One striking thing about modern Western societies is how quickly bioethical practices that would once have been shocking quickly become un-remarkable. It happened with abortion, it happened with embryo selection, and now it is happening with euthanasia. It emerged that during 2016 and 2017 three children in Belgium were given euthanasia, and the media reaction was one giant shrug. As far as I am aware it has barely been reported outside Christian and pro-life circles.

Pro-lifers who warn against weakening the legal protection offered to all human life are often accused of believing in the supposed “slippery slope fallacy.” But the Belgian experience, over the 16 years since euthanasia was introduced, suggests that logical slippery slopes do exist.

Once you have conceded into law a particular ethical principle – say, “intentional killing is a legitimate treatment option for patients who request it, or whose best interests demand it” – it is very difficult to control the further application of that principle, because of the way the law works, with a high value attached to precedent and equal treatment. By the internal logic of the pro-euthanasia position, any law or ruling permitting some form of euthanasia carries within it the seeds of its own extension. If someone with a prognosis of six months is eligible, why not someone with a prognosis of nine months?

If someone who wants to die because of unbearable physical pain, why not someone with unbearable existential pain? And so on.

The direction of travel in Belgium has been clear for a long time. Euthanasia was introduced in 2002 under fairly liberal conditions – for example, the legislation permitted what Belgian law calls “emancipated minors” to have access to it. The numbers taking advantage, steady for a long time at somewhat under 1,500 per year, have recently started to increase. The law allowing children to be killed was introduced in 2013.