If death and taxes are two of life’s only certainties, then another certainty until recently was that not too many of us wished to discuss the former.

Yet the long-standing taboo in our society has finally been broken, with more people now having frank and open conversations about their hopes not only for a good life but also a good death. Even Margot Robbie’s Barbie recently warmed to the theme, asking during a slumber party with her fellow Dreamhouse dolls: “Do you guys ever think about dying?”

There are many reasons for the shift but in Scotland one factor is Liam McArthur’s Holyrood member’s bill proposing the right for terminally ill people with mental capacity to choose an assisted death, allowing them to die with dignity on their own terms.

Regardless of whether the bill becomes law, it has already notched up a significant victory in generating a debate about one of the few things we humans have in common.

I hope the bill does succeed, giving Scots legal rights already available to hundreds of millions in countries around the world. Nonetheless, arguments against assisted dying persist, including a common claim that people with disabilities unequivocally oppose assisted dying laws - and that those laws harm or disrespect people with disabilities. Without wishing to dismiss people’s concerns, I would respectfully argue that, in fact, the opposite is true.

Some opponents of assisted dying laws persistently suggest there is a consensus among people with disabilities that assisted dying should be prohibited, when this is not borne out by the evidence.

A new YouGov opinion poll published just this week indicated not only that an overwhelming majority of Scotland’s general public (77%) support assisted dying legislation, but that support is higher still (79%) among people with disabilities.

Furthermore, a recent survey of disability rights organisations in the UK indicated varied stances on the matter. Of 140 groups surveyed, a substantial majority either remained silent (84%) or explicitly endorsed neutrality (4%) on assisted dying. Only 4% explicitly opposed it.

At best, assertions to the contrary are emphatic expressions of the convictions only of individual people with disabilities; at worst, they look like morally dubious attempts at misrepresentation. Either way, the overgeneralisation shows disrespect, and does not take seriously the full spectrum of the perspectives of people with disabilities.

So, what of the claim that such laws are especially harmful to people with disabilities, that safeguards inevitably fail, and that there will be a “slippery slope” from rigorous protections to loose and harmful practices? It is interesting, given how often the argument appears, that it tends not to be based on evidence, but made from the philosophical armchair. Maybe that’s because, in fact, it doesn’t stand up to the evidence.

Three systematic reviews published between 2012 and 2016 captured data since legalisation in each jurisdiction on the uptake of assisted dying among vulnerable people, including people with disabilities. Each study found no evidence of assisted dying among people with disabilities at rates any higher than in the general population. Several other studies have reached similar conclusions, including in Oregon where assisted dying has been lawful for more than 25 years.

More research would be useful, in particular to exclude the risk of indirect effects of legalisation for people with disabilities. But the fact that there is no evidence to support claims of disproportionate impact is very revealing, given this point's centrality to many disability-based arguments against assisted dying law. Its absence significantly undermines those claims.

Another claim is that assisted dying laws are disrespectful to people with disabilities, by signalling that disabled lives are somehow not worth living.

That misreports the core of the argument for assisted dying. It is not that some lives are less worth living than others, but rather that each individual must decide what makes their life worth living for themselves — and what to do about it, including seeking an assisted death if that is what they judge to be right. That principle — of equal respect for each individual's autonomy — involves no comparative judgments about how worthwhile different lives are. Indeed, it rules out such judgments.

This line of opponents’ arguments against assisted dying is, in fact, itself guilty of exactly the sin it ascribes to that position, namely of showing disrespect. As the writer Christopher Riddle puts it: “Denying people with disabilities the right to exercise autonomy over their own life and death says powerfully damaging things about the disabled, their abilities, and their need to be protected”.

He argues that we best show respect by legalising assisted dying while also “denying the dominant view that people with disabilities are pitiable individuals, lacking the critical thinking skills required to assess the value of their own lives when weighed against suffering at the end of life”.

It’s important that proponents and opponents of change also show respect for disabled voices by engaging properly with the reasons they articulate for and against assisted dying for terminally ill Scots.

There are undoubtedly challenges, especially in determining whether capacity and consent are present in cases where cognitive functioning or communicative capacity is impeded.

But a blanket prohibition on assisted dying is the wrong way to respond to those challenges. That relies on a pejorative stereotype and ignores how appropriate support can facilitate autonomous decision-making for people with intellectual disabilities.

So, whatever we think of other reasons someone might have for opposing assisted dying laws — religious, moral and political — it is clear that considerations of disability offer no support for that position.

In the face of disagreements, I believe the appropriately neutral stance is to remove the legal prohibition, and let individual citizens decide the difficult ethical questions for themselves. And I believe Liam McArthur’s bill will achieve this, with the benefit of having learned from so much international experience to get the law that best suits Scotland, with rigorous safeguards built in.

But whatever else, let’s at least continue to talk respectfully, and accurately, about life – and death.

Ben Colburn is a professor of political philosophy at the University of Glasgow and a patron of the charity Friends at The End.