There is no cherished assumption that now goes unchallenged. The latest one is that country air is good for you. Ronald Reagan was much mocked when he said in 1981 that ‘trees cause more pollution than automobiles do’, but scientists later surprised everyone by saying that he was at least partially right. And now it is claimed that if you live near to a pig, cow or chicken farm, you might as well be living in Oxford Street. A study conducted by Utrecht University in Holland has found that more Europeans die from air pollution in the countryside than in cities, mainly from the fumes of manure storage and slurry spreading.

Of course, this may not be true; for no such findings ever get unanimous acceptance. China and the United States, the world’s two biggest emitters of greenhouse gases, may even agree between themselves that they are to blame for global warming; but there are also plenty of people who declare them innocent and insist that climate change is a natural phenomenon in which humans play no part. The frustrating thing is that people are never allowed certainty. There was, for example, much complaining after the June referendum that nobody in the campaign explained what the consequences of Brexit would be; but nobody did, because nobody knew.

But back to the countryside, where I have been hoping to spend my final years. At my house in Northamptonshire I have six chickens of my own, which probably aren’t enough to do me much harm, but I also live near to a large commercial chicken farm that may well be poisoning the air. I can, of course, refuse to believe this, but there is one incontrovertible fact about the countryside that I cannot ignore; and this is that it’s not a good place to live if you can’t drive a car.

I was just reading an article in the New York Times by an elderly American who has moved after 45 years in Texas to live in New York City so as to escape the motor-car. ‘Driving closes the mind to everything except driving,’ wrote Willard Spiegelman. ‘Walking opens it.’ But that’s all very well for him, who has other reasons for wanting to spend his old age in New York, such as the ‘comforting’ way in which ‘the anonymity of metropolitan life gets you ready for the anonymity of the grave’. It’s different, however, for someone who finds that aspect of city life less ‘comforting’ than Mr Spiegelman and prefers green fields, wildlife and birdsong. For him the car is essential.

The carless country dweller can’t go anywhere or do anything without somebody’s help. He can’t go shopping or make expeditions without being driven. He has to plan everything in advance. He can’t be spontaneous. He has sacrificed his autonomy. And having had to surrender my driving licence for health reasons, this is the position in which I also find myself. It makes city life suddenly seem much more appealing. And even if I get my licence back in due course, there is likely to come a time when I won’t be competent to drive anyway, and when the city will be the only solution.

But there is hope looming on the horizon, and this is the driverless car. It may take a long time to arrive; but when it does, it will transform the lives of elderly country people. Not only will they become their own masters, with their own obedient robots to take them wherever they want to go; they will even be able to have an enjoyable time on their car journeys. They will be able to drink with impunity, read a book, watch television, or lie down for a sleep. They will never worry about how to park — the car will do it for them — nor fear speeding tickets.

The driverless car does face certain possible risks. Computer hackers may try to take over cars and use them as weapons, crash them, and steer them into other people. But if all goes well, it will dramatically reduce traffic crashes and make fatal car accidents a thing of the past. It looks like heaven ahead, but the question is when. Some experts think it will take 30 years for the driverless car to become commonplace, others much less. Let’s hope the others are right.