One of our recently acquired books is a volume from the Irish Heritage Series. Written by Laurence J. Flynn, it describes the pilgrimage site known as St Patrick's Purgatory, on Lough Derg in County Donegal.
A Lough Derg motif has been running through library events in the first half of 2010, as we had a lecture on the topic in May from Professor Jean-Michel Picard of University College Dublin, and also organised an exhibition with displays of maps, guidebooks, histories, illustrations and literary references to the site.
Lough Derg, with its cave, exemplifies the medieval conception of purgatory as a physical place, rather than merely the "state" of church teaching. According to medievalist Jacques Le Goff, this emphasis on "place" rather than "state" occured between 1170 and 1200. Le Goff calls the development "the birth of purgatory". The cave known as St Patrick's Purgatory is one of the oldest of these sites, and its location on an island in the middle of a lake illustrates the medieval motif of water (whether lake, river, or well) constituting a border between this world and the spiritual world, allowing passage from one to the other.
Professor Picard, during his talk, discussed the wealth of medieval descriptions of the Lough Derg pilgrimage which were produced throughout Europe. These include Hugh of Saltry's Tractatus de Purgatorio Sancti Patricii (The Legend of St Patrick's Purgatory), written in 1184. Hugh described a pilgrimage of thirty days, undertaken once the authorities on the island had made clear the trials to be undergone. The pilgrim would fast for fifteen days, after which he would attend Mass and receive communion. He would then be lead to the entrace of the purgatorial cave, and warned of the devils and other dangers to be faced. If his resolve held, Benediction would be said, the pilgrim would enter the cave, and the door would be bolted after him. He would expect to see visions of the otherworld, of the pains of purgatory and the joys of heaven. Once released from the cave the next morning, the pilgrim spent another fifteen days on the island, and thus completed his pilgrimage.
The modern pilgrimage is, of course, very different, and information on this can be found at http://www.loughderg.org But the medieval belief that Purgatory had "a local habitation and a name", where the worlds of human experience, temporal and spiritual, could intersect, continues surely to resonate.