Slippery Slope




Also known as: The Camel’s Nose


The Slippery Slope is a fallacy in which a person argues that one thing must inevitably follow from another without adequate support for this conclusion. It can also occur when there is not a claim of inevitability; if the inference that one thing will follow from another is not adequately supported, then the fallacy occurs.

Most commonly, the fallacy occurs when there are a series of steps or gradations between one thing and the other and no reason is given as to why the intervening steps or gradations will be bypassed. This reasoning has this form:


Premise 1: X has occurred (or will or might occur).

Conclusion: Therefore, Y will occur.


This is fallacious because an argument gives no reason to believe that one thing must/will follow from another when no reason is offered to support that claim. This is especially clear in cases in which there are a significant number of steps or gradations between one thing and another.

A person might commit this fallacy in error, or they might do so intentionally. For example, a politician might claim that regulating social media content would lead to the end of free expression when they are well aware that this is just hyperbole.

This fallacy is often used to argue that X should be prevented to prevent Y. In such cases, Y is something that the target audience is supposed to believe is bad. For example, someone might claim that any censorship would lead to the banning of all books to argue that there should be no censorship. This reasoning can be presented as an extended argument:


Argument 1

Premise 1: X might happen.

Conclusion: If X happens, then Y happens.

Extended Argument

Premise 1: If X happens, then Y happens.

Premise 2: Y is bad

Conclusion: X needs to be prevented.


While it is usually reasonable to prevent bad things, the extended argument rests on the unsupported conclusion that Y must (or will) happen if X does. Since this reasoning lacks logical force, it gets its influence from psychological force. This psychological force is often created by using hyperbole in presenting Y. Other fallacies can also be used in conjunction with the Slippery Slope, such as using a Straw Man for Y or employing Appeal to Fear or Appeal to Spite to make the target audience afraid or angry about Y. Y can also be a complete fabrication. The goal is to use the target audience’s emotional response to Y to convince them both that X will lead to Y and that X must be stopped.

While they are rare, there can be what might be called Positive Slippery Slope fallacies. These would use the Slippery Slope logic, but Y would be presented as good, and the conclusion would be that X should be done to bring about Y. For example, a con artist might claim that if someone invests a little in their scam, then they will inevitably get a huge return. This fallacy could also be committed in good faith, where the person committing it really believes that good will result.

What can create some confusion is that non-fallacious Slippery Slope arguments are also called Slippery Slope arguments. In fact, people sometimes exploit this confusion in bad faith. A non-fallacious Slippery Slope is an argument in which adequate reasons are advanced that support the claim that if X happens, then Y will (or is likely to) happen. This reasoning has this form:


Premises: The steps/connection between X and Y are presented and adequately supported.

Conclusion: If X occurs, then Y will occur.


Provided that the connection between X and Y is adequately established, this can be a strong inductive argument. For example, one could make a good Slipper Slope argument that experimenting with highly addictive drugs could lead to addiction. Good Slippery Slope arguments are often boring, since they tend to involve presenting all the intervening steps and showing how they are connected. A fallacious Slippery Slope will almost always have far more persuasive power, which is one reason why the fallacious versions are more common.


Defense: Since a Slippery Slope fallacy involves asserting that one thing follows from another without adequate evidence being provided, the defense is to see if such evidence is presented. If not, then the fallacy has been committed.

Since those intentionally using this fallacy will usually try to make Y appear especially awful or scary, it is also important to be on guard against the psychological influence of this tactic. One should ask whether they have been given a reason that this will or must occur, or is there merely an attempt to use fear, anger, etc. to cover up a lack of evidence for the alleged connection?


Example #1:

We must stop the tuition increase! The next thing you know, they’ll be charging $100,000 a semester!”


Example #2:

“Europe shouldn’t get involved militarily in other countries. Once they send in a few troops, then they will send in thousands to die.”


Example #3:

“You can never give anyone a break. If you do, they’ll walk all over you.”


Example #4:

“We’ve got to stop them from banning pornographic web sites. Once they start banning that, they will never stop. Next thing you know, they will be burning all the books!”


Example #5

“We can’t allow same-sex marriage; if we allow that, then people will be marrying their cars.”


Example #6

“We can’t allow different-sex marriage; if we allow that, then people will be marrying their cars.”


Example #7

“Media companies need to stand strong against the woke mobs who want more trans characters in shows and movies. The next step is brainwashing our kids to get sex changes!”


Example #8

“Media companies need to stand strong against the mobs who want more straight characters in shows and movies. The next step is making all our kids straight!”


Example #9

“Look, if we do not pass this law that requires people to have state IDs in order to vote, then the next thing that happens will be millions of illegals voting in every election.”


Example #10

“I’m against this tax cut. If I do, the next thing you know there will not be any taxes. That might sound great, but that also means no roads. The entire country would collapse!”


Example #11

“We cannot allow any restrictions on abortion. If we allow even one, then it will be the Handmaiden’s Tale! Only for real!”

Originally appeared on A Philosopher’s Blog Read More



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