See Animal Research: A matter of life and death for the full list of related content in this week's issue.

Animal research saves lives. That is the mantra often used to counter verbal and physical attacks on animal researchers and their institutions by animal-rights activists. And it is unquestionably true: animal research has made many valuable contributions to medical science.

However, the simplicity of the slogan barely does justice to the complexity of the issue. From a scientific point of view, for example, it is clear that certain animal models are useful: the neural prosthetics that promise to restore some independence to paraplegics, for example, arose from curiosity-driven studies of the primate brain (see Nature 443, 122; 2006). But others are imperfect: certain mouse models of cancer, for example, do not accurately mimic the disease in humans, and may even have hampered the development of some drugs (see Nature 442, 739–741; 2006).

In this week's issue, several articles explore what scientists really think about animal research, and what the future may hold for such work. As part of our investigation, we surveyed many of our readers in the life sciences anonymously, to solicit their views on aspects of the topic. The 1,700 or so readers who responded to our online survey are not necessarily representative of the entire community of biologists, but their responses nonetheless offer some valuable insights into the views of working scientists on questions related to animal research. The complete survey results are published on the web at Given the reluctance of many scientists to speak on-the-record to our reporters on this particular subject (see page 808), the exercise has been helpful in generating an overall picture of how scientists themselves view this highly contentious public issue.

Three-quarters of respondents said that animal research was 'essential' to the progress of biomedical science. However, a minority (fewer than one-fifth) express some misgivings about their work. “As a researcher in the field of HIV vaccine development, I am placed in a very awkward position regarding the use of non-human primates,” said one immunologist. “I personally feel uncomfortable with primate research yet I realize that without primate data, vaccine candidates are rarely forwarded to human trial.”

Fear is clearly a significant factor in excluding the voices of ordinary researchers from public discussion of these issues. No scientist should have to risk life and limb in order to speak about perfectly lawful work. Welcome steps have been taken by governments in both Britain and the United States to pass laws that will protect scientists under the law. And there is some evidence, in both countries, that public support for animal research has actually increased in response to animal-rights extremism.

Our survey also suggests that research agencies, universities and other institutions could do more to ensure that scientists feel free to talk about their work. There are also some indications that peer pressure is not always conducive to open communication with the public about animal research. “I am more concerned that the scientific community, rather than the animal-rights movement, makes it difficult to voice a nuanced opinion on animal research,” said one neuroscientist, whose research involves using imaging to study the brains of human patients.

It is essential that researchers feel free to speak out, both within the community and beyond it, on this issue. If, as seems to be the case, scientists have made some headway in persuading the public of the value of animal research, then this is an opportune moment for them to engage in a full and open debate about the options that lie ahead — including improvements to research practice and the development of alternative approaches.