Creativity. Imagination. Mystery. Those are the watchwords of Walter Isaacson’s new biography, “Leonardo da Vinci,” the most recent in his studies of such well-known men of genius as Benjamin Franklin, Albert Einstein and Steve Jobs.

No one doubts Leonardo was a genius in art and in science, and his was a life of creativity that ripples into the present. But what captivated this best-selling biographer to lead him to devote years to researching Leonardo’s life as a Renaissance man?

“It was the moment I saw Leonardo’s notebooks,” Isaacson said. “Most people who’ve written about Leonardo are art critics, so they base their work on 12 or so great masterpieces. But there are more than 7,000 pages of notebooks — all over the place, even in Windsor Castle, even in Bill Gates’ house. And you look at those pages, and you see a mind dancing with nature, dancing with imagination.”

Paper was expensive then, so Leonardo crammed every inch with notes and sketches, as readers can see in this lavishly illustrated volume. “It reminded me that paper was a really great technology,” Isaacson said, recalling a former struggle to find Steve Jobs’ old emails. “Five hundred years after Leonardo’s death, we can still look at the same paper he wrote on.”

Isaacson speaks of his subject with affection, urgency, admiration, awe. “The great thing about writing about Leonardo today is that there’s so much more to discover — for example how, with technology, we can look at each brush stroke he put on the Mona Lisa,” he said.

“We know he dissected the human eye to see how the center part of the retina sees detail and the edges of the retina see shadows. That’s how he made the Mona Lisa’s smile flicker on and off. If you’re looking directly at it, it looks like she’s not smiling much, but if your eye wanders to her cheek or to her chin, the shadows make it look as if she’s smiling more broadly.

“It helps to understand the science, the optics, the anatomy as well as the brush strokes, and that’s the lesson of Leonardo for our kids today, and for ourselves. Don’t say you only need to know engineering or coding or science. Or that if we’re a humanist or we love art, that you don’t ignore science. You’ve got to love the connection between all of the humanities and the sciences.”

That examination of the “Mona Lisa” is only one example of the painstaking detail and close attention Isaacson gives to his subject in this lavishly illustrated volume. He draws on everything from small sketches to great paintings, from letters to notebook pages. This biography even has one of the all-time great hymns of praise to the interesting to-do list.

“Leonardo made a list every few days of what he wanted to learn, and the lists are all in his notebooks and they’re fascinating. Weird things, like how do they walk on ice in Holland? What does the tongue of a woodpecker look like? Why is the sky blue? Why do fish move faster in water than birds in air because water is heavier? How would you draw emotions on the face? How do the lips work to show emotion? All these things he’s very curious about,” Isaacson said. “If we want to, every day, we can make ourselves 10 percent more observant and more curious about the world around us.

“We can pause for just a moment when we see a bird flying, and like Leonardo, we can wonder, when we see a bird fly, does he flap his wings faster up or down and what does that mean for how fast he flies?

“I’ve been duck hunting in southern Louisiana, and the next time I go, I’m going to look at that wing and see how the tips point, and I’m going to do that because I want to be, in just the tiniest of ways, a little bit like Leonardo.”

What’s the most interesting item on Isaacson’s to-do list these days? “Start teaching,” he says quickly.

After 14 years as head of The Aspen Institute, Isaacson will become a university professor of history at Tulane University this spring semester. “It’s a new challenge,” he said. “I’ll be teaching a course about the history of the digital revolution, from Ada Lovelace to Mark Zuckerberg. I think it’s exciting to study how innovation happens.’

He felt a longing for home after a distinguished career in all types of media, from The New Orleans Times-Picayune and The Sunday Times of London to CNN and Time  magazine. It's not surprising, because he’s a New Orleans guy through and through, growing up in Broadmoor, going to Isidore Newman School before leaving for Harvard, then to Oxford as a Rhodes Scholar. His brother still lives in the family home on Napoleon Avenue, while Isaacson and his wife, Cathy, have chosen French Quarter digs.

“Sure, some of us get the opportunity to go to Time magazine or work in Washington, but I began to feel it was time to come home to New Orleans. I found myself living there half time, and I was ready to be there more,” he said.

Watch for him to put some of his own fierce creative energy into our city, just as he did after Katrina with the Louisiana Recovery Authority and other initiatives.

And look for him to be perhaps a little more contemplative, a little more philosophical these days. That’s where the mystery comes in.

“That’s the final lesson in my book. Embrace mystery. If you’re going to be like Leonardo, you have to be curious, you have to be observant, and there are many other things you have to do. You have to not characterize things into silos or disciplines. But in the end the big lesson is embrace mystery. Because his great contribution to art and to science is what he calls sfumato, the lines that aren’t very sharp, but kind of blurry, as if it were smoke dissipating into the air. The really interesting thing is that blurred line between observation and imagination.”

Susan Larson hosts The Reading Life on WWNO.