Caution: Slippery Slope Ahead! Extreme Arguments are not Persuasive

WHAT IS A SLIPPERY SLOPE ARGUMENT?

Arguments that involve warnings of a “slippery slope” are very common. A slippery slope is a logical fallacy that may appeal to someone’s intuition. A slippery slope is particularly effective when a person wants something to be true but cannot provide a logical basis for that conclusion. It is important to identify when someone is attempting to persuade you with a warning of a slippery slope argument, and it is even more important to make sure that you do not use them yourself. Once a person recognizes that an argument is a caution of a slippery slope it can significantly reduce the trust that the argument is thoughtful.

Simply stated, an argument that is a caution of a slippery slope begins with a statement of something that every person agrees must be avoided. The argument then traces a single series of events that could potentially result in that situation and then argues that every step in that series must be avoided.

Here is an example, that is exaggerated for effect:

No one wants to be exposed to toxic mould in their homes. Toxic mould is caused by moisture in attic spaces and moisture in attic spaces is the result of leaks in the roof. Leaks in the roof are caused when there are breaks in the roof that are not properly sealed. It is more difficult to seal a shingle roof than it is to seal a metal roof with overlapping metal panels. It is most difficult to seal around penetrations in a that are required for skylights. Therefore, if we don’t want toxic mould we need to remove all the skylights and replace the roof.

When considering an argument that involves a series of intervening events, it is important to consider whether the connections are inevitable or whether they are only one possible series of events. Similarly, it is important to examine what options are available to intervene in the series rather than simply accept that if the first step will lead to the proposed conclusion.

A common variation on the slippery slope argument is an argument involving "precedent". We discuss that in another article.

SLIPPERY SLOPE ARGUMENTS REDUCE TRUST AND ARE NOT PERSUASIVE

It is important to identify when someone is attempting to persuade you with a warning of a slippery slope argument, and it is even more important to make sure that you do not use them yourself. Once a person recognizes that an argument is a caution of a slippery slope it can significantly reduce the trust that the argument is thoughtful.