Slippery slope arguments, often one of the greatest ways to strike a blow against an opposing view, stand near the top of worst logical fallacies. These arguments, in a formal sense, say that a will necessarily lead to b, and then to c and so on. The end is usually an undesirable state the those making the argument claim is an inevitable outcome from adopting the first premise.
For example: If we allow children to have breath mints in class then we will also have to allow them to chew gum in class. If we permit them to chew gum, we will also have to let them have other candy in class. If we allow candy, then we will have to allow popcorn. If we allow popcorn, then we will have to allow drinks. If we allow drinks then we will have to allow food, etc., etc. ad infinitum.
The problem with such an argument lies in the fact that a may not necessarily lead to b. B may be strongly implied by a, but it may not necessarily do so. Therefore, slippery slope arguments are often dismissed by the side being caricatured because they are often made in overly simplistic terms, ignoring the nuance of an issue.
This does not mean that the underlying concern being raised is not valid. Rather, it means that the way that they are presenting their concern is not formally valid because one thing may not necessarily lead to another.
It’s not uncommon to hear slippery slope arguments dismissed as a scare tactic. However, we should ask whether a way might exist to show the slippery slope. That is to say, if we look around and see others taking similar steps and all ending up in relatively the same place, then it seems probable that something is setting them all on a similar trajectory.
In other words, if we see numerous people following the same path we have to ask ourselves the simple question, “is there a slope?” If group after group keeps following the same and ending up at the same place, it seems likely that there is something that keeps pulling them down.
Refusing to ask whether there is a hill down which others are sliding would be like a boy sitting atop a slide and believing that when he pushed himself forward, he would not follow the slope of the other kids before him but would rather continue forward through the air. Without the presence of a significantly different factor, like a jetpack strapped to his back, the boy will slide down just like every single child before him.
The importance of this argument comes into sharp relief when we consider the trajectory set by those who advocate “options” for care at the end of life. By options, they mean physician-assisted suicide. They often begin by saying that it would only apply to those with terminal diseases and that it won’t be expanded to other cases. They claim that fears are unfounded because we are only talking about a small segment, but those numbers always increase.
Yet this is the same argument that we have seen made time and time again in country after country. And time after time we have seen country after country slipping further and further down the slope. Promises were made about limitations are set aside, leading to the recent development of involuntary euthanasia, i.e. murder.
We must be wary of slippery slope arguments, but we must also question those who, in the face of ample evidence, deny that a slope exists.