Above the entrance to St Gallen Abbey Library, one of the oldest of its kind, is a Greek inscription which translates into English as "pharmacy of the soul".
The monks who founded the library considered books as medicine for the spirit. The 150,000 strong collection, now part of a Unesco World Heritage site, continues to inspire visitors and scholars today.
On entering the library, the visitor is immediately struck by two things – the vast quantity of books and the beauty of the room.
Remodelled in the 18th century, using the monastery's own craftsmen, the library is a heady mix of rich woodwork, ceiling paintings and stucco. The whole room – even on a rainy day - is illuminated by light from 34 windows.
It is said to be one of the most beautiful Baroque libraries in existence.
But only 30,000 of the library's collection – books and manuscripts – can be seen. Some volumes are considered simply too precious to be shown in public.
"There are 400 books here that are more than 1,000 years old," Karl Schmuki, the library's deputy director, told swissinfo.ch.
Ancient treasures include a Latin manuscript of the Gospel and the oldest book in German.
The library also contains the earliest known architectural drawn on parchment - of the abbey itself - a copy of which can be seen in the library.
Glass cases hold fine illuminated manuscripts, some of which were done in the monastery.
The library was founded in 719 and is almost as ancient as the whole abbey site, which can traces it origins to a hermitage set up by Irish monk Gallus.
By the 9th century – the start of the abbey's golden age – the library had already built up a notable collection of books, including works from antiquity.
"St Gallen became rich through bequests of land and property and became very active in the realm of the sciences. Books were written and studied here," said Schmuki.
The monastery became one of the most important north of the Alps, he added, with its influence – and reputation as a place of learning - extending into the German kingdom.
After a difficult time during the Reformation – St Gallen became the second Swiss city to turn to Protestantism – the abbey underwent a revival in fortunes in the 18th century when the library was remodelled.
But the jubilation did not last long. In 1798, French soldiers, fresh from the Revolution which toppled France's monarchy, marched though the area and attacked the buildings.
The monks fled, but not before they had taken the library's precious collection of books to safety.
A further blow came in 1805 when the newly formed Canton of St Gallen, eager to end the abbey's considerable influence, decided to dissolve the monastery. No monks have lived at the site since.
It was, however, decided to preserve the library. The whole abbey area, which also contains a magnificent Baroque church, now the cathedral, as well as medieval buildings, became a World Heritage site in 1983.
The collection of books and manuscripts now attracts more than 100,000 visitors a year from all over the world – more than all of St Gallen's other museums together, says Schmuki.
The library also functions as an academic institution for scholars of German and old Irish, as its collection of early medieval Irish manuscripts is said to contain more texts than in Dublin.
So it would seem that the library is still acting as a "pharmacy for the soul", offering up some medicine and support for the human spirit, just as the monks had intended.
"Where our offices now stand used to be the monks' sickrooms," Schmuki explained. "And when you're ill you usually get some kind of medicine."
"Books are a kind of medicine for the soul, you can read a book and you might be so fascinated that you can forget all your problems," he said.
Isobel Leybold-Johnson in St Gallen, swissinfo.ch
612: Irish monk Gallus builds hermitage in Steinach valley
719: First stone church and library built
9/12th century: Golden age of monastery
14/15th century: Rise of linen industry, Reformation. City gains independence
1755: Rebuilding of Abbey church and library begins
1798: Helvetian Revolution overthrows old order, including monastery state
1803: St Gallen canton established, dissolves monastery in 1805
1824: Abbey church becomes cathedral, diocese founded in 1847
1983: Unesco World Heritage site
Unesco calls the abbey site "a perfect example of a great Carolingian monastery" and one of the most important in Europe from the 8th century until 1805.
It says the library and the cathedral form its centrepiece, says Unesco, reflecting "12 centuries of continuous activity".
The cathedral has been described as one of the last monumental Baroque monastery buildings of the western world. It was completed in 1766.
Its interior is surprisingly light for such a huge building, with pale green stuccowork and many rich frescos on the ceiling.
The wood and stone of the floor level is supposed to represent earth and the ceiling paradise. The pillars remain largely undecorated so as to draw the eye up heavenwards.