Darwin understood the need for animal tests

Charles Darwin had a thing about worms. His final book was about their impact on soil, and their contribution to the evolution of other species. Despite its title, Vegetable Mould sold even more briskly than On the Origin of Species - an indication of the extent to which Victorian society lionised the great man of Nature.

In his autobiography, Darwin records his earliest encounter with animal suffering, and his instinctive abhorrence of it. The victim was an earthworm, the evil done, impalement on a hook for fishing. He describes his satisfaction at discovering that he could kill worms in advance by immersing them in salty water. He never again “spitted a living worm, though at the expense, probably, of some loss of success”. He does not record similar concerns for the fish.

“I was as a boy humane,” he wrote, although he enjoyed shooting as well as fishing. He admits one particular act of cruelty - beating a puppy, “simply for enjoying the sense of power”, when he was a schoolboy. “This act lay heavily on my conscience” he wrote, “as is shown by my remembering the exact spot where the crime was committed.”

On the 200th anniversary of the birth of the most famous naturalist in history everyone wants to claim a piece of Darwin. Not just scientists, but humanists, atheists, philosophers, sociologists and economists vie for a pound of the great man's flesh. Above all he is embraced by those who argue for the kinship of humans and other animals, and who demand a revolution in the approach to animal welfare.

True to his theory of the continuity and relatedness of all living things, Darwin was moved by the suffering of animals. Indeed, in what was his most remarkable book, The Expression of the Emotions in Man and Animals, he argued that facial and bodily expressions reveal inner feelings - with the implication that animals have fears, pains and pleasures much like our own.

In The Descent of Man, he wrote: “The difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind. We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attractions, curiosity, intuitions, reason etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition in the lower animals.”

So how could Darwin, who championed the living world, who recognised humans as animals, descended from other species, defend the use of animals in research? Should we not be shocked by Darwin's letter to The Times of 1881 defending animal experimentation? Could it have been the confused confabulation of an elderly man, only a year from death?

Absolutely not. Darwin was at the height of his intellectual power and social influence. He was well aware of the reputation that he might lose if he were to alienate his audience of admirers - the middle-class intelligentsia who bought his books in astounding numbers.

Darwin was not muddled, senile or seeking favours. He was pursuing the honesty and integrity that were hallmarks of his work. “I have all my life been a strong advocate for humanity to animals and have done what I could in my writings to enforce this duty,” he states at the start of the letter.

Darwin had been involved in the intense debate that followed the introduction of experimental physiology (the study of bodily function) in Britain in the 1870s, with the establishment of professorships of physiology at Cambridge, University College London and Oxford. The publication of a laboratory handbook in 1873 led Queen Victoria to express concern about “encouraging students to experiment on dumb creatures”.

It was true that earlier experiments in France and Germany had been shocking in their apparent disregard for animal suffering. Indeed, the introduction of anaesthetics in the middle of the 19th century influenced the decision to establish experimental physiology in Britain. It was against this background that Darwin wrote his letter, defending the most-difficult-to-defend. And he did it in remarkably unequivocal terms: “I know that physiology cannot possibly progress except by means of experiments on living animals, and I feel the deepest conviction that he who retards the progress of physiology commits a crime against mankind.”

Today we are all familiar with the arguments of those who oppose animal research. And the tactics of some of them. The rise of extremism in the past few years leaves us principally with memories of arson, intimidation, letter bombs and even grave-robbing. Unfortunately, the criminal stupidity of a tiny minority has cast a shadow over the efforts of the majority of welfare groups, such as the RSPCA and the Fund for the Replacement of Animals in Experiments (Frame), which yearn for a time when research on animals might be unnecessary, but work with and within the scientific community to improve the welfare of laboratory animals and the design and conduct of experiments.

Darwin's own work could be held up as an example of how much can be achieved without resorting to experiments that might cause pain. But he saw that science, just like the complex ecosystems he studied, is a communal process, fuelled by symbiosis, collaboration and interdependence, as much as by competition and predation. Many scientists are fortunate enough not to have to use living animals to advance their area of knowledge, but their work on isolated cells, or computer models, or human patients and volunteers is closely linked to, and dependent on, studies of organ and body systems that are possible only on living animals.

Joseph Lister, whose discovery of antisepsis has undoubtedly saved the lives of millions of people and animals, said it all: “There are people who have nothing against eating a lamb cutlet, people who do not even stop at shooting a pheasant despite the great risk of its... having to die in severe pain - people who still insist that is monstrous to inject a few microbes under the skin of a guinea pig in order to study their effects. These seem to me singularly inconsistent points of view.”

For me, the correspondence in The Times between Darwin, the anti-vivisection campaigner Frances Power Cobbe and others has a special poignancy.

In 1987, without a hint of warning, I found myself the singular focus of criticism from the animal rights movement and then intense harassment for 15 years. It is striking but disheartening to see how similar the arguments are: Darwin's hyperbolic praise for the contribution of animal experimentation to the advance of medical treatment, on the one hand, Cobbe's denial of any benefit and her condemnation of, as she saw it, the inevitable cruelty on the other. Such arguments that are still the stock-in-trade of the two powerful animal rights organisations that Cobbe founded, the National Anti-Vivisectionist Society and the British Union for the Abolition of Vivisection.

I hope that this correspondence might have some influence in the present phase of this debate - the discussion in the European Parliament of a draft directive that would, in the opinion of not only the scientific community but even leading welfare organisations, severely impede the progress of medical research, without obvious improvements in animal welfare.

With the possibility that real extremism is being constrained, we have another opportunity in this country to take the lead in the debate to which Darwin contributed. We must move away from the entrenched positions into which passionate commitment has driven all parties. We need a more nuanced debate that goes beyond the total trust of Charles Darwin and the total opposition of Frances Power Cobbe.

Colin Blakemore, professor of Neuroscience at the universities of Oxford and Warwick and a former chief executive of the Medical Research Council.