The idea that knowledge is dangerous is deeply embedded in our culture. Adam and Eve were forbidden to eat from the Tree of Knowledge and in Milton's 'Paradise Lost' the serpent addresses the Tree as the 'Mother of Science'. Indeed the whole of Western literature has not been kind to scientists and is filled with images of scientists meddling with nature with disastrous results.

But is science dangerous and what are the special social responsibilities of scientists?

It is essential to recognise that reliable scientific knowledge is value-free and has no moral or ethical value. Science tells us how the world is. That we are not at the centre of the universe is neither good nor bad, nor is the possibility that genes can influence our intelligence or our behaviour. Dangers and ethical issues only arise when science is applied to technology.

But ethical issues can arise in actually doing the scientific research, such as doing experiments on humans or animals, as well as issues related to safety. An important distinction is thus between science and technology, between knowledge and understanding on the one hand, and the application of that knowledge to making something, or using it in some practical way.

Science produces ideas about how the world works, whereas the ideas in technology result in usable objects. Technology is much older than anything one could regard as science and unaided by any science, technology gave rise to the crafts of early humans, like agriculture and metalworking.

Science made virtually no contribution to technology until the 19th century. And even the great triumphs of engineering like the steam engine and Renaissance cathedrals were built without virtually any impact of science. It was imaginative trial and error.

Whatever new technology is introduced, it is not for the scientists to make the moral or ethical decisions. They have neither special rights nor skills in areas involving moral or ethical issues. There is in fact a grave danger in asking scientists to be more socially responsible if that means that they have the right and power to take such decisions on their own.

The social obligations that scientists have as distinct from those responsibilities they share with all citizens, such as supporting a democratic society and taking due care of the rights of others, comes from them having access to specialised knowledge of how the world works not easily accessible to others.

Their obligation is to both make public any social implications of their work and its technological applications and to give some assessment of its reliability. In most areas of science it matters little to the public whether a particular theory is right or wrong but in some areas such as human and plant genetics, it matters a great deal.

The very term 'genetic engineering' conjures up the image of Frankenstein and his monster - Mary Shelley was the unintentional evil fairy godmother of genetics and her creation has been mythologised by Hollywood with Jurassic Park and Godzilla.

The press are all too well aware of this and often publish what I regard as genetic pornography, that is, reports about genetics dressed up to titillate and frighten. For example the widely publicised mouse with a human ear on its back was nothing of the sort but merely a piece of cartilage inserted under the skin. 'Frankenstein foods' provide a depressing further example.

To apply genetic engineering requires considerable scientific and technical knowledge and, even more important, money, which scientists in general do not have. Indeed, for the public sector , the applications of genetics and molecular biology can open up difficult choices because such applications are expensive.

New medical treatments, requiring complex technology, cannot be given to all. There has to be some principle of rationing and this really does pose serious moral and ethical dilemmas much more worthy of consideration than the dangers posed by genetic engineering. So what dangers does genetics pose?

It is hard to find any new ethical issues even in relation to the hysteria over cloning. Some of these common fears are little more than science fiction at present, like cloning enormous numbers of genetically identical individuals. Who would the mothers be, and where would they go to school? In fact it is quite amusing to observe the swing from moralists who deny that genes have an important effect on behaviour to saying that a cloned individual's behaviour will be entirely determined by the individual's genetic make-up. Like identical twins, clones will be similar but not the same because of upbringing and the influence of the environment in the womb.

At present the risk of human cloning leading to abnormalities is high and thus it should not be attempted and I hope no mother would be so unwise to be involved. Gene therapy, introducing genes to cure a genetic disease like cystic fibrosis carries risks as does all new medical treatments.

There may well be problems with insurance and testing but are these any different from those related to someone suspected of having AIDS? Anxieties about designer babies are at present premature as it is far too risky, and we may have, in the first instance, to accept what Ronald Dworkin has called procreative autonomy, a couple's right ' to control their own role in procreation unless the state has a compelling reason for denying them that control'.

Genetically modified foods have raised extensive public concerns and there seems no alternative but to rely on regulatory bodies to assess their safety as they do with other foods. Similar considerations apply to the release of genetically modified organisms. Couples may be faced with difficult choices in relation to prenatal diagnosis of genetic diseases: this can lead to choices not only as to whether or not to terminate a pregnancy but also to inform siblings of a possible genetic risk of which they are not aware.

There are problems, but they, I believe, underestimate people's capacity to deal with difficult choices when they understand what the issues are. Ultimately the choice as to whether or not to seek knowledge rests with the individual.

Most ethical issues in medicine are best resolved by consideration of the rights of the people involved to determine their own future. Scientists cannot easily predict the social and technological implications of their current research.

It was originally argued that radio waves would have no practical applications and Lord Rutherford said that applications of atomic energy were moonshine. There was again, no way that those investigating the ability of certain bacteria to resist infection by viruses would know that this would lead to the discovery of restriction enzymes, an indispensable tool for cutting up DNA, the genetic material, and which is fundamental to genetic engineering.

To those who doubt whether the public are capable of taking the correct decisions in relation to science and its applications I strongly commend the advice of Thomas Jefferson. 'I know no safe depository of the ultimate powers of the society but the people themselves, and if we think them not enlightened enough to exercise that control with a wholesome discretion, the remedy is not to take it from them, but to inform their direction.'