When the anthropologist arrives, so the saying goes, the gods depart. Science, in explaining myths, strips away magic. There are places, though, with more resistance than others, places where the magic can still be felt. Among them are the west coasts of Ireland and Scotland, which English travel writer Philip Marsden explores from the sea in his marvellous new book, The Summer Isles.
Here, he says, is a region whose gritty topography and fractured shorelines have "helped generate the wilder projections of outsiders and inhabitants alike: phantom islands from beyond its headlands, otherworld from beneath its turf".
The Summer Isles are real enough: a small archipelago near the top of Scotland that Marsden had often gazed at from the shore with a much-loved aunt, and long vowed to visit. En route from the far south of Ireland, though, are places that can't be seen on satellite imagery because they exist, or existed, only in the imagination: islands that appeared once every seven years; islands that "drifted about like giant plankton"; islands that, when the crews of St Brendan and Máel Dúin lit fires on them, turned out to be giant sea creatures. There, ships crossed the sky, fairies lived below ground and a rabbit was seen playing the flute.
The story about the rabbit was relayed by an islander not so long ago, in the 1890s, to the Dublin playwright JM Synge. He was on Inis Meáin, middle of the three Aran Islands, which lie like a school of whales across the mouth of Galway Bay. Fields there are bounded by drystone walls, but fancy can run free.
I once spent a few days wandering all over Inis Meáin. By the end, I found it easy to understand why belief in the fairies had persisted there until well into the 20th century. Surely that fish-shaped indentation in the limestone couldn't have been made by natural forces? And that table-flat, cliff-edge projection... wasn't that the work of a giant mason? As the sun sank one evening, I paused with my camera at a deserted, overgrown house to try to capture the light raking its front door. The door swung in the breeze, and I jumped a foot in the air.
Reading of Marsden's time on Inis Meáin, I was carried back to that evening. I felt what he calls "the piercing of the present to reach a season long gone". His book, like one of those doorways so popular in Irish myth, is a portal not just to other places but to other times. It's a reminder, too, that "the imagination is the oddest of human faculties, and also perhaps the greatest". Don't get the idea that Marsden, in a phrase I heard often as a child, is "away with the fairies". He has a degree in anthropology himself, and has written acclaimed works of non-fiction.
His book is as sound and well balanced as his old wooden sloop, and its author has his head screwed on - unlike an American he met on one of his evenings in the pub, who was planning to head for Greenland with no instruments and no radio. None of the locals, well able to imagine the worst, would sail with him.
A couple of them did briefly join Marsden, rightly sensing he could be trusted. He has been sailing since childhood, and bought his first dinghy with the advance for his first book (about Ethiopia, published in 1990), though he admits that until this trip he had "never skippered a boat to anywhere I couldn't reach by lunchtime". He conveys powerfully the fear and the joy of his new challenge; "the fickle extremes of single-handed sailing".
He does so without concessions to landlubbers, without laborious explanations of what exactly he's up to. I don't know what it means to hank on the jib or sweat the halyards, but I know what it is to be borne along by prose as fresh as an Atlantic breeze.
"Watching water move," Jonathan Raban wrote in his modern classic Coasting (1986), "is a much sweeter and less unpredictable way of altering the mind than inhaling the smoke of marijuana". Reading Marsden on watching water can be similarly effective in opening the doors of perception: he tells how "a low surf folded its queries on to the sand"; he reckons that "white horses" must be a description of wave crests first coined from the land - "at sea, they look vulpine, a pack of pale predators cantering across the open plain".
"Stepping ashore on these islands," he writes of one place, "always brought its own thrill of anticipation, like meeting someone new, or reading the first pages of a book. What would they be like? Would you grow to love them?"
I loved The Summer Isles from page one.