"Do animals have rights?", asks Professor Michael Reiss. And if they do, how can we better make decisions about the animals used for scientific research?
Many people have very firm views about whether it is right or wrong to use animals in scientific research.
Just what rights do animals have?
The question about when such use is acceptable can be put at its starkest by asking: "How many animals is the alleviation of one person's suffering worth?"
This is, in essence, the sort of question that Home Office inspectors have to answer each time they receive an application to use animals in research.
But this question makes the fundamental assumption that animals do not have rights.
If you think animals do have rights, then it is surely immoral to start sacrificing them even to help us.
The whole point about rights, such as the right to education, the right to life and the right not to be tortured, is that they cannot be overridden for someone else's benefit.
It might be thought possible to argue that humans have rights but animals do not.
However, although there are plenty of clear-cut differences between humans and animals, when we think of an adult chimpanzee or gorilla and compare such a creature with a new-born human it is difficult to see why one does not have rights and the other does.
Of course, the new-born human will, all being well, grow up to have the intellectual, linguistic and other capacities of its fellow humans.
But unless you believe, perhaps on religious grounds, that humans are in a fundamentally different category from other animals, it is difficult to maintain any dividing lines between us and other animals.
The morally relevant differences between us and animals, are, surely, of degree, not kind.
The question also makes a second assumption, namely that we can make comparisons across species.
Yet it is difficult to compare the suffering caused by an open wound that you or I have with an open wound a rat, dog or baboon has.
The problems are even greater when we move beyond physical suffering.
Can we, for example, compare human blindness with rat blindness, or Alzheimer's in genetically engineered mice with Alzheimer's in our relatives?
So where does all this leave us in regard to animal experimentation and testing?
A House of Lords Select Committee looked into the workings of the 1986 Animals (Scientific Procedures) Act and reported in 2002.
It concluded that while a number of improvements to the present system could be suggested, the broad thrust of the way in which the use of animals for research and testing is regulated in the UK should continue.
In particular, animals should still only be used when there are no alternatives, and then only if the benefits of their use exceed the costs.
This means that the cost-benefit approach currently in place should continue to be at the heart of UK regulation, as it is worldwide.
But at the same time, one particular problem with the present cost-benefit approach is that the calculations are almost never made.
Nobody ends up saying, for example, that 4,000 mice lost their lives in this research and our best estimate is that as a result x women with breast cancer will each live on average y more years.
One way forward may be to try some retrospective calculations along these lines.
Although difficult, I think transparency and, ultimately, public confidence in the regulatory process would be enhanced by attempts to make these calculations.
Rodents do most of the work in laboratories
This would mean applicants seeking Home Office approval to use animals in their scientific work would be required to provide an attempt at a cost-benefit justification.
It is true that these would not be fully quantitative, but such an attempt at least begins to make it more feasible either to refute or corroborate the researcher's claims.
I am well aware that these proposals carry a number of risks, in particular with regard to inflaming the whole debate still further and, in a worst case scenario, increasing illegal threats or attacks by the minority of animal rights extremists who are prepared to go so far.
However, I doubt that either public policy or the actions of scientists should be determined to too great an extent by such extremists.
Indeed, increasing openness is likely eventually to lead to less extremism.
Michael Reiss is professor of science education at the Institute of Education, London, and director of education at the Royal Society. These views are those of the author and should not be taken as being the views of the Royal Society.