Calls for assisted dying, euthanasia, to be legalised are on the rise. While many do not think it is morally wrong for a dying person to voluntarily end their life, concerns about the knock-on consequences of legalisation often stand in the way of changing the law. The slippery slope argument stands in the way of assisted dying. Such arguments are often a rhetorical device, that use suffering patients as a means to an end and not as ends in themselves, writes Emily Jackson.

Slippery slope arguments are generally employed in order to argue against doing something, on the grounds that even if doing the thing itself might be unproblematic, doing it is likely to have unintended and undesirable consequences. A slippery slope claim is not concerned with whether a particular activity is right or wrong, but with whether it is in practice impossible to confine ourselves to that activity only.

There are two different reasons why a slope might be slippery. In a logical slippery slope argument, the claim is that that once we allow activity A, there is no non-arbitrary reason to stop there, and so we are logically committed to also allow activity B. An empirical slippery slope argument suggests that once activity A becomes familiar and routine, taking further steps towards activity B will begin to seem less problematic, and we will eventually find ourselves accepting activities B, C and D.