The contemporary view of scientific research is dominated by suspicion of scientists. Hand in hand with that goes an obsessive protection of research subjects. International agreements and protocols such as the Declaration of Helsinki protect individuals from the dangers of participation in research — but the overwhelming presumption has been, and remains, that taking part in research is an optional and probably a reckless act, not an obligation.It is surely time to recognise that this approach is morally bankrupt and may well be self-defeating. We need to ask whether there is a moral obligation to take part in biomedical research.So far everyone assumes that the answer is "no", and research has almost universally been treated with suspicion and even hostility by the vast majority of those concerned with its ethics and regulation. The result is that much research is becoming impossibly difficult to undertake.The attitude is summed up by the "precautionary approach". This requires dangers to be considered more likely and more serious than benefits. It seems to be accepted that no sane person would or should participate in research unless they have a pressing personal reason for being involved, or are motivated by a totally impersonal and reckless altruism.On the contrary. As citizens, we are obliged to support and even take part in science research. Why? There are two powerful reasons: the first is one of the most overwhelming obligations that we have as citizens, the obligation not to harm others. Where our actions will probably prevent serious harm then, given a reasonable balance of risk and burden to ourselves and benefit to others, we clearly should prevent it. If we see a child drowning in a shallow ornamental pond we should surely pull the child to safety. Another name for this is "the rule of rescue". Biomedical research is a proven rescue service.Participation in research through financial and political support and, if necessary, personal involvement as a research subject is also required by basic fairness. We all benefit from the existence of medical research. Many of us would not be here if infant mortality had not been brought under control, or antibiotics had not been developed. Most of us will continue to benefit from these and other medical advances.Since we accept these benefits, we have an obligation to contribute to the social practice which produces them. Those who reject embryonic stem cell research, including France, Germany and the Bush administration, should obviously agree to forgo any future therapies derived from such cells.We all clearly benefit from living in a society and a world in which serious scientific research is carried out. The knowledge that research is ongoing into diseases or conditions from which we do not currently suffer makes us feel more secure and gives us hope for the future, for ourselves and those we care about.Everyone now living in high-income societies has benefited, for example, either from having been vaccinated against diseases such as polio and smallpox or, from others having been vaccinated. We benefit from so-called "herd" immunity; or we benefit (as in the case of smallpox) from the fact that the disease has been eradicated. We also all benefit from knowledge of connections between diet, exercise and health.It is widely recognised that there is sometimes an obligation to make sacrifices for the community or an entitlement of the community to enforce behaviour in the public interest. This is not, of course, uncontroversial, with the current appeals to necessity in the case of terrorist suspects on many people's minds.We should remember that there are large numbers of cases where we all accept substantial degrees of compulsion or coercion in the public interest. For example in limiting access to dangerous drugs, in doing jury service or in the compulsory wearing of seat belts. Some societies even make voting mandatory. All these involve some denial of autonomy for individuals. Might involvement in medical research be another such case?Mandatory participation in research in the form of the routine availability of our stored biological samples (blood, tissue, organs, etc) or the anonymous use of our medical data would then be justifiable. It is time surely to recognise the overwhelming case for properly supporting research.· John Harris is editor of the Journal of Medical Ethics. A more detailed version of these arguments appears in the April edition of that journal