What is the Slippery Slope Fallacy, and Has it Gotten into Your Argument?

What is the Slippery Slope Fallacy, and Has it Gotten into Your Argument?

Over at the new FB group for readers of this blog, a couple guys have made tentative stabs at the slippery slope fallacy  discussion question. For those who are scratching heads, here’s a quick rundown of what the fallacy is and what it isn’t, and how to tell whether the slope you’re standing on is real or pretend.  (If you’re in my class on Friday and you’re reading this ahead, thanks, yes, you’ve just seen the lecture notes, I expect good to come of it.)

What’s a Slippery Slope argument?

slippery slope argument claims that some kind of inevitable progression will result from taking a given undesirable first step.  By doing _____, you are stepping off solid ground and are sure to fall into the pit where disaster awaits.  Your cute little snowball is going to be an avalanche before everything is over.  A leads to B which leads to C which leads to D which leads to the unspeakable outcome that is what happens when you make that carefree fatal step of doing A.

Most of us are familiar with slippery slope arguments, and there’s good reason for that, which I’ll explain in a minute.  Meanwhile: When is the slippery slope an error?

What’s a Slippery Slope fallacy?

It is an error to invoke the slippery slope when in fact there is no such inevitable progression to fear.

Let’s take yesterday’s discussion of policies concerning admitting refugees from enemy countries and create a couple fake slippery-slope fallacies.

Fake Argument #1:  “You are proposing to allow some refugees from enemy countries to come to the United States.  If you do that, next thing we’ll be letting in more and more such persons, with fewer and fewer background checks, until finally ISIS can just demand free billboard space on all our interstates.”

This is a fallacy because it claims there exists a progression in which allowing some immigrants necessarily will lead to a loosening of restrictions to the point that all we hold sacred and dear will be destroyed.  If someone were to make such an argument, I maintain it would be a slippery slope fallacy because variations in immigration law don’t, to my knowledge, follow such natural progressions.

Fake Argument Argument #2:  “You are proposing that we place restrictions on who can and cannot enter our country.  Once you start with a few limits and background checks, over time they will just get stricter and stricter, until our borders are completely closed, even to the naive but well-funded foreign tourists who keep alive the billboard industry.”

Again, this is a fallacious argument because it presumes that some restrictions on immigration will cause a series of progressively stricter laws to be enacted.

We can say that the invocation of the slippery slope is a fallacy when it describes something that is not a real slippery slope.  Taking up cigarette smoking doesn’t inevitably lead to over-consumption of diet cola.  Shopping at Dillard’s won’t invariably cause your daughter to join a sorority one day.  One might notice an apparent correlation, but there is not in fact a path of peril leading from point A to point B.

When is the Slippery Slope real?

The slippery slope is an appealing argument because we experience slippery-slope type events in our daily lives.

Some of these are related to individual circumstances.  There do exist people who find that once they have the first drink, they will end up getting drunk.  It would be a fallacy to create a universal generalization (not everyone who drinks does so immoderately), but it would accurate to apply the slippery-slope warning to the individuals for whom this is a real hazard.

Some slippery-slopes are more related to general human weakness.  Once you let someone drop their mail on the kitchen counter, then follows the keys and the bookbag and the science project and the baby’s pyjamas.  You let the kids stay up late this one time and you’ll never get them to bed without a fight again.  Break the diet once, and next thing you know you’ll be back to living off Cheetos and Ovaltine.

These latter situations aren’t hard and fast laws, but they resonate because we’re aware of the way we tend to get sucked into this or that vortex of irresponsibility.

Slippery Slopes with Serious Consequences

There are some well-known cases of slippery-slope arguments that proved true in ways that give pause.  We can read Humanae Vitae and see that what the encyclical predicted did in fact come true.  I would be curious to know if anyone can identify a counter-example; I’m not aware of any.

There are other topics where the slippery-slope argument can be offered in a moderated way.  Arguments in defense of civil liberties can typically point to historical instances when the infringing of one right led to the eventual loss of much more.  If you’re looking for medical examples and can’t resist gawking at a fight, read up on natural childbirth and the hazards of unnecessary interventions–though be warned that bear-baiting and cock-fighting are more genteel.

In both these cases and others like them, very few will hold to an absolute position.  We can think of situations in which, say, a government evoked emergency powers and totalitarianism did not ensue; even those who warn most stridently against unnecessary medical interventions are generally in favor of their use when truly indicated.

Additionally, because situations involving human beings are often complex, we might invoke what seems to be evidence of a slippery slope while acknowledging that other factors also have a bearing on the outcome.

Thus in debate we might see what might be considered a legitimate use of a slope-type reasoning, in combination with other arguments.  The worthy opponent will then have to resist the urge to create a straw man.  It’s tempting to argue against the cliff when our friend is only speaking of a hill.

File:Bonifacio falaises Grain de Sable.jpg

Photo: The cliffs of Bonifacio, Corsica, France, with the rock so-called the Grain de sable (the “Grain of sand”) by: Myrabella, via Wikimedia Commons


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