A few weeks ago I went along after work to the Velazquez exhibition at the National Gallery (which very helpfully opens late on Wednesdays).

In the 17th century, Velazquez was chosen by Philip IV of Spain to be his official court painter, so I knew the exhibition would be full of royal and aristocratic portraits. However, amongst the paintings of the finely-attired, richly-adorned upper echelons of Spanish society, there was one which caught my eye.

This was a portrait from the 1630s of a young man called Francisco Lezcano who was employed as an entertainer to the royal family. What made this painting leap out at me was the fact that Lezcano was a person of short stature – more commonly known as a dwarf. Apparently, many of the entertainers at the Spanish court were physically or mentally disabled. Lezcano’s particular role was to provide entertainment for Philip IV’s son and heir, Prince Baltasar Carlos.

Velazquez depicts Lezcano sitting on a stool, holding a pack of playing cards in his hands. Although his head is tilted slightly backwards, he is gazing directly at the viewer. He wears plain and simple clothes but they are well-kept and of a respectable quality – they are certainly not rags. He has a charming face, smooth skin, neat hair and he seems to be on the point of smiling. One of his short legs projects straight out in front of him while the other hangs down casually towards the floor.

According to the guide book, the lack of a glint in Lezcano’s eyes indicates that he had learning difficulties. To be honest, I have my doubts about this theory. I don’t think it’s possible to deduce a person’s mental abilities from their appearance. However, as there could well be some other historical source which justifies the assertion that Lezcano’s mind was impaired, I will assume that the guide book is correct and that Lezcano was indeed learning disabled. (Besides which, it would be rather impertinent of me to claim to know more about this painting than the art historian who wrote the guide book).

The most remarkable and important thing about this portrait is that it exists at all. Velazquez clearly regarded Lezcano as worthy of being painted when he could easily have ignored him and stuck to painting those wealthy nobles, those privileged princes, those heavily-bejeweled princesses.

Instead, Velazquez painted Lezcano with the same care and attention to detail as he did the paintings of the king, the artist applied his technical mastery, his intense observation and his commitment to realism, and all of his skills are on display in this painting.

Moreover, Velazquez paints Lezcano without any hint of prejudice. Velazquez does not portray him with pity or contempt. He does not suggest he should be a figure of fun or ridicule. At the same time, he does not try to hide or gloss over Lezcano’s physical features. Velazquez seems entirely comfortable being with someone with a disability. As a result, more than 350 years later, we can see an honest and perceptive portrait of this man.

Lezcano’s purpose at court was to give amusement and, to our eyes, this sounds degrading and demeaning (with its unpleasant connotations of later disability ‘freak shows’). But what’s interesting is that in 17th century Spain, people with learning disabilities were not looked down upon, they were actually revered. In the highly charged religious atmosphere of Velazquez’s day, individuals like Lezcano were regarded as being especially close to God. They were allowed to behave almost as they wanted and given a level of freedom that not even the court’s aristocrats enjoyed.

Maybe we in the 21st century, who pride ourselves on our anti-discrimination legislation and our equal opportunities policies, could learn a lesson from Velazquez. Now, don’t misunderstand me. I’m not suggesting for one minute that disabled people should again be venerated. (If someone tried to turn me into an object of veneration, there would be two consequences. Firstly, I would run the person over very, very painfully. And secondly, my friends would kill themselves laughing.) But we ought to be more aware that, while many people with learning disabilities today have a decent quality of life, there are others who would envy Lezcano.

In January a report by the Healthcare Commission severely criticised a primary care trust in London for “institutional abuse” of people with learning disabilities. It found “impoverished and completely unsatisfactory” living conditions with some residents staying in cramped rooms and only having access to three or four hours of activity a week.

People were fed too quickly to enjoy their food, were not supported to become independent and staff communicated poorly. The review was prompted by a number of serious incidents including allegations of physical and sexual abuse. One member of staff was sentenced to six years in prison for sexual activity with a woman who did not have the mental capacity to give consent.

This report was the second into neglect of people with learning disabilities within the space of six months. The Healthcare Commission is so concerned about the quality of care for people with learning disabilities that it is now carrying out a national audit of 200 NHS and private services in England to check on standards.

Even when people with learning disabilities are not being neglected and abused, they are sometimes denied the chance to develop their full potential. According to the Disability Rights Commission, only 17% of people with learning disabilities are in paid employment. Obviously, there are people with learning disabilities who will never be capable of working. But a significant proportion of them could if they were given appropriate support and employers were more open-minded and imaginative.

When I look at Francisco Lezcano’s portrait, I see a young man whom Velazquez treated with dignity and respect. More than 350 years later, our society needs to follow Velazquez’s example and also treat people with learning disabilities with dignity and respect.

I’m afraid the Velazquez exhibition at the National Gallery has now finished. But next time you find yourself in Madrid, I suggest you pop into the Prado where the painting of Lezcano is permanently displayed. It’s vastly superior to the Mona Lisa any day…