During the past century empires crashed, new states foundered, utopian projects failed and entire civilisations melted down. Revolutionary change was the norm, as it has been throughout modern times. Yet today many of us assume our present way of life will last for ever, and any suggestion that it may be facing intractable difficulties is dismissed as doom-mongering. The result is that the precariousness of modern civilisation is underestimated and the impression that things can go on indefinitely, much as they do now is touted as hard-headed realism.

The Dark Mountain Manifesto begins with the observation that this appearance of stability is delusive. "The pattern of ordinary life, in which so much stays the same from one day to the next," the authors write, "disguises the fragility of its fabric." Written by Paul Kingsnorth and Dougald Hine, this slim pamphlet aims to demolish contemporary beliefs about progress, industrialism and the place of human beings on the planet, and up to a point it succeeds. Much in contemporary thought is made up of myths masquerading as facts, and it is refreshing to see these myths clearly identified as such. The authors are right that none is more powerful than the idea that we are separate from the natural world, and free to use it as we see fit.

But is it true that civilisation is also a myth, as Kingsnorth and Hine claim? Would human beings - or the planet that they are ravaging - be better off if civilisation collapsed? The authors tell us that our present way of life "is built upon the stories we have constructed about our genius, our indestructibility, our manifest destiny as a chosen species".

These legends, they continue, have "led the planet into the age of ecocide". The spread of civilisation and the destruction of the biosphere have gone together. The human future, it seems to the authors, must lie in "uncivilisation".

Kingsnorth and Hine seem to present uncivilisation as chiefly a project for writers and artists. They do not appear to be fixed on tackling environmental crisis with new policies or any kind of political action. A change of sensibility is what they are after, and it is interesting to note the writers they pick out as exemplars of this new view of things.

One is Robinson Jeffers, the once-celebrated and now much-underrated Californian eco-poet from one of whose verses the Dark Mountain project takes its name. Others include Wendell Berry, W S Merwin and Cormac McCarthy. Joseph Conrad is mentioned more than once, and cited approvingly for his view (summarised by his friend Bertrand Russell) that civilised life is "a dangerous walk on a thin crust of barely cooled lava which at any moment might break and let the unwary sink into fiery depths".

It is intriguing to see which writers do and do not make it on to the authors' list. J G Ballard, whose entire work can be seen as an exploration of the flimsiness of civilised existence, is left out, while Conrad's inclusion shows only that the authors have seriously misunderstood him. In a passage quoted in the pamphlet, Conrad writes: "Few men realise that their life, the very essence of their character, their capabilities and audacities, are only the expression of their belief in the safety of their surroundings."

For Conrad, the safety of civilised life was always partly illusory, if only because "civilisation" itself is never more than partial; the heart of darkness was as much in London as in the Congo. But even though civilisation is indelibly flawed, that does not mean it deserves to be destroyed; on the contrary, Conrad was convinced civilisation must be defended with unyielding determination. In reality, the alternative - a raw version of which he witnessed in King Leopold's private fiefdom in the Belgian Congo - is madness and unrestrained violence, a state that can reasonably be described as barbarism.

The authors' misreading of Conrad provides a clue to their reasons for excluding Ballard from their list of kindred spirits. Ballard's early life in a Shanghai internment camp taught him that the disintegration of society does not produce any better version of the human animal. It may lead to a kind of personal liberation - at least if you are an adolescent boy, as Ballard was when he was interned - but overall the result of social collapse is to give free rein to the most psychopathic and predatory among us.

The notion that social breakdown could be the prelude to a better world is a Romantic dream that history has proved wrong time and again. China and Russia have suffered complete social breakdown on several occasions during their history, as did much of Europe in the period between the two world wars. The result has never been the stable anarchy that is sometimes envisioned in the poetry of Jeffers. Instead, it is the thugs and fanatics who promise to restore order that triumph, whether Lenin and Stalin in Russia, Mao in China, or Hitler and assorted petty dictators in Europe. It is the old Hobbesian doctrine - one that has never been successfully superseded.

The authors do not tell us what they expect to happen after civilisation has disappeared, but it may be something like the post-apocalyptic, neo-medieval world imagined by the nature mystic Richard Jefferies in his novel After London, or Wild England (1885). In it, Britain is depopulated after ecological disaster and reverts to barbarism; but it is not long before a new social order springs up, simpler and happier than the one that has passed away. After London is an Arcadian morality tale that even Jefferies probably did not imagine could ever come to pass.

Over a century later, the belief that a global collapse could lead to a better world is ever more far-fetched. Human numbers have multiplied, industrialisation has spread worldwide and the technologies of war are far more highly developed. In these circumstances, ecological catas­trophe will not trigger a return to a more sustainable way of life, but will intensify the existing competition among nation states for the planet's remaining reserves of oil, gas, fresh water and arable land. Waged with hi-tech weapons, the resulting war could destroy not only large numbers of human beings but also much of what is left of the biosphere.

A scenario of this kind is not remotely apocalyptic. It is no more than history as usual, together with new technologies and ongoing climate change. The notion that the conflicts of history have been left behind is truly apocalyptic, and Kingsnorth and Hine are right to target business-as-usual philosophies of progress. When they posit a cleansing catastrophe, however, they, too, succumb to apocalyptic thinking. How can anyone imagine that the dream-driven human animal will suddenly become sane when its environment starts disintegrating? In their own catastrophist fashion, the authors have swallowed the progressive fairy tale that animates the civilisation they reject.

A change of sensibility in the arts would be highly desirable. The new perspective that is needed, however, is the opposite of apocalyptic. Neither Conrad nor Ballard believed that catastrophe could alter the terms on which human beings live in the world. Both writers were unsparing critics of civilisation, but they never imagined there was a superior alternative. Each had witnessed for himself what the alternative means in practice.

Rightly, Kingsnorth and Hine insist that our present environmental difficulties are not solvable problems, but are inseparable from our current way of living. When confronted with problems that are insoluble, however, the most useful response is not to await disaster in the hope that the difficulties will magically disappear. It is to do whatever can be done, knowing that it will not amount to much. Stoical acceptance of this kind is practically unthinkable at present - an age when emotional self-expression is valued more than anything else. Still, stoicism will be needed if civilised life is to survive an environmental crisis that cannot now be avoided. Walking on lava requires a cool head, not one filled with fiery dreams.

John Gray is chief book reviewer of the New Statesman. His most recent book is "Gray's Anatomy: Selected Writings" (Allen Lane, £20)