who we're born to."

Which brings us to The Work, and what the author Wes Moore is doing now. The Work tells stories of people who have discovered careers, or changed careers, or found their passion. It tells why Moore left a lucrative but unfulfilling job at Citibank and went to Afghanistan. (Riffat says, "He turned and walked away. A lot of people talk about doing that. He did it.") It tells of "not just working to live, but finding the work of our lives." You can bet the italics are his.

Is this another rah-rah, yes-we-can book? Moore wants it to be more. "I wanted to give people a concrete takeaway. A practical baseline for people asking, 'So what am I supposed to do?' " He concludes with a "Resource Guide" of more than 200 organizations that do crucial work with young people. "Here are places you can find engagement," he says, "places that can serve your needs, places you can get help or volunteer to give help."

And he is working on BridgeEdU, a first-year college program that combines coaching, internships, and core courses to prepare students for college.

"The goal is to improve persistence in higher education, especially for first-generation students, or those who have tried and not succeeded before, and students from urban backgrounds, where they haven't had the resources or networking successful students have," says Tisha Edwards, a former superintendent of Baltimore city schools who now advises Moore with BridgeEdU. "Wes is trying to figure out how to create more success for these kids in college. He's conscious that many come from circumstances that leave them without the skills and support system other kids have."

BridgeEdU is now a pilot program in Baltimore, with aims to go national. "He's tireless," Murnane says, "always going into the schools, talking to the kids."

"He will fight tooth and nail," Riffat says, "if it helps one child."

It's more than giving back, Moore says: "It's seeing life clearly, and being able to teach others what I've learned."

He stays in touch with the other Wes Moore: "I still see him and write letters for him. Prison is a challenge for him, 14 years into his life sentence. He's trying to focus on how his life can affect others in good ways."

So both Wes Moores are now working for the sake of others. As the author Wes Moore puts it in The Work: "How we spend our days is how we spend our lives . . .. "