The Mona Lisa Foundation

The Challenges of a Leonardo Attribution

Few works of art have garnered as much attention from experts and the public as the ‘Mona Lisa’ in the Louvre Museum. By contrast, the ‘Earlier Mona Lisa’ has spent much of its existence hidden from view. Despite this, on the few occasions the painting has been available to be viewed, significant expert opinion has been recorded.

It is probably fair to say that attributing a painting to Leonardo da Vinci with certainty is one of the most difficult tasks in the field of Old Master paintings. To date there are about 18 to 20 paintings “more or less” attributed to Leonardo. One states “more or less” since there is not even one painting about which all the recognized Da Vinci experts agree. It is even disputed that some parts of the famous ‘Mona Lisa’ portrait in the Louvre are not by the master. One famous expert said that attributing a painting to Leonardo is like “holding in one’s hand a burning iron rod.”

Nonetheless, it is generally accepted that he did paint all or at least the essential parts of those paintings currently attributed to him. In the case of a Da Vinci portrait, an attribution is generally agreed upon if the artist painted only the face, while some experts argue that it is even enough if Da Vinci had simply conceived the structure of the painting. It should be noted that some of his pupils and followers had great talent. The well-known ‘Lady with an Ermine’ and ‘La Belle Ferronière’ represent only recent attributions to Leonardo, having been attributed to pupils for almost 400 years.

Professor Jean-Pierre Isbouts says, “Every interpretation is subject to subsequent dispute. When you look at dating, when you look at authorship, when you look at provenance. So I think it’s just part of the world we live in that Leonardo scholarship happens to be a debating society whether you like it or not.

So what are the key elements that would indicate that a work is by Leonardo authorship?

Historical Evidence
The history must be right. Given that the attribution of the Louvre ‘Mona Lisa’ is beyond doubt, in order to consider a Leonardo attribution for the ‘Earlier Mona Lisa’, it is essential to first establish that Leonardo did, in fact, paint two Mona Lisas.

There should be evidence that Leonardo worked on such a painting or that it was recognised by art historians early on. For the ‘Earlier Mona Lisa’, there is a well-documented record of an unfinished portrait of a young Lisa with side columns commissioned by Mona Lisa’s husband, prior to his work on the version now in the Louvre.

The historical documentation, coupled with Leonardo’s later glazing technique used for the Louvre painting, the documented difference of two paintings and two different commissions, as well as his regular practice of performing multiple works on the same theme, strongly suggests that he did paint two works on the subject of Mona Lisa. In fact, in published opinions on the matter, 28 out of 29 experts believe this to be either possibly or certainly the case.

Science & Materials
The scientific results should not reveal any factor that would make the work inconsistent with Leonardo on the grounds of dating, pigments used or physical structure. As Lumiere Technology’s Pascal Cotte states, all tests on the ‘Earlier Mona Lisa’ show that it conforms.

Though few works attributed to Leonardo are on canvas, it should be noted that some experts believe as any as half of Leonardo’s works are lost or missing, many of which may have been painted on this support. Additionally, by the early 1500s – the purported date of execution of the ‘Earlier Mona Lisa’ – Leonardo had over 30 years of experience of working with fabric supports. Examples of such work can be seen in his early drapery studies. It is also well known that Da Vinci was an eternal experimenter and innovator, and it should therefore come as no surprise that he tried his hand on this material. Perhaps most importantly, Leonardo devoted an entire section to painting on canvas in his Treatise On Painting and we know that everything he recorded came from his personal experience, so it is obvious that he must have experimented with painting on canvas.

The results of extensive scientific analyses of the painting materials and the canvas support, all suggest that they were indeed available to Leonardo in the early 1500s.

Comparative Examination
It is necessary to determine whether the ‘Earlier Mona Lisa’ displays the hallmarks of the great master.

Though this in itself does not establish an attribution, it is necessary to verify that it is an original work and not simply a copy of the painting in the Louvre. Though the two Mona Lisa paintings are similar there are important differences, for example their overall compositions, their backgrounds, the sitting angles of the subjects, the apparent age of the subjects, the sizes and materials of their supports, the flanking columns, the embroideries, as well as other aspects. In addition, analysis of the ‘Earlier Mona Lisa’ has revealed underdrawings and the painting has extra detail in its lower section. All of this indicates that it is an original work and, in the words of the much respected art critic Paul Konody, “It is in no sense of the word a ‘copy’, but varies in important points from the Paris ‘Mona Lisa’.”

We must look at the painting as would an experienced connoisseur who can identify Da Vinci’s style and characteristics. We have already examined the statements by the experts of the 1920s. Most of today’s experts and historians share that same level of enthusiasm towards the ‘Earlier Mona Lisa’. As Isbouts reflects: “ … she glows. And all the pink tones and hues that Giorgio Vasari writes about are patently visible … That wonderful chiaroscuro, that interplay of light and shadow … there simply isn’t any other artist who could have created it.

Professor Atila Soares agrees: “ … the face, the hands … the whole atmosphere of the painting … you don’t see that in other versions or paintings that copy Da Vinci.

Admiring the complexity and customization of the geometric proportions, Alfonso Rubino believes that it could not have been painted by another person: “Given the date of the first commission, if the ‘Earlier Mona Lisa’ is false, then all the works of Leonardo are false.

Professor Alessandro Vezzosi, arguably the most credible authority on the subject of Mona Lisa today, declared “Finally, when I got to see the original, even more than the emotion, I found a character that was inviting me to a dialogue with her gaze and with that certain smile …

View of the Experts
The latest survey of all known published opinions reveals that currently 24 experts believe that Leonardo possibly (p) or certainly (c) painted the ‘Earlier Mona Lisa’. In chronological order of the published opinion they are: Hugh Blaker (c), Paul Konody (c), John R. Eyre (c), Giulio Cantalamessa (p), Commendatore Cecconi (c), Arduino Colossanti (c), Commendatore Marini (c), Anto Sciortino (p), Cesare Segre (c), Ludovico Spiridon (c), San Martino di Valperga (c), Adolfo Venturi (c), R.H. Wilenski (p), A.C. Chappelow (c), Henry F. Puliitzer (c), Kenneth Clark (p), John F. Asmus (c), Pascal Cotte (p), Carlo Pedretti (p), Alfonso Rubino (c), Atila Soares (c), Alessandro Vezzosi (p), Jean Pierre Isbouts (c), Albert Sauteur (c).

However, 4 experts (Martin Kemp, Mauro Natale, Frank Zoellner and Luke Syson) have gone on record to deny a Leonardo attribution to the ‘Earlier Mona Lisa’. Despite in some cases repeated invitations presented by the foundation to view the painting, they have declined such invitations, even though one of them has stated how important it is to see a painting “in the flesh” before giving any serious opinion about it.

The opinion of these experts is unfortunately therefore only based on reproduced images and clearly, from what has been recorded of these opinions, also perhaps given without considering the wealth of evidence and the new findings that have come to light in recent years. The main objections raised are as follows:

1. “Leonardo would not have painted in canvas.”
This point has been treated in great detail. See

2. “There is no evidence that Leonardo painted two Mona Lisas.”
The historical evidence concerning the two distinctly separate paintings is preponderant as has been abundantly described throughout this website. There can be no more logical and plausible explanation given what is now known regarding the historical facts.

3. “The ‘Earlier Mona Lisa’ is a copy.”
Among other factors, given the numerous differences between the earlier and Louvre Mona Lisas and the autograph characteristics found on both paintings, [see above], this line of argumentation does not hold.

4. “The face looks too good.”
A criticism is that it is of such exquisite quality that it has been suggested that it may have been recently painted. The extensive scientific evidence, including reports relating to overall condition, dating, pigment and spectral analyses demonstrate that this is impossible.

5. “The painting does not “look” like a Leonardo work.”
It is obvious that when one first looks at reproduced images of the ‘Earlier Mona Lisa’ painting as a whole, one can recognize the inferior quality of the background and perhaps parts of the dress, and one may find the cluster of trees to the left without its natural reflection in a lake (that is shown in the Oslo Museum copy) somewhat disturbing.

However, given Leonardo’s practice of delegating less important section of his works to assistants and of leaving his works unfinished, this in no way negates a Leonardo attribution. More importantly, all experts who have seen the painting confirm that no reproduced image, digital or otherwise can replace a personal examination which reveals the exquisite flesh tones and brilliant play of light and shadow in the face and hands, besides the captivating look and beautiful smile that one can only experience when viewing the painting itself. In view of this, it would appear that these four experts may have expressed their opinion without careful consideration and examination of the evidence available.

Latest Scientific Developments

Until now, it has been believed that science cannot determine an attribution. However, new technologies are now enabling us to make strides in all fields and art is not being left behind.

Just as he was a key pioneer in developing the field of spectral imaging, Prof. John Asmus is now pioneering new ways to present ‘hard evidence’ for attribution. He has found that artists have unique brushstroke techniques, particularly in their treatment of light and shadow. He developed a scientific method, which is today peer-reviewed and approved, that measures these brushstrokes by analyzing the histogram distribution of billions of pixels obtained from a multispectral digitisation of a painting. It has worked perfectly for confirming Rembrandt originals and, together with several collaborators, he is now developing the same research and results for Leonardo paintings. Having applied his technique to the Mona Lisas, he concludes: “I would say that it’s 99% certain that the two Mona Lisas were done by the same artist.”

This conclusion is of vital importance in itself as it implies that denying a Leonardo attribution to the ‘Earlier Mona Lisa’ is equivalent to denying the same attribution to the painting of the Louvre.

In conclusion, when it comes to a great international icon such as the Mona Lisa, there will always be resistance by at least some experts who deem a Leonardo attribution just too difficult to accept. These experts sometimes ignore facts and seize on insignificant and superfluous details to fuel their opposition, to preserve the traditional line and not to risk jeopardising their reputation.

In the words of Professor Asmus: “As to whether people who will refuse to accept the contention that the ‘Earlier Mona Lisa’ is by Leonardo or not, my experience is there will always be people who will object to a theory like that. There are still people around who object to the spherical earth who maintain that it’s a flat earth.”

The Mona Lisa Foundation is determined to present the facts, opinions and documents concerning this most fascinating of works around the world, through publications, films and, most important of all, public exhibitions of the painting itself. Though it may possibly take years, the foundation is confident once presented, the facts will pervade into all realms of connoisseurship, leading to universal acceptance of this great masterpiece as the ‘Earlier Mona Lisa’ by Leonardo da Vinci.