The idea of living in interesting times said to be a Chinese curse; in Leonardo da Vinci’s case, it was nothing short of a blessing. This latest portrait of the master (Simon & Schuster US; $49.99) is by Walter Isaacson, who has also written biographies of Benjamin Franklin, Albert Einstein and Steve Jobs. It is a quartet not brought together by mere coincidence.

“His ability to combine art, science, technology, the humanities, and imagination remains an enduring recipe for creativity,” Isaacson writes. “So, too, was his ease at being a bit of a misfit: illegitimate, gay, vegetarian, left-handed, easily distracted and at times heretical.”

He was born in 1452 just outside of Florence, a city of artists and artisans that nurtured his obvious gifts. Bastards like Leonardo were frequently incorporated into official family life, and the young man grew up in a rare 40-year period of peace between the febrile Italian city-states. Leonardo was openly a Florenzer, as the German slang of day described homosexuals, but collision with the morality police had the good fortune of occurring with a Medici. He lived out his life with his younger companion known as Salai, “Little Devil”.

In Isaacson’s digestion of the artist’s 7200 pages of notebooks, “the greatest record of curiosity ever created”, Leonardo’s charm dances on the page with the thought of his conception. “If the intercourse is done with great love and desire on both sides,” he wrote, “the child will be of great intellect, witty, lively, and lovable.”

His notebooks appear to have recorded his every thought. “Why is the fish in the water swifter than the bird in the air when it ought to be the contrary since the water is heavier and thicker than the air?” Leonardo mused among notes of personal anguish, mathematical blueprints, sketches and shopping lists. Also included: “Go every Saturday to the hot bath where you will see naked men.”

Isaacson’s portrait is at times overwrought, more TED Talk than Robert Caro, but he understands his job to illuminate a great man, not to attempt to outshine him. And Leonardo has a formidable track record in making others feel humble: his teacher Verrocchio is said to have “resolved never again to touch a brush” after seeing him begin to paint in earnest.

An obsessive observer of drapery from his youth, he became a pioneer of sfumato, instructing that one should “paint so that a smoky finish can be seen, rather than contours and profiles that are distinct and crude”, and chiaroscuro, contrasting light and shade through black pigment and conveying what Isaacson calls“the perfect glint of lustre”.

At 30, Leonardo moved to Milan and sent a letter to the city’s extravagant leader, Ludovico Sforza, in which he outlined 10 skills he could offer. These centred on machines of war, city design and architecture. As an afterthought, Leonardo wrote that “in painting, I can do everything possible, as well as any other man”.

This footnote of humility may have expressed his defining trait, a perfectionism that both contributed to his genius and hindered his output. A lifetime studying nature, anatomy and optics fed into Leonardo’s pantheistic relationship with the world, yet his paintings were firmly works of humanism. For all of the shadows that moved like smoke, the azure tints to flesh at dusk, Leonardo’s notes showed him to be a deep psychological thinker who cared about portraying the emotional state of his subjects. The origin is uncertain, but he may have coined the phrase that eyes are the window to the soul.

Whether or not it was our man, what do we see when we peer back into his? An inquiry so far removed from its subject stumbles somewhat to focus on his faults. Isaacson says he “was a genius undisciplined by diligence” and “more easily distracted by the future than he was focused on the present”. Leonardo has, at best, 15 completed pictures attributed to him. But to say he wasn’t conscientious is unfair: this incredible polymath was so diligent in everything he did that his quest for perfection could not be satiated.

It has been said that Leonardo was centuries ahead of his time, but in fact he was a man entirely of his own. Neither his father’s complicated contracts nor powerful patrons could compel him to finish many of his works. Modern technology has shown that he returned to some paintings decades later to improve on the anatomy that so intrigued him. One such favourite, the neck of a straining man, was a constant in his notebooks.

Isaacson builds this study of crippling perfection and emotional perception to its obvious crescendo. Leonardo doted on a portrait of a silk merchant’s young wife for 16 years, carrying her around Europe by mules until she eventually watched over him on his deathbed. Mona Lisa was his obsession. He turned down opportunities to paint wealthy and powerful, partially due to his friendship with the silk merchant, but largely, Isaacson believes, because the couple’s relative obscurity gave Leonardo licence to do as he pleased: the painting was always his.

She is a lifetime of observing the optics of light. She is the inquiring mind who pulled back the flesh of the lips of scores of cadavers to see how the muscles worked. She is the compassionate friend who hired troupes to entertain the subject to perfect that distinct leftward curl of the mouth into the most famous smile ever known.

Elle Hardy

Elle Hardy is an Australian journalist based in the United States. She can be found at www.ellehardy.com.