As the world’s pioneer, the Netherlands has also discovered that although legalising euthanasia might resolve one ethical conundrum, it opens a can of others – most importantly, where the limits of the practice should be drawn. In the past few years a small but influential group of academics and jurists have raised the alarm over what is generally referred to, a little archly, as the “slippery slope” – the idea that a measure introduced to provide relief to late-stage cancer patients has expanded to include people who might otherwise live for many years, from sufferers of muscle-wasting diseases such as multiple sclerosis to sexagenarians with dementia and even mentally ill young people.
Perhaps the most prominent of these sceptics is Theo Boer, who teaches ethics at the Theological University of Kampen. Between 2005 and 2014, Boer was a member of one of the five regional boards that were set up to...