The detail that unlocks the Mona Lisa

The 1503 painting by Leonardo da Vinci is the world's most famous piece of art. Kelly Grovier explores an overlooked object that offers a different perspective on the masterpiece.

Some things are so obvious you never really notice them. Take, for instance, the way the white space between the "E" and the "x" in the FedEx logo forms a big white arrow pointing forward. We've seen the sign whizz past us countless times without ever clocking its subliminal point. Another ubiquitous cultural image is the Mona Lisa. Leonardo da Vinci's inexhaustible portrait of Lisa del Giocondo, the 24-year-old mother of five and wife of a wealthy Florentine silk merchant who sat for the High Renaissance master in 1503, is doubtless the most famous work of art in the world. Yet how many of us have ever consciously noted the object in the painting that is closer to us than any other – the chair on which the mysterious woman sits? Never mind that the piece of furniture is the only thing that Leonardo's sitter grips in her hand (she's literally pointing at it with every finger she has), the chair must surely be the single most neglected aspect of the otherwise over-stared-at icon. Hiding in plain sight, it may also be the arrow that points the way to the work's deepest meanings.

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For centuries, our attention has largely been focused elsewhere in the small (77 x 53cm/30 x 21in) oil-on-poplar panel, which Da Vinci never fully finished and is thought to have continued to tinker with obsessively until his death in 1519 – as if the painting's endless emergence were the work itself. A preoccupation principally with Mona Lisa's inscrutable smile is almost as old as the painting, and dates back at least to the reaction of the legendary Renaissance writer and historian Giorgio Vasari, who was born a few years after Da Vinci began work on the likeness. "The mouth with its opening and with its ends united by the red of the lips to the flesh-tints of the face," Vasari observed in his celebrated Lives of the Most Excellent Painters, Sculptors, and Architects, "seemed, in truth, to be not colours but flesh. In the pit of the throat, if one gazed upon it intently, could be seen the beating of the pulse." He concluded: "In this work of Leonardo, there was a smile so pleasing, that it was a thing more divine than human to behold, and it was held to be something marvellous, in that it was not other than alive."

The mesmerising mystery of Mona Lisa's smile and how Leonardo magically leveraged it into creating "a thing more divine than human" and yet "not other than alive" would prove too intense for many to bear. The 19th-Century French art critic Alfred Dumesnil confessed to finding the painting's paradox utterly paralysing. In 1854 he asserted that the subject's "smile is full of attraction, but it is the treacherous attraction of a sick soul that renders sickness. This so soft a look, but avid like the sea, devours". If legend is to be believed, the "treacherous attraction" of Mona Lisa's irresolvable smirk consumed too the soul of an aspiring French artist by the name of Luc Maspero. According to popular myth, Maspero, who allegedly ended his days by leaping from the window of his Paris hotel room, was driven to destructive distraction by the mute whispers of Mona Lisa's engrossingly gladsome lips. "For years I have grappled desperately with her smile," he is said to have written in the note he left behind. "I prefer to die."

Not everyone, however, has been content to locate the centre of Mona Lisa's magnetising mystique in her enigmatic grin. The Victorian writer Walter Pater believed it was the "delicacy" with which her hands and eyelids are rendered that transfix and hypnotise us into believing that the work possesses preternatural power. "We all know the face and hands of the figure," he observed in an article on Da Vinci in 1869, "in that circle of fantastic rocks, as in some faint light under sea". Pater proceeds to meditate on the Mona Lisa in such a singularly intense way that in 1936 the Irish poet William Butler Yeats found himself compelled to seize a sentence from Pater's description, break it up into free-verse lines, and install them as the opening poem in the Oxford Book of Modern Verse, which Yeats was then compiling. The passage that Yeats couldn't help co-opting begins: "She is older than the rocks among which she sits; like the vampire, she has been dead many times, and learned the secrets of the grave; and has been a diver in deep seas, and keeps their fallen day about her; and trafficked for strange webs with Eastern merchants, and, as Leda, was the mother of Helen of Troy, and, as Saint Anne, the mother of Mary; and all this has been to her but as the sound of lyres and flutes." The portrait "lives", Pater concludes, "only in the delicacy with which it has moulded the changing lineaments, and tinged the eyelids and the hands".

Pater's description still astounds. Unlike Dumesnil and the doomed Maspero before him, Pater sees past the seductive snare of the portrait's smile to a larger vitality that percolates as if from deep below the surface. Contending that the painting depicts a figure suspended in ceaseless shuttle between the here-and-now and some otherworldly realm that lies beyond, Pater pinpoints the mystical essence of the panel's perennial appeal: its surreal sense of eternal flux. Like Vasari, Pater bears witness to a breathing and pulsing presence – "changing lineaments" – that transcends the inert materiality of the portrait's making. Key to the force of Pater's language is an insistence on aquatic imagery that reinforces the fluidity of the sitter's elusive self ("faint light under the sea", "a diver in deep seas", and "trafficked… with Eastern merchants"), as if Mona Lisa were an ever-flowing fountain of living water – an interminable ripple in the endless eddies of time.

Perhaps she is. There is reason to think that such a reading, which sees the sitter as a shape-shifting spring of eternal resurgence, is precisely what Leonardo intended. Flanked on either side by bodies of flowing water that the artist has ingeniously positioned in such a way as to suggest that they are aspects of his sitter's very being, Da Vinci's subject has a strangely submarine quality to her that is accentuated by the algae green dress she wears – an amphibious second skin that has only grown murkier and darker with time. Pivoting her stare slightly to her left to meet ours, Mona Lisa is poised upon not just any old bench or stool, but a deep-seated perch known popularly as a pozzetto chair. Meaning "little well", the pozzetto introduces a subtle symbolism into the narrative that is as revealing as it is unexpected.

Suddenly, the waters we see meandering with a mazy motion behind Mona Lisa (whether belonging to an actual landscape, such as the valley of the Italian River Arno, as some historians believe, or entirely imaginary, as others contend) are no longer distant and disconnected from the sitter, but are an essential resource that sustain her existence. They literally flow into her. By situating Mona Lisa inside a "little well", Da Vinci transforms her into an ever-fluctuating dimension of the physical universe she occupies. Art historian and leading Da Vinci expert Martin Kemp has likewise detected a fundamental connection between Mona Lisa's depiction and the geology of the world she inhabits. "The artist was not literally portraying the prehistoric or future Arno," Kemp asserts in his study Leonardo: 100 Milestones (2019), "but was shaping Lisa's landscape on the basis of what he had learned about change in the 'body of the Earth', to stand alongside the implicit transformations in the body of the woman as a 'lesser world' or microcosm." Mona Lisa isn't sitting before a landscape. She is the landscape.

Drawing from a well

As with all visual symbols employed by Leonardo, the pozzetto chair is multivalent and serves more than merely to link Mona Lisa with the artist's well-known fascination with the hydrological forces that shape the Earth. The subtle insinuation of a "little well" in the painting as the very channel through which Mona Lisa emerges into consciousness repositions the painting entirely in cultural discourse. No longer is this a straightforwardly secular portrait but something spiritually more complex. Portrayals of women "at the well" are a staple throughout Western art history. Old Testament stories of Eliezar meeting Rebekah at a well and of Jacob meeting Rachel at the well went on to become especially popular in the 17th, 18th, and 19th Centuries, as everyone from Bartolomé Esteban Murillo to Giovanni Antonio Pellegrini, Giovanni Battista Tiepolo to William Holman Hunt tried their hand at one or other of the narratives.

Moreover apocryphal depictions of the New Testament Annunciation (the moment when the Archangel Gabriel informs the Virgin Mary that she will give birth to Christ) as occurring at the site of a spring were a mainstay among Medieval manuscript illustrators, and may even have inspired the oldest surviving visual portrayal of Mary. An endlessly elastic emblem, as Walter Pater intimated, Mona Lisa is doubtless capable of absorbing all such reflected resonances and many more besides. There is no one she isn't.

But perhaps the most pertinent parallel between Da Vinci's Mona Lisa and pictorial precursors is one that can be drawn with the many representations of a biblical episode in which Jesus finds himself at a well, engaged in cryptic conversation with a woman from Samaria. In the Gospel of John, Jesus makes a distinction between the water that can be drawn from the natural spring – water which will inevitably leave one "thirsty" – and the "living water" that he can provide. Where water from a well can only sustain a perishable body, 'living water' is capable of quenching the eternal spirit. Notable depictions of the scene by the Medieval Italian painter Duccio di Buoninsegna and by the German Renaissance master Lucas Cranach the Elder tend to seat Jesus directly on the wall of the well, suggesting his dominion over the fleeting elements of this world. By placing his female sitter notionally inside the well, however, Da Vinci confounds the tradition, and suggests instead a merging of material and spiritual realms – a blurring of the here and hereafter – into a shared plane of eternal emergence. In Da Vinci's enthralling narrative, Mona Lisa is herself a miraculous surge of "living water", serenely content in the knowledge of her own raging infinitude.

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