Indeed, the book at points reads almost like an enthusiast’s attempt to catalogue everything Leonardo ever did.

Rather, his solution to the biographer’s problem is simple: to focus almost entirely on Leonardo’s works. To his credit, Isaacson for the most part resists such urges. The most excitable of them – and there have been many – have taken the lack of relevant evidence as a licence to give free rein to their most fanciful psychoanalytical or esoteric instincts, whether concerning Leonardo’s status as an illegitimate child, his homosexuality or the supposed clues he left us in his paintings. How can the biographer get past this impasse? Indeed, even the most eminent Leonardo scholars admit that our knowledge of such basic questions as the chronology of the composition of the paintings (including the Mona Lisa) remains limited. But while these reveal a great deal about his phenomenally wide-ranging interests, they do not offer much for the biographer looking for psychological or personal insights. Leonardo famously kept copious notebooks, replete with beautiful diagrams and notes in his left-handed mirror writing, and we are fortunate that a sizeable portion of them has survived. There, he had access to vast amounts of personal documents (and, in the case of Jobs, to scores of interviews with him and those who knew him). In one way, however, the situation here is rather different from Isaacson’s previous biographies. Now he has turned his hand to Leonardo himself, for whose boundless curiosity he has an infectious reverence and passion. The fear of becoming a modern Vasari has never fazed Walter Isaacson, former chairman of CNN and managing editor of Time magazine, who has written biographies of Steve Jobs, Albert Einstein and Benjamin Franklin, among others.

It is not difficult to draw a direct line from Vasari’s celebration of such ‘divine’ artists to the stratospheric sums paid for their works, epitomised by the recent sale for $450m of a painting (possibly) by Leonardo, Salvator Mundi. The locus classicus for such hagiography is the treatment of Raphael, Leonardo da Vinci and Michelangelo in Giorgio Vasari’s Lives of the Artists (1550). The danger of producing hagiography is all too real, and all too familiar in the history of the genre. If writing a biography is difficult, writing a biography of someone deemed a ‘genius’ is positively perilous.

Leonardo da vinci book isaacson