How many thoughts do we have each day? Some conscientious wag has counted and come up with a figure of 60,000. Of these, 58,000 are apparently the same thoughts we had yesterday. No wonder we are bored with our own company. However, clever people - and in particular creative people - have gaps between thoughts, which is why they come up with new ideas. Simply put, this seems to me what transcendental meditation does: it transcends - or goes beyond - thought, providing these gaps and allowing the mind to programme itself afresh. You do it for 20 minutes, morning and evening.

I learnt about it 15 years ago. A friend I met on a train had just taken it up and I was curious. I don't know what I was expecting but certainly not what happened, which was that after two months I could climb the stairs without taking a puff of my inhaler. I had suffered from asthma since the age of six. They said six puffs of the inhaler a day would fix it, but I was having about 20. After coping with the stairs, I left the inhaler behind when I went out. Then I went away for the weekend without it. Then I forgot about it altogether and haven't used it for years. I learnt that during meditation our oxygen intake drops by 16 per cent.

Transcendental meditation, or TM, is a technique you learn, like driving a car. You don't have to believe in it; indeed you can think it's a load of old rope but if you do it, it will work. You don't have to sit in the full lotus position with a soppy smile on your face. You can meditate in an armchair, on trains and in aircraft.

You must have a qualified TM teacher. First there's an introductory talk, which is free. It's a good idea to take along the person you live with, so he or she doesn't think you're up to anything creepy. After the talk, you need never return. All six of us did: my daughter and I, a schoolboy, a middle-aged woman from South America, a deep-sea diver and a student. Our teacher was using the ocean as a simile for the mind: the ocean was rough and choppy on the surface, she said, but silent and still at its vast depths. The deep-sea diver was happy to confirm this.

If you decide to learn, you pay £1,280, which is expensive, but you've got it for life. In a little private ceremony, usually in your teacher's house, you are given a mantra, a meaningless Sanskrit word suited to your physiology, and taught how to meditate. It's a grave mistake to pass the mantra on to anyone else whose physiology it might not suit. Its purpose is to charm the mind away from thought. After all, thinking "I must rid my mind of this thought," is just another thought. The hardest thing is learning not to try.

Then you all meditate together, after which the teacher asks you what it was like. The diver had experienced exciting fizzing sensations in his forehead, the student seemed euphoric, and the woman from Latin America couldn't remember much about it, though she said the 20 minutes had gone in a flash. The schoolboy pronounced it "good fun", my daughter thought she might have dozed off, and my hands had become pleasantly warm. All these reactions were fine, our teacher said; stress was being released. Over the next three months we returned four times for group sessions and to have our meditating practice checked.

The teaching of TM has been handed down over thousands of years by word of mouth. The practice was brought to the West in the late Fifties by Maharishi Mahesh Yogi, a man with a degree in physics from the University of Allahabad. He lived in an ashram in the high Himalayas with his teacher Brahmananda Saraswati, to whom he always refers as Guru Dev. (In the Sixties the Beatles, with attendant publicity, all went to India to learn TM from the Maharishi). There are about five million people practising TM in the world, 300,000 of them in Britain.

The concept of "stress" - commonplace today - was first put forward in the Thirties by Hans Seyle, a Canadian doctor. In the Seventies he turned his attention to TM and discovered that meditators recovered from stress and shock much more quickly than others, since when there have been hundreds of scientific studies that indicate its efficacy in treating high blood pressure, heart disease and addiction of all kinds, even heroin. Several studies have been done on ageing: the hormone DHEA that runs down with age remains at a higher level in meditators, as does sharpness of hearing and vision. In 1982 the International Journal of Neuroscience published a study of older people which showed that those who had been meditating for over three years were 11 years "younger" than their real age.

I am sometimes asked about the practicalities of meditation. People listen and then say comfortably, "Oh, I couldn't sit still and concentrate for 20 minutes," or
" I have too many thoughts." Sometimes they say, "Oh, I learnt but it didn't do anything for me" - and you find they tried it for just a fortnight.

The Born Agains will say, "You're emptying the mind, the Devil will rush in." You could ask them what the Devil gets up to when they're asleep. Indeed, the mind is curiously alert during meditation: you are far more likely to hear the first cuckoo or the death watch beetle in the attic. The Born Agains will tell you there's no meditation in the Bible, but the Bible is full of it: "Be still then and know that I am God," says the psalmist. It is the peace of God that passes all understanding. As my friend on the train said, "Now I know what the Holy Ghost has been up to all these years."

The Maharishi talks less about what happens during meditation than its effects on everyday life. He illustrates this by the simile of the bow and arrow: the further back the bow is stretched, the further and faster the arrow carries. I like to think that after 15 years and having done my "A-levels" - the yogic flying course - my work has improved and that I am indeed the sunshine of our home. Little knots of worry loosen: a fear of sleeping in the house alone, a fear of death, grudges borne over years, stabs of guilt about the past. You think of these things and come to realise that they've gone. One is surprised by new insights.

I now realise not only what the Holy Ghost has been up to but what poets are writing about. Then there is bliss. This is an irrational happiness that floods the system - my system all too rarely, but enough to know what it's like. And when you feel it, you realise you had it as a child. When you have this feeling on the London Underground in the middle of the rush-hour, you know you're really getting somewhere.

To learn TM, get in touch with the Transcendental Meditation enquiry office on 08705 143 733 which will send a free information pack and details of your nearest teacher.