In the black gloop of down-beat news on global warming and Iraq, we sometimes forget that, in at least one respect, we are living through a shimmering moment of progress that should fill us with awe. The 21st century is - as the science writer Ronald Bailey puts it - an era of Liberation Biology. Every week now, scientists are steadily defusing the diseases that have cut human life short for millennia, and stolen from us the grandparents we never knew or the lovers who died too soon. They are setting us free.
Only yesterday, it was revealed by Yale University scientists that they have been able to make primates with severe Parkinson's disease walk and eat unaided, by injecting them with human neural stem cells. The implications for further research into humans are obvious - and dazzling.
Even those of us who are not privileged to be scientists can get the gist of what is happening. In 1998, researchers were first able to isolate embryonic stem cells - immature cells taken from human embyros.
These cells matter because they have the potential to develop into many different types of tissue. Scientists are now slowly discovering which molecular signals make them develop in different ways. If they can unlock this code - if they can make the cells grow into whatever we need - they will be able to transplant nerve cells into broken spines, making the lame walk. They will be able to inject insulin-producing cells into diabetics. They will be able to generate motor-neurone cells to treat Parkinson's. And on the list goes, each one freeing millions of humans from misery.
But - incredibly- there is a large slice of humanity that stubbornly refuses to see any of this as progress. Instead, they see it as a massacre.
The religious backlash against Liberation Biology has been viciously successful, holding back scientific progress in almost every part of the world. In Nigeria, mullahs have this year successfully prevented the World Health Organisation from finally eradicating polio from the human condition, by claiming the vaccine is part of an "anti-Islamic plot" and ordering their congregations to refuse it.
In the US, President Bush again pledged this week to veto legislation sent to him by Congress that would permit federal funds to be used for stem-cell research. And - lest we Europeans get smug - Britain is about to introduce new laws restricting the development of "hybrid embryos" that will slowly strangle life-saving research.
This is all part of an old story: the conflict between science and religion. For all the prattling by bishops that there is "no incompatibility here", in reality they are based on fundamentally contrasting ways of understanding the world. Science is based on strict empirical observation of the world, and deductions based on reason from it. Faith is based on divine revelation (that is, hallucination), or following the words of men who claim to have experienced it.
This battle has been playing out ever since modern science developed. The religious damned autopsies, organ donation, IVF, and even pasturised milk. Today, they are trying to halt the latest wave of Liberation Biology because they claim that blastocysts - hollow spheres of cells almost invisible to the naked eye - are "human beings," and therefore cannot be harvested for life-saving stem cells.
What fact or reason can they point to, to make this point? There are none. We can see through empirical observation that blastocysts have no brains, no thoughts, no capacity to feel pain. So the religious ignore empirical fact. Instead, they say that an invisible thing called "the soul" magically appears at the moment of conception. How do they know? They just do. Okay?
These beliefs have animated the hardcore evangelical base in the US to fight to retard and suppress research - and they have won. If they can delay research in America - which is the world's laboratory, due to its pro-science Enlightenment constitution - they can do it anywhere.
Scientists have been forced by this backlash into a massive diversion, where they have had to try to use adult stem cells instead. Until recently, it was thought that they are only capable of forming their tissue of origin, making them far more limited. But it seems there has been a breakthrough: researchers at UCLA claimed last month that they have been able to take normal adult tissue cells and reprogramme them to act as embryonic stem cells.
So is there, at last, a chance to dodge this debate with fanatics and make progress? Sadly, it's not that simple. Previous "breakthroughs" in this area have turned out to be dead-ends. And even if this isn't another one, adult stem cells are much harder to harvest at a reasonable cost. It takes human embryonic stem cells 25 days to grow from 10 million cells to 10 trillion cells. It takes adult stem cells two weeks longer, and it takes a hundred times more tissue culture surface to do it. So research based on adult stem cells will be slower, burn up more of the limited research funds - and therefore save fewer lives.
Here in Britain, we have a more subtle problem, with the debate focusing on the plea by scientists to allow them to create "hybrid embryos" - taking an animal egg and injecting it with human DNA. They need to do this because there are so few fully human stem cells to experiment with. At the moment, they are dependent on the cast-offs from IVF. By contrast, acquiring and adapting animal eggs offers an almost unlimited supply.
But a string of tabloid headlines immediately conjured images of "chimpmanzees" and "pig-girls" being made by latter-day Dr Moreaus. One headline shrieked: "Can centaurs and talking pigs be far behind?" This is a pig-ignorant question. At Newcastle University, for example, the team led by Lyle Armstrong wants to use cow eggs to develop treatments for diabetes and paralysis. These are not villains; they are heroes. We should be cheering them on, not throwing obstacles into their paths.
But the Government is doing just that. In December, they announced an outright ban on hybrid embryo research. Last month, they backed off - but only a little. The 1990 Human Fertilisation and Embryology Act - which has covered these issues until now - outlined a few general ethical rules of thumb, but left the science to an independent body of experts to assess. The new legislation junks this approach, instead offering mind-boggling detail outlining very narrow confines within which scientists can operate.
There is none of the openness to new development of the old system; in time, it will choke off innovations in the name of primitive, unfounded fears.
Progress, it seems, never comes without a punch-up. Even the most beautiful advances are fought against, by people speaking in the name of "prophets" who thought demons and witches caused illnesses. Every day they succeed in delaying this research is a day thousands of us die unnecessarily.
© 2007 The Independent