The achievements of medical science in the past 150 years have transformed our world. It is almost impossible to imagine a time when there were no vaccines against polio and diphtheria, no antibiotics and no anaesthetics, and where open heart surgery, transplants and test-tube babies were the stuff of science fiction.
But which is the greatest medical breakthrough? The British Medical Journal, the house journal for Britain's doctors read by more than 100,000 in the UK and thousands more around the world, is trying to find out, asking its readers to nominate the greatest breakthrough since the journal was launched in 1840.
The BMJ has been inundated with nominations. Announcing the survey in the magazine, Trevor Jackson, a senior editor, wrote: "Trying to answer such questions might seem the stuff of undergraduate essays or medical dinner parties - good fun, but ultimately a trivial pursuit. And yet, in seeking to isolate one breakthrough, we remind ourselves of the interdependence of all these breakthroughs and the importance of all our medical histories. In other words, the process can tell us more than the outcome."
Nominations for the BMJ's survey are now closed, and the 15 most popular breakthroughs are to be featured in the journal over coming months before going to a vote. The results will be published in January.
The Independent has drawn up its own list of the 10 greatest breakthroughs, based on the BMJ nominations. "Breakthrough" is perhaps an overused word in modern parlance but when applied to these discoveries it is, for once, justified.
The contraceptive pill
Inextricably linked with the 1960s, the decade in which it came into widespread use, the Pill revolutionised social and sexual attitudes. It gave women unprecedented control over their fertility; it required no special preparation; and it did not interfere with spontaneity or sensation. For the first time sex became an act of love or of pleasure rather than of procreation, and women could enjoy sex on an equal footing with men.
Today, three million women in the UK use the Pill. But not all societies were equally impressed; in Japan, fears that the Pill would reduce use of the condom and lead to an increase in sexually transmitted diseases prevented it being approved for nearly 40 years. It was finally licensed in Japan in 1999.
Oral rehydration therapy
Which medicine has saved more lives than any other and can be made by anyone in their kitchen, back bedroom, shantytown hut or dwelling built of sticks - as long as they have access to clean water? The answer is: eight teaspoons of sugar, half a teaspoon of salt and one litre of water. Mix. Drink.
The discovery that sodium (salt) increases the absorption of water and glucose from the digestive tract has saved the lives of millions of children suffering from dehydration caused by diarrhoea, the world's biggest killer of children. It requires no specialised equipment; uses ingredients that are ubiquitous and have a long shelf-life; has few side effects; and can be made up in any quantity - the perfect medicine.
It is one of the most effective pain relievers. Hippocrates fed ground willow-bark to women in labour, but it was not until Felix Hoffman, a German chemist, synthesised acetylsalicilic acid in 1897 as a treatment for his father's arthritis that it became the world's best-selling drug, and in 1969 it went to the moon with Neil Armstrong.
In the past 30 years, aspirin has been proved to be effective against heart disease, at least three types of cancer (breast, prostate and bowel), diabetes, Alzheimer's, stroke, infertility and deep vein thrombosis. It is so cheap to make that it cannot yield profits and thousands of research papers each year continue to confirm it as a true wonder drug.
The British gynaecologist Patrick Steptoe and his colleague Robert Edwards were the first to achieve a live birth from an embryo fertilised in the laboratory. Louise Brown was born in Oldham on 25 July 1978 amid controversy over the safety and morality of the procedure. Now 28 and married, she is pregnant with a naturally-conceived child. Today, more than three million babies have been born through in-vitro fertilisation (IVF) worldwide, each bringing joy to infertile couples.
Labour's greatest creation, it has survived almost 60 years and remains envied around the world, especially by finance ministers. Despite current concerns about rising deficits and falling productivity, the NHS delivers more bang for the buck than any health system. Its founding principle of offering universal care on the basis of need, not on the ability to pay, remains as compelling today as it was when the NHS was founded on 5 July 1948. In America, the country with the highest spending on health and the most sophisticated medical technology, at least 44 million people are without medical insurance of any kind.
A mouldy Petri dish standing on a windowsill in Sir Alexander Fleming's laboratory at St Mary's Hospital, west London, led to the discovery of the first effective antibiotic, paving the way for the treatment of infectious disease.
Fleming, with Chain and Florey, shared the 1945 Nobel Prize, and for a few heady years it looked as if infection might be beaten. Instead of patching up the human body, doctors proved themselves able to save lives. But some claim that germ theory - the idea that germs spread disease and that surgeons who failed to wash their hands before operating were transmitting infection - is the more fundamental discovery; it led to the discovery of antisepsis, antibiotics and the transformation of medicine.
William Morton, a Massachusetts, dentist, gave a public demonstration of the use of ether to anaesthetise a patient before removing a tumour from his neck on 16 October 1846. From then on, the development of surgery became possible, the experience of childbirth was transformed and intensive care appeared on the horizon.
In England, ether, which is flammable, was soon replaced with chloroform, which gained royal approval when John Snow gave it to Queen Victoria during the birth of Prince Leopold in 1853. Anaesthesia has made possible "the preservation of human dignity and spirit", said one nomination.
William Röntgen, a German scientist, was working on a cathode ray generator in 1895 when he noticed that it was projecting a faint green light on the wall. Strangely, the light was passing through a pile of materials including paper, wood and books. As he experimented by placing other materials in the way, he noticed that the outline of the bones in his hand was projected on to the wall. Two months later he published his paper, "On a new kind of radiation". Today, radiology is an entire speciality. Medical imaging has advanced to include CT, MRI and ultrasound scanning, used to examine soft tissues for signs of disease.
In 1952 two French psychiatrists, Jean Delay and Pierre Deniker, treated a 57-year-old schizophrenic, Giovanni A, with chlorpromazine, the first antipsychotic drug. Within days he could hold a normal conversation, and within three weeks he was well enough to be discharged.
The discovery heralded a new era in psychiatry. It offered people with unendurable mental illnesses a way out of their misery. And it signalled the end of the asylums and start of community care. Within a decade, the treatment of all mental illnesses had been transformed.
Smoking's link to lung cancer
When Sir Richard Doll published his groundbreaking study in 1950 - the first to link tobacco and lung cancer - the response was sceptical. Smoking was respectable and the tobacco industry was a major contributor to the Treasury. Ian Macleod, the health minister, waited four years before holding a press conference on the findings - and smoked throughout. Today, smokers and the tobacco companies are in retreat. Because of that early warning, published in the British Medical Journal on 30 September 1950, and the campaigns and reports that followed, millions of lives have been saved. Then, 80 per cent of men and 40 per cent of women in Britain smoked; today, one-third of men and women do.