Is the Slippery Slope "fallacy" really a fallacy?

The Slippery Slope “fallacy” seems to actually hold true in real life in some instances.

Take Adolf Hitler’s aggression in WWII, for instance. Back before Hitler annexed the Sudetenland, if someone had said, “If you let Hitler annex these small pieces of territory that he’s demanding now, he’ll follow it up later on by invading Poland, France, Russia and a lot of other countries,” he would have been accused of invoking the Slippery Slope fallacy. And yet that’s exactly what happened.

In business negotiation, politics, war, economics, social issues, etc. - aren’t there many times when the Slippery Slope fallacy is actually true in real life?

It’s well known that if there is an actual slipper slope that can be shown to exist, then it’s not a fallacy. Link.

Did you mean to post this in GQ? There really is no debate.

It’s like “appeal to authority”. If the person is an actual authority on the subject, then it’s not a fallacy. But if I invoke Einstein to “prove” that school vouchers are good public policy, then it’s a fallacy. Einstein was a brilliant physicist, but he was not a political scientist.

We have had this debate before and I tend to agree with you. The Slippery Slope is not only real, it is an effective political tactic that is regularly used by all sides.

The response is usually that the fallacy is assuming that small movement in one direction inevitably lead to much bigger ones later. That is true when taken literally for mundane things but it isn’t true often enough politically to label it a true fallacy for any given topic without other evidence. Therefore, it is not a very useful term on its own. Rather, it is more often a way to try to discredit other people’s analyzes in an intellectual sounding but vapid manner. That isn’t to say that either side is right or wrong - it could be either but it takes as much information to determine that as it did before the so-called fallacy was ever mentioned so it adds nothing.

There really are a whole lot of people that want to effectively ban abortions, guns, junk food, smoking, risky sports, religions that they don’t like and everything else and they know that they can’t do it all at once but they might be able to accomplish their goal if they take smaller steps over time. Both Progressives and Conservatives, not just in the U.S., but worldwide use versions of that tactic as a major part of their playbook.

That is the reason I don’t think the Slippery Slope label is useful unless it is used for something ridiculous and mundane. It is like calling someone paranoid when there really are a lot of people out to get them.

But if we admit the slippery slope fallacy is true then we’ll have to admit all logical fallacies are true, debate will break down, we launch the nukes, and civilization collapses. I don’t want to hunt mutant squirrels.

It’s a fallacy* if you cannot establish* a credible slippery slope actually exists*. If you can, then it’s not a fallacy.

This is a factual issue, not a debate. It’s part of the definition of the “fallacy”.
*A logical chain of events that has a reasonable probably of actually happening. Not just some claim that such a slope exists.

That is a pretty good example of a real Slippery Slope argument but that isn’t how people typically use it in common practice especially among people that use it the most. What if you were a smoker objecting to not being able to smoke at your work desk anymore circa 1993 and complained that pretty soon you wouldn’t be able to smoke anywhere in the building anymore and probably not even on the street in some places in 15 years? When someone screams that you are just a fuzzy headed victim of the Slippery Slope fallacy, what does it mean when it turns out you were right all along? Fallacy and absolutely correct aren’t very compatible terms especially when that was the real intent all along.

That’s the crux. Due to factionalism and shifting Overton windows it’s difficult to tell if it was the plan all along or the more extreme faction overtook the other over time. If you prove someone has an ulterior motive it’s just one person out of millions. Opinion polls say one thing today, another in 10 years.

Take guns. This is probably where I see the slippery slope argument used the most, by gun people. Some establishment Dem politician or moderate opinion leader will say oh, of course we don’t t want to ban or confiscate guns, that’s a ridiculous conspiracy theory. We just want sensible gun control legislation. Maybe, but they don’t speak for me, or for a lot of other libs who would like to do just that and make America be more similar to Europe or Japan. Repeal the second amendment for all I care. So to me gun people are 100% correct, strategically speaking, to be obstinate and not budge an inch.

Sometimes, there isn’t actually a “slope” at all, but a changing set of demands.

The early gay rights movement never expected to get gay marriages approved by the Supreme Court. They’d have loved it, but it wasn’t something they ever would have thought to ask. Simply removing laws against gay sexual behavior was their goal at the time.

Success in that led them to the optimism to ask for anti-discrimination laws, and success in that led them to ask for marriage rights.

There may be the appearance of a slope, but the fact is that the issues arose independently. Their succession makes it appear as if there were an “agenda” from the beginning, but there never was.

With gun-control, or abortion restrictions, there’s a much better argument for “they really want to ban it/them completely and are taking small steps.” But with some other incremental policy changes, the argument is wrong.

Supporters of the Equal Rights Amendment were accused of wanting unisex bathrooms. That was a slippery slope fallacy.

They’re only correct if the slope actually is slippery–that is, if any movement toward gun regulation makes additional movement toward gun regulation easier. And the problem is that it obfuscates what should be the discussion, namely, will this particular piece of legislation, whatever it is, improve public policy?

Of course people are capable of evaluating different pieces of legislation discretely and as individuals. Marshmallow, you may be all about banning all firearms, but that doesn’t mean that Hillary Clinton has the same views. Nor does it mean that Hillary Clinton, though she might favor limiting gun purchases to five per month per individual, would also vote for banning private ownership of handguns.

The slope here, and elsewhere, is not slippery, and acting as though it is makes it harder to improve public policy.

But it needs to be true most of the time, not just occasionally, for slippery slope to be an argument.

A slippery slope is an inclined surface coated with a lubricating substance. An object allowed to move from one end will inexorably slide toward the opposite extreme pulled along by gravity.

But a metaphorical slippery slope is floating around in space where isn’t necessarily any analogue to gravity. There needs to be some impetus that would drive some small change toward some extreme set of conditions.

The OP’s Nazi example is the “exception that proves the rule” IMO. The conditions that allowed Hitler to take power and launch a world war were complex and unique and yet this example get cited over and over again.

I can think of a couple of examples of actual slippery slopes: In the 1960’s, loosened public attitudes on premarital sex and drug use triggered an epidemic of this sort of behavior that led to a fairly severe set of social problems. The impetuses (impeti?) here are human’s natural desire for sexual or chemical gratification and their addictive nature. Fallacy of the excluded middle.

But it’s harder to think of examples where a slight tightening of rules or laws led inexorably to ever more restrictive ones being passed, because opposition builds up while support falls away.

Right. Unlike in war where every defeat degrades one side’s ability to carry on, in politics you live to vote again, and defeat can really galvanize the opposition.

I don’t see why it matters if there’s an agenda or not. It’s easier to prove there’s a potential slope if you can show one side has ulterior motives, but usually social movements are way too big and span too much time (decades, centuries) to be controlled by only a couple individuals. Again, it’s the Overton window. Once progress is made at what previously seemed unlikely, groups who want to push even further will find a more receptive audience. Former liberals become conservatives, former radicals become liberals, etc.

Right. I’m saying, and the OP is too I think, is that it’s difficult to make this determination beforehand because predicting the future is hard. Things are obvious in hindsight.

That’s a good one since it can be used at any point down the slope.

That’s what I said.

Given liberal opposition to guns and liberal romanticism of anti-gun countries as mentioned I’m not sure what makes you so confident.

Are there any slippery slopes, in your view? Is it in the eye of the beholder? Do slippery slopes have a bad reputation? I’d say a lot of positive social changes are the result of slippery slopes, and the opposition correctly identified and predicted said slopes, but maybe I’m applying the term too broadly.

Any proposal I don’t like is a slippery slope towards annihilation of our universe and the multitude of all possible universes. When a proposal I like is called a slippery slope then it’s a fallacy.

Something can be a fallacy even if it’s often true. Slippery slopes do exist, they are just used in arguments a lot more often than is justified.

Gun control and the death penalty tend to be slippery slopes. In countries where guns are sharply restricted, pepper spray and stun guns tend to be outright illegal. In countries where there is no death penalty, life sentences have often been eliminated as well.

So in the US, the Sentencing Project is already working on that front, even before we’ve gotten rid of the death penalty!

Another example is the response to Citizens United. I went round and round with people all over the internet on the issue, and most of them said, “Corporations don’t have the right to spend unlimited amounts of money on campaigns! But individuals do, of course!” Of course. Except once individuals started actually doing it, then suddenly that became “not a right”. That’s two lengths down the slope. At what point do we allow elections to be “unduly” influenced and decide we can’t impose restrictions? We say that we’d never ban books now, but what happens if we’ve banned TV ads and books become the primary method of influencing elections? Slippery slope not a fallacy.

IMO, the best way to detect a slippery slope is when the person advocating a particular view cannot articulate a limiting principle, or see the problem as all important to solve and what methods used to solve the problem as less important.

If that’s the case, the slope goes up, not down. There’s no such thing as a set of legislation, each part of which individually makes things better, but the whole set makes things worse.

I think that you’re applying the term in a pretty unconventional way, if slippery slopes lead up.

That’s it in a nutshell.

If you want to argue that a particular proposition poses a marked danger of something really bad happening down the road, you need more evidence than “this is a slippery slope”. Otherwise it’s just a scare tactic and a recipe for helpless inaction.

First of all, let’s be perfectly clear: someone can use logically unsound arguments and still end up being correct. Let’s say I wish to argue that the Straight Dope is the best message board in the world: if I start saying that that the Dope’s nearest competitor is owned by a pedophile priest, I have argued an ad hominem. But improper argument does not necessarily mean that my proposition is wrong; it means that I’m throwing up garbage in support of my point.

What you’re essentially arguing is that because someone was demonstrated to be correct using an illogical slippery slope argument, that the slippery slope argument tactic is not illogical because its proponents ended up being right.

So returning to my hypothetical: I argue that the SDMB is the best based on an ad hominem. I end up being proven categorically correct that the Dope is aces, tops, the bee’s knees. Does that mean that ad hominems are sometimes proper arguments?

It is really a fallacy when it is the only evidence you have to argue against a specific position.

You assert that A leads to B leads to C.

You have no argument against A, which is a perfectly reasonable position that others are proposing evidence to argue for, but you DO have evidence that C is bad. You therefore propose that the slippery slope to B and C is therefore evidence enough that we shouldn’t allow A. If the opposite side can argue both that A is a reasonable position, and that A would NOT inexorably lead to B and C, they can call out that argument as a slippery slope fallacy and thereby refute it. If you can’t come up with a sufficient argument against A itself (not just against C), then you lose.

I would put it more simply: it’s a fallacy when no good arguable reason is provided as to why A will invariably lead to B and then to C.

The longer the logical chain of assumptions, the more obvious that an informal fallacy is being used. What the fallacy accomplishes, is hide the debatable assumptions that must be accepted on the road down the “slope”.

I don’t see anyone in this thread making a case that the Slippery Slope argument is a fallacy. A lot of people have suggested reasons that it could certainly be wrong in a given instance, which is certainly true, but so could any other form of argument.

The relevance is that if someone makes a slippery slope argument, you can’t just wave it away by saying “that’s a slippery slope fallacy” (as is commonly done) but have to demonstrate why in this case the slippery slope argument fails.

I don’t understand this argument. What difference does it make what the mechanism is?

Suppose we’re currently at Point A, and there’s a fight over whether to change to Point B. Supporters of Point A are arguing that while the change to Point B itself is OK (or not terrible, anyway), but it will inevitably lead to Point C, and Point C is far worse than Point A. What difference does it make whether the slide to Point C is due to a nefarious scheme by Point B supporters, or due to some other dynamic? The equation is the same: Point A is better than Point C, so we should not switch to Point B because this will inevitably lead to Point C.