The Wild Places, by Robert Macfarlane

Right in the middle of Robert Macfarlane's beautiful and inspiring book about the search for wilderness and its meanings, he quotes something written by Stephen Graham, one of the great English walker-writers of the 20th century. "As you sit on the hillside," Graham wrote 50 years ago, "or lie prone under the trees of the forest, or sprawl wet-legged by a mountain stream, the great door, that does not look like a door, opens."

Macfarlane, a young English don at Cambridge whose first book was a much-heralded history of mountaineering, has here embarked on a wider and more various quest for the forms the great door can take. But as Graham recognised, its very existence is not always as obvious as it might be, and that is where Macfarlane begins. It seems as if the wild places in the denatured archipelago of the British Isles have largely disappeared. What are these islands now but a nest of motorways, a clog of cultivation? He must consult the experts, among them Roger Deakin, the author of Waterlog, a famous account of swimming through Britain, and a man greatly loved by the many who knew him.

Deakin becomes Macfarlane's educator and guide, taking him to his versions of the wild, acting the father figure, being old to Macfarlane's young. The power and poignancy of Deakin's advice is heightened by the fact that he is dying and that too becomes one of the underlying motors of the book. As Deakin's body weakens, even as his mind wanders, as his silences increase, Macfarlane absorbs his deeper and more mature understanding of what wildness means. Although the book is framed as a sequence of travel essays, visiting remote and beautiful corners of the British Isles, it is in fact what used to be called a sentimental education: an account of a sensibility changing, a conscious growing-up in the hands of a dying man.

It starts a little uncertainly off the coast of the Lleyn peninsula. Macfarlane is not at home on boats and gets them wrong. There is only one bow wave to a boat; no one says "eight knots over ground". The cells of the Irish monks on Skellig Michael, whom Macfarlane would like to take as his model, are not carved out of the rock but built on it. The form of the monastery was consciously urban, not submitting to the wild but imposing a Christian civilisation on it.

Skellig Michael wasn't a savage place but a cultivated one, which became the busiest pilgrimage site in early medieval Ireland. Irish nature poetry as a whole was written in mainland monasteries which were among the largest quasi-urban structures of that time. Nor is their art "among the earliest testimonies to a human love of the wild", because Gilgamesh, Homer, Hesiod, Theocritus and Longinus, to name a few, are all full of it.

But when Macfarlane moves into the realities of the landscape, he makes them sing. In part this is a hymn to the bivvy bag, to a man getting to know his country, and submitting himself to its many moods and moments. He looks at a northern river and sees that "The winter sunlight was so bright that it lay in ingots on the riverbed," and that level of engaged immediacy starts to ring through the pages.

It is in part a book about not wasting one's time, about making sure that you don't simply lie in bed at night but see the world when the moonlight and frost are falling on it; that you swim in the phosphorescence that gathers in unseen chains around the coast. The body here doesn't hold itself back at some refined distance but plunges in, gets cold and frightened, is terrified by the "fierce, chaotic, chastening kind of wildness" it thinks it loves.

Under Deakin's example, Macfarlane leaves behind this initial conception of the utter, outer form of wildness. "I thought about how the vision of wildness with which I had begun my journeys – inhuman, northern, remote – was starting to crumble from contact with the ground itself... The human and the wild cannot be partitioned. Everywhere that day I had encountered blendings and mixings."

Moving south, he begins to engage with "the restless changeability of the wild". Deakin and he are in the Burren, in south-west Ireland, looking down into a gryke in the limestone pavement, filled "with a tiny grove of ferns, mosses and flowers. This, Roger suddenly said... is a wild place. It is as beautiful and complex, perhaps more so than any glen or bay or peak."

In this way, the summit-hungry mountaineer moves on to something which Deakin taught him: that the wild is indistinguishable from what it is of its own accord. That is why, in a culture so deeply mired in ironic and borrowed meanings, wilderness has the ability to refresh and renew. Wildness is what it is. And its significance lies beyond what we think it might be. It is a baseline and also a summit

This is not a book of descriptive brilliance, but of controlled eloquence. There is no rage or anger, little that is actually wild, but delicate, conformist, careful. There is a certain disdain for the common man, for the crowds with their chocolate-bar wrappers on the barefoot pilgrimage up Croagh Patrick, for the vulgarity of popular religion. But that, perhaps, is the price to pay for the fineness of a sensibility which suffuses his account of a walk in Cumbria at night in 15 degrees of frost. "You become even more aware of landscape as a medley of effects, a mingling of geology, memory, movement and life. The landforms remain, but they exist as presences: inferred, less substantial, more powerful... Wildness is not only a property of land – it is also a quality which can settle on a place with a snowfall or with close of day."

It is in the end a deeply stirring book, in being able to find the vivid wild in places that are so trammelled with our sterile banks of knowledge about them. In using the body to step beyond the ironic into an immediacy of a tangible, audible, testable world. In reversing what Macfarlane calls "the retreat from the real". Wildness becomes not some fragmentary thing surviving in scraps and fragments which have to be fenced around with a busy protectiveness. It is much much more than that. "I had come to feel wildness as a quality that flared into futurity," Macfarlane writes. "The wild prefaced us, and it will outlive us." It is more than we will ever be. So buy this book and get a bivvy bag. I can recommend the "Jupiter" made by Terra Nova Equipment: expensive, but fabulously weather-proof and life-transforming.

Adam Nicolson's books include 'Sea Room' (HarperCollins)

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