'PERHAPS because I have ended up searching simultaneously for a better understanding of my own life and of what can be done to rescue the global environment, I have come to believe in the value of a kind of inner ecology that relies on the same principles of balance and holism that characterise a healthy environment. For example, too much of a focus within seems to lead to a certain isolation from the world that deprives us of the spiritual nourishment that can be found in relating to others; at the same time, too much attention to others - to the exclusion of what is best understood quietly within one's own heart - seems to make people strangers to themselves.'

Who wrote that interesting paragraph on the balance between the contemplative and the active life? The phrase, 'the global environment', shows this is a modern writer, and the word 'holism' is also a 20th- century usage. The same author wrote, in another characteristic passage: 'Francis Bacon is a case in point. His moral confusion - the confusion at the heart of much of modern science - came from the assumption, echoing Plato, that human intellect could safely analyse and understand the natural world without reference to any moral principles defining our relationship and duties to both God and God's creation . . . since the onset of the scientific and technological revolution, it has seemingly become all too easy for ultra-rational minds to create an elaborate edifice of clockwork efficiency capable of nightmarish cruelty on an industrial scale. The atrocities of Hitler and Stalin, and the mechanical sins of all who helped them, might have been inconceivable except for the separation of facts from values and knowledge from morality.'

Perhaps those who find any discussion of spiritual and moral issues embarrassing will be embarrassed by these paragraphs. Certainly those scientists who find it difficult to cope with the moral responsibilities of science will find them offensive. Yet to many of us they would seem a thoughtful attempt to discuss some of the central issues of the modern world. No one can hope to reform the world who has not first tried to reform his own spirit.

Who is it that wrote these passages? Not, as one might suppose, a bishop or a theologian. Not a Buddhist student of the Dalai Lama. Not even a professional ecologist from one of the environmental pressure groups. These are quotations from Senator Al Gore, the Democratic candidate for Vice- President of the United States.

They come from his new book, Earth in the Balance (Earthscan, pounds 14.95). As I understand it, the book was not favourably reviewed when it was published this year in the US. The Republicans have tried to use it against Al Gore on the grounds that he talks to the trees. I did not expect much when I opened it. Politicians' books, except when written in retirement, are usually bad. A politician cannot afford to be frank; he may alienate too many potential supporters. Yet Senator Gore's book is the frankest and most important publication by a current politician I have read in a long time.

His cast of mind and spirit do make it attractive. Few politicians pretend to be spiritual or even serious men; Edward Boyle was one among my contemporaries, but most of politics is a moral compromise that spiritually concerned people find repugnant. Like Edward Boyle, Senator Gore is serious and inwardly concerned for the wellbeing of the world. That does not make him a prig but it does make him the most interesting of the four candidates in this presidential election.

His character comes from his Christian faith. He is a Baptist, but the formation of his Christianity is ecumenical. I did not guess his denomination until he mentioned it in passing near the end of the book. He believes that Christians owe a duty both to their neighbours and to what Oliver Goldsmith called 'animated nature'. Human beings are stewards of the earth, and we are neglecting our stewardship. We are mining the earth's resources rather than farming them, and imposing pollution and suffering both on the poor and on future generations. We live in a selfish and reckless generation.

There are parts of Senator Gore's book that overlap with The Great Reckoning, the book James Davidson and I published in the US last year. We were chiefly concerned with social, economic and historic development; he is primarily concerned with the environment. Yet his chapter on 'Dysfunctional Civilisation' deals with ideas that run through both his book and ours; we would wholly agree with his view that 'our dysfunctional civilisation has developed a numbness that prevents us from feeling the pain of our alienation from our world'.

We would also share his concern with those social developments that are reflected in explosive changes. He refers to the increase of carbon dioxide in the atmosphere; to the growth in human population; to the spreading damage to the ozone layer. He gives a thorough account of the expert evidence, but as a politician and journalist who does not pretend to be a scientist or an expert.

We reported similar explosive changes: the trend of debt in the world economy, the rise of crime and drugs in society, the spread of disease and particularly of Aids. Each of these explosions is, by its nature, unsustainable. For instance, we forecast that the world economy could not sustain the debt expansion of the Eighties. Plainly we proved correct. Senator Gore is forecasting that the environment cannot sustain the increasing abuse and exploitation of an exploding human population, combined with the equally explosive development of technology.

Is he right or are the Republican spin-doctors, who snigger at his concern for the environment, justified in their sarcasm? For the past five years California has been experiencing ever-worsening drought. Some climatologists have predicted the loss of 75 per cent of its annual moisture as a result of global warming. Thousands of Californians lost their homes in the fires of 1991. Last week's news reported even worse fires that made thousands homeless near San Francisco. The small pieces of evidence are slotting into place.

Herbert Lamb, another expert on climate, writing about the Sahara region, has warned that: 'Some complete national territories may, in the long run, become more or less uninhabitable if the development continues and goes further.'

That is the terrible tragedy now being reported from Somalia. We are still at an early stage of the explosive increase of carbon dioxide and global warming, as we are of the Aids epidemic. But all the newest evidence is what one would expect if the forecasts were broadly correct.

Al Gore's 'Global Marshall Plan' to save the environment is at least better than global cynicism, but it is the educational effort that is the most valuable part of his message. Education is our most effective weapon against global warming, as it is against Aids - perhaps it will prove to be so against drugs and debt as well.

No one can yet tell whether the Democrats will win and Al Gore will become Vice-President. In my view, there are unsustainable commitments in the Democrats' policies on public expenditure. Yet it is good that American politics can produce a potential leader of this quality. Senator Gore's book is at the other end of the scale from the manipulation of the 20-second sound-bite. He is a man of thoughtful and questioning Christian faith, who has tried to explain to his fellow Americans great issues in a context that is both spiritual and realistic.