By Jessica Ravitz, CNN

The question arose early in British academic A.C. Grayling’s career: What if those ancient compilers who’d made Bibles, the collected religious texts that were translated, edited, arranged and published en masse, had focused instead on assembling the non-religious teachings of civilization’s greatest thinkers?

What if the book that billions have turned to for ethical guidance wasn’t tied to commandments from God or any one particular tradition but instead included the writings of Aristotle, the reflections of Confucius, the poetry of Baudelaire? What would that book look like, and what would it mean?

Decades after he started asking such questions, what Grayling calls “a lifetime’s work” has hit bookshelves. “The Good Book: A Humanist Bible,” subtitled “A Secular Bible” in the United Kingdom, was published this month. Grayling crafted it by using more than a thousand texts representing several hundred authors, collections and traditions.

The Bible would have been “a very different book and may have produced a very different history for mankind,” had it drawn on the work of philosophers and writers as opposed to prophets and apostles, says Grayling, a philosopher and professor at Birkbeck College, University of London, who is an atheist.

“Humanist ethics didn’t claim to be derived from a deity," he says. "(They) tended to start from a sympathetic understanding of human nature and accept that there’s a responsibility that each individual has to work out the values they live by and especially to recognize that the best of our good lives revolve around having good relationships with people.”

Humanists rely on human reason as an alternative to religion or belief in God in attempting to find meaning and purpose in life.

Determined to make his material accessible, Grayling arranged his nearly 600-page "Good Book" much like the Bible, with double columns, chapters (the first is even called Genesis) and short verses. And much like the best-selling King James Bible, which is celebrating its 400th year, his book is written in a type of English that transcends time.

Like the Bible, "The Good Book," opens with a garden scene. But instead of Adam and Eve, Grayling's Genesis invokes Isaac Newton, the British scientist who pioneered the study of gravity.

"It was from the fall of fruit from such a tree that new inspiration came for inquiry into the nature of things," reads a verse from "The Good Book's" first chapter.

"When Newton sat in his garden, and saw what no one had seen before: that an apple draws the earth to itself, and the earth the apple," the verse continues, "Through a mutual force of nature that holds all things, from the planets to the stars, in unifying embrace."

The book's final chapter features a secular humanist version of the Ten Commandments: "Love well, seek the good in all things, harm no others, think for yourself, take responsibility, respect nature, do your utmost, be informed, be kind, be courageous: at least, sincerely try."

Grayling, reached Friday at a New York hotel just as he began his U.S. book tour, has been dubbed by some a “velvet atheist” or an “acceptable face of atheism,” he says, in contrast to more stridently anti-religious writers like Christopher Hitchens and Richard Dawkins, both of whom he counts as friends.

In other contexts, Grayling - who will soon take over as president of the British Humanist Association - admits he’s written critically about religion. But not in "The Good Book."

“It’s not part of a quarrel,” he says of his latest work. “It’s a modest offering… another contribution to the conversation that mankind must have with itself,” and one he says he wrote for everyone, Bible lovers included.

Given where society is today, inviting that conversation is all the more important, he says.

More than 16% of Americans say they are unaffiliated religiously, according to the Pew Forum on Religion and Public Life. Even so, Grayling says the hunger for a spiritual connection continues. That yearning, he argues , can be satisfied for many by taking a walk in the country, curling up with a beautiful book of poetry or even in falling in love.

“In all different ways, we can celebrate the good in the world,” he says.

While many intellectual traditions – religious and otherwise – teach that there’s “one right way to live,” Grayling says he hopes “The Good Book” will encourage people to “go beyond your teachers, your text” to understand that “we have to respect and relate to one another.”

Early sales indicate that people are open to what this new "Bible" teaches. On Monday, Grayling’s book was number 41 on Amazon’s UK bestseller list and number 1 in the philosophy and spirituality categories.