Last week British scientists announced a revolutionary screening process for inherited diseases in embryos. It will be quicker and more accurate than the existing method and it will detect thousands more genetic defects than previously possible.

About 200 heritable conditions can be detected by pre-implantation diagnosis in IVF treatment so that only healthy embryos are implanted in the mother or frozen; the new technique — pre-implantation genetic haplotyping — will be able to detect nearly 6,000 diseases and conditions. As one of the British pioneers said, this changes everything. One could almost call it godlike.

What it means is that thousands of parents who are at known risk of passing on terrible disabilities and diseases will now be able to have only healthy babies. This is the best news I have heard for years.

Those who don’t know about it can perhaps hardly imagine the drawn out suffering of Huntington’s disease or Duchenne muscular dystrophy or Prader-Willi syndrome or Fragile X, both for the people affected and for their families, until death puts an end to it.

Nature is astonishingly cruel. Science, by contrast, has the power of mercy. One can only be dazzled by the inventiveness and compassion of the scientists involved in this screening breakthrough — “in action”, as Hamlet said, “how like an angel!” Admittedly genetic screening means that embryos carrying disabilities and diseases will be discarded. It is a stretch, however, to use the word destroyed, or even killed, as the test is done on embryos that are only three days old. And what is appealing about this early screening is that it offers the hope that, in the foreseeable future, abortion and late abortion will be less frequently used in dealing with serious defects and disabilities.

It will be easier and better in every way to get rid of a tiny collection of cells. This is indeed playing God, as all the usual campaigners were quick to point out last week. But what on earth is wrong with humans playing God? I am all for it, especially as God doesn’t seem to be doing it. Besides, whatever we may think about playing God and defying nature, we are doing it already and even though we don’t necessarily recognise it, we approve of it.

For instance, there are many people who in the course of nature would die before they were old enough to have children. They might suffer from inherited heart defects or blood disorders that would kill them if they did not get transplants or dialysis. They might have disabilities that would kill them as newborn babies, without intervention. If properly treated these people may well live to be able to have children and some of those children will be at risk of inheriting the same problems and, in their turn, may pass them down the generations.

Eugenicists might think, and used to say publicly, that this is bad for the gene pool. Yet hardly anybody, I imagine, believes that such people should be denied treatment. It now seems absurd and cruel to suggest that people with heritable problems should not risk having children. It’s hard to imagine the intellectual climate in which Marie Stopes could oppose her son marrying a girl with the heritable defect of short sight.

It is surely the point of modern medicine to relieve suffering and restore people to as full a life as possible. If one wanted to risk sounding unfeeling and darkly Darwinist (and I don’t), one could argue that rescuing such people from extinction is also rescuing their disability from extinction — a godlike activity, surely.

Such is the miraculous power of human invention that even this problem is on the way to being solved — by the screening tests announced last week. One way of playing God has now been balanced by another, even more ingenious, human invention. That is the way of science. It mystifies me that so many people oppose it.

There will always be absolutists, who claim the right to life for even the most infinitesimal scrap of tissue. But there are others who oppose screening on what seem to me to be even more irrational grounds.

Simone Aspis of the British Council of Disabled People said last week that she was opposed in principle to such screening on the grounds that it sent the signal that being born disabled was a bad thing. The mind reels. Over the years I have got used to the disability lobby talking in this spirit, so it no longer seems as absurd as once it did, but surely it must be obvious that it would be far better for a person not to have a disability than to have one.

It would be far better to be able to walk, or hear or see than not to. It would be far better not to have a miserable fate like Huntington’s or Fragile X. In a culture where many normal girls are obsessed to the point of illness with their minor imperfections, it is surely better not to have major impairments. In that sense, being born with a disability is obviously a bad thing.

For some reason the disability lobby seems to be in denial about this, perhaps because it’s in the grip of a logical muddle. Apsis made a typical expression of it when she wondered whether the intention of the screening was to remove disabled people. It sent a message, she said, particularly to young people with disabilities, that their lives were worth less than everyone else’s. This seems to me to confuse a disability with a person with a disability. (This is a confusion that people with disabilities normally resent, understandably.)

To say that a disability is undesirable in itself is not to say that a person with that disability is undesirable in herself, or her life worth less than someone else’s. The disability is not the person. It is to say that her life would be better without that disability. And saying it assumes that a person with a life and a history here in the world, with family and friends, is not the same as a minuscule collection of defective cells on a petri dish. One is dispensable, the other most certainly is not.

What a piece of work is a man and partly, now, it is the work of godlike humankind.