We live in an age of instant images and memes, when 10,000 copies of a picture can be flung around the world in seconds by sliding a finger half an inch across a phone screen. This would have been unbelievable 20 years ago and impossible even to imagine 20 years before that. Go back 1,000 years, and it would have been sorcery. But it is in the world of hand-copied manuscripts 1,000 years old or more that the digital revolution has had some of its most profound and unambiguously beneficial effects. What may have taken three years to write out can today be printed out in three seconds. There are now tens of thousands of once unique documents which have been digitised and placed online for anyone to access all around the world, and this is a vast, democratising wonder.

Take, for example, the Parker Library in Corpus Christi College, Cambridge, which contains the scholarly plunder of monasteries dissolved under Henry VIII during the Reformation and collected by Archbishop Matthew Parker. It has been digitised in a project with Stanford University, and this year the site was opened to all comers to browse after 10 years behind scholarly paywalls. What is astonishing is not just the texts themselves, but the pictures: the illuminations on some of the manuscripts show off the fertility and vividness of the medieval imagination.

Digitised collections of these sorts cannot entirely substitute for real libraries. To touch with your own hand a parchment from a medieval monk is an experience no screen can offer, but it is one which must always be restricted to a lucky few. There are some things so old and fragile that even being looked at may damage them. The caves at Lascaux had to be closed to protect the paintings from the breath of tourists and replaced by a virtual display. Yet in some ways these copies are better than the originals. Reproductions of a high enough quality make obvious detail that’s invisible to the native eye: Twitter is full of astonishing collections of medieval marginalia, some drawn at a scale that makes them easily overlooked. What’s more, digital collections can be gathered on one screen from across the globe. The International Dunhuang Project reunites on screen tens of thousands of Buddhist scrolls and artefacts taken from an abandoned cave library in western China during the chaotic early years of the 20th century by western collectors. What is possible with this one collection should fairly soon be possible with all the scholarly digitised manuscripts of the world. The hope is to bring them under one system of classification so that they can quickly be searched and sorted no matter where they came from and where they now are stored.

The world may always prefer cat gifs to codices, but the translation from parchment to pixels reminds us of the humanistic optimism with which the web came into the world, and shows that much of it was not misplaced at all.