# Is the slippery slope argument just another reductio ab absurdum? **URL:** \ **Category:** Great Debates\ **Created:** [April 2, 2013, 12:25pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618 "2013-04-02T12:25:45Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![pseudotriton\_ruber\_ruber](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@pseudotriton\_ruber\_ruber](https://boards.straightdope.com/u/pseudotriton_ruber_ruber)\ **Post date:** [April 2, 2013, 5:10pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/21 "2013-04-02T17:10:34Z")
> [@astorian](#): > > Now you’re being obtuse. I have just demonstrated that, in the past, people who predicted that Elvis/rock and roll would surely lead to a breakdown in sexual morality. Did they know the EXACT course those changes would take? Of course not, but they saw Elvis and rock as threats to traditional morality. And they were right. Everything they feared would happen DID happen, and then some. > > Now, you’re saying, in effect, “So what?” Unacceptable. > Let’s get YOUR position(s) straight. > > 1. Do you believe that marriage is supposed to be permanent? > > 2. Do you believe that promiscuity and divorce are bad things? > > 3. Do you believe that the traditional rules of marriage (including the prohibition of divorce and adultery) should apply to gay married couples? > If you DO believe in these things, we have a lot to talk about. If you DON’T (and I’m 99% sure you don’t), then we have absolutely nothing to talk about. > > I really want to know if you’re saying, “Slippery slope arguments are absurd, and all the the bad things people predict will NEVER happen”? Or are you saying, “All those allegedly bad things the slippery slopers are predicting probably WILL happen, but I just want them to shut up anyway, because I think those are actually GOOD things”? Let me try again. I’m agreeing broadly that people who predicted Elvis’s performance would lead to looser standards in sexual latitude throughout society generally were right BUT 1. these were the same people who saw lots of things leading to dangerously loose standards–hula-hooping was seen as lascivious, for example. 2. these were the same people who saw lots of things that I consider positive goods as leading to dangerously loose standards–work on the birth-control pill, for example, had much more than Elvis did to lead to loose sexual standards, but they DIDN’T much complain about it because it wasn’t so easy to know what was going on behind laboratory doors. 3. These people were mainly jerks making a jerky argument–“Shit is gonna happen! And some of it will suck!” is how they would phrase it, if they talked like that. Not terribly profound. By that argument, they’re always going to be right about SOMEthing. ---
**Author:** ![astorian](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@astorian](https://boards.straightdope.com/u/astorian)\ **Post date:** [April 2, 2013, 9:51pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/22 "2013-04-02T21:51:16Z")
If you’re going to dismiss demonstrably correct predictions because you dislike the source, here’s a different question: why is it that everyone who’s argued for years that “marriage is just a piece of paper” now thinks allowing gay marriage is absolutely crucial? ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [April 2, 2013, 10:02pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/23 "2013-04-02T22:02:24Z")
> [@BrainGlutton](#): > > RatonalWiki is really into this sort of thing. > > [Slippery slope:](http://rationalwiki.org/wiki/Slippery_slope) > > [_Reductio ad absurdum:_](http://rationalwiki.org/wiki/Reductio_ad_absurdum) I’d be really careful about using RationalWiki. It is not nearly as well sourced as regular Wikipedia on the same topics. > **[Slippery slope](https://en.wikipedia.org/wiki/Slippery_slope)** > > In a slippery slope argument, a course of action is rejected because the slippery slope advocate believes it will lead to a chain reaction resulting in an undesirable end or ends. The core of the slippery slope argument is that a specific decision under debate is likely to result in unintended consequences. The strength of such an argument depends on whether the small step really is likely to lead to the effect. This is quantified in terms of what is known as the warrant (in this case, a demon > **[Slippery slope](https://rationalwiki.org/wiki/Slippery_slope)** > > While not a logical fallacy in itself, the slippery slope is a common variant on the argument from adverse consequences that asks for a prohibition or curtailment on something based on a series of undesirable results. This usually involves many... ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [April 2, 2013, 10:46pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/24 "2013-04-02T22:46:27Z")
> [@John\_Mace](#): > > Yeah, the slippery slope argument is about incremental change that is, if not inevitable, then likely. As any cite will tell you, it’s only a fallacy when no such slope actually exists. But sometimes it does. > > Imagine if someone had baulked at NYC’s original trans fat ban by claiming we would see the banning of large sized sodas. It would have been poo-hoo’ed away as a slippery slope fallacy. I think there is a difference between the argument that allowing A will lead to allowing B and the argument that proponents of A are also for B, and letting them win A will strengthen their position with respect to B. Your example seems more of this type. Another example might be “banning abortion will lead to the banning of all forms of birth control.” I don’t think there is a direct connection, but many abortion opponents seem to be birth control opponents (in the leadership ranks, anyway) and letting them win one will let them turn their attention to the other. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [April 3, 2013, 2:00am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/25 "2013-04-03T02:00:57Z")
> [@](#): > > Is the slippery slope argument EVER valid? Ever? Of course. No debating tactic is ‘ever’ completely wrong all the time in every instance. Always? Of course not. Sorry, you still have to do the work of refuting an argument, even if the person is saying it’s a slippery slope, depending on if they back it up with more than just stating it’s a slippery slope. [QUOTE=pseudotriton ruber ruber] Let me try again. I’m agreeing broadly that people who predicted Elvis’s performance would lead to looser standards in sexual latitude throughout society generally were right BUT [/QUOTE] BUT…stop right there. You’ve just answered the question you actually asked in the OP. If the people who made the theoretical (I’m sure someone made it at some point) argument that Elvis and rock and roll music would lead to looser sexual standards and simply said it was a slippery slope, then while it turned out they were (sort of kind of) correct they didn’t make a very good argument, and it was a fallacy to use it that way. If they backed it up with some sort of additional data and some sort of rationale as to WHY it was a slippery slope, then it wasn’t a logical fallacy…and, in fact, they were sort of kind of correct. It all depends on the argument made and how they used their assertion it was a slippery slope as to how convincing their argument was. ---
**Author:** ![Oly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/oly/32/8255_2.png) [@Oly](https://boards.straightdope.com/u/Oly)\ **Post date:** [April 3, 2013, 2:45am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/26 "2013-04-03T02:45:33Z")
The thing that bothers me about the SSA is that it assumes, and in fact demands, that people are helpless once the supposed first step or “slip” happens. In the analogy of the slope it’s gravity, a force of nature, that takes control once “solid ground” is lost. And that’s just how SSA-ers try to lay it down - that there’s some sort of natural law that will be unleashed and force us to irreversibly slide down a slope into some pit. There is no natural law that requires the “worst” to happen. We do have some control over that. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [April 3, 2013, 3:12am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/27 "2013-04-03T03:12:31Z")
**Astorian** , people who predicted that Elvis dancing on TV would _lead to_ the various other things you mention were wrong. Elvis dancing on TV didn’t cause any of those other things. Rather, they were all part of a single phenomenon. Stopping Elvis would have stopped nothing else. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [April 3, 2013, 3:13am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/28 "2013-04-03T03:13:30Z")
> [@astorian](#): > > If you’re going to dismiss demonstrably correct predictions because you dislike the source, here’s a different question: why is it that everyone who’s argued for years that “marriage is just a piece of paper” now thinks allowing gay marriage is absolutely crucial? Anyone who seriously made that kind of argument is an idiot, I feel compelled to note. ---
**Author:** ![sqweels](https://avatars.discourse-cdn.com/v4/letter/s/f19dbf/32.png) [@sqweels](https://boards.straightdope.com/u/sqweels)\ **Post date:** [April 3, 2013, 5:35am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/29 "2013-04-03T05:35:57Z")
IMO, the example that best illustrates the reducto ad absurdum fallacy is the basic anti-abortion argument: If a newborn infant counts as a person, why wasn’t it a person the day before that given that it’s only slightly more developed. And therefore, why not the day before that and the day before that until we get to the absurd notion that a fertilized embryo is a person. As for the slippery slope, it’s only valid in specific cases where there’s an impetus to go to the extreme. In the 1960s, relaxed social mores regarding drug use and sexual activity led to rampant heroin addiction and pregnancy/STDs because of the powerful impetus on the masses of people to get high and have sex in the absence of social restrictions. But there’s no mass impetus to gay marry. It only applies to a strictly finite segment of the population. As for the Holocaust and Communism, these extremist outcomes were not simply led-to be previous events. The impetus was the determination of the extremist faction to fulfill its established radical agenda, and became rare and oft-cited examples in succeeding. ISTM hat the slippery slope and reducto ad absurdum arguments are opposites in that the former accuses your opponent of extremism, the latter is employed by extremists themselves. So the SSA could be, “A little bit of socialism will lead to a lot of communism”, while the RAA would be, communism is bad, therefore even a little bit of socialism is a little bit bad, therefore let’s have zero social safety net". ---
**Author:** ![JLRogers](https://avatars.discourse-cdn.com/v4/letter/j/ce73a5/32.png) [@JLRogers](https://boards.straightdope.com/u/JLRogers)\ **Post date:** [April 3, 2013, 11:42am UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/30 "2013-04-03T11:42:17Z")
> [@pseudotriton\_ruber\_ruber](#): > > Lately, I’ve been exposed to all sorts of argument-ending slippery slope arguments: if you let gays marry, then why not cats and dogs? This is a [_non sequitur_](http://en.wikipedia.org/wiki/Non_sequitur_(logic)). > [@pseudotriton\_ruber\_ruber](#): > > If you ban private ownership of bazookas, then they’re coming in the black helicopters to seize your handguns, etc. This is a [strawman](http://en.wikipedia.org/wiki/Strawman) at best. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [April 3, 2013, 1:33pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/31 "2013-04-03T13:33:37Z")
> [@Frylock](#): > > **Astorian** , people who predicted that Elvis dancing on TV would _lead to_ the various other things you mention were wrong. Elvis dancing on TV didn’t cause any of those other things. Rather, they were all part of a single phenomenon. Stopping Elvis would have stopped nothing else. I still think it’s a valid argument to say “once we abandon our strict moral standards (by letting Elvis dance on TV), then there’s nothing preventing X”. IOW, once the zero-tolerance censorship was loosened, what new limiting standard was put in it’s place, other than a subjective “that’s not so bad”? ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [April 3, 2013, 2:26pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/32 "2013-04-03T14:26:11Z")
> [@Lumpy](#): > > I still think it’s a valid argument to say “once we abandon our strict moral standards (by letting Elvis dance on TV), then there’s nothing preventing X”. IOW, once the zero-tolerance censorship was loosened, what new limiting standard was put in it’s place, other than a subjective “that’s not so bad”? But that’s not a slippery slope argument. Maybe this is just a nitpick. Moreover it’s still not really a good argument (though as I usually find in practice, I think there’s usually a _valid_ argument lurking unexpressed behind all the bad arguments.) Failling to follow rule x doesn’t mean there’s no rule to follow. Here’s the best way I can think of to put the sentiment. “I thought we were going to follow rule x. Apparently not. So now either there’s no rule, or there’s some rule y I’m not aware of.” This is an invitation to articulate rule y. Then the objector might insist x is better than y of course. But we’re away from the slippery-slope looking discussion we had before and that’s progress. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [April 3, 2013, 3:03pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/33 "2013-04-03T15:03:59Z")
> [@Frylock](#): > > Here’s the best way I can think of to put the sentiment. “I thought we were going to follow rule x. Apparently not. So now either there’s no rule, or there’s some rule y I’m not aware of.” This is an invitation to articulate rule y. Then the objector might insist x is better than y of course. But we’re away from the slippery-slope looking discussion we had before and that’s progress. I think that says it perfectly. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [April 5, 2013, 1:39pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/34 "2013-04-05T13:39:02Z")
> [@pseudotriton\_ruber\_ruber](#): > > Let’s consider banning slavery. It’s nearly 1850, and I keep hearing that if you free the slaves, the next thing you’ll be seeing is widespread misegenation… I would say this is a better example that the slippery slope actually exists. Miscegenation wasn’t the _next_ thing, but it was perhaps an inevitable consequence. So maybe the real questions are: how slippery, and how steep, is the slope? ---
**Author:** ![pseudotriton\_ruber\_ruber](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@pseudotriton\_ruber\_ruber](https://boards.straightdope.com/u/pseudotriton_ruber_ruber)\ **Post date:** [April 5, 2013, 2:13pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/35 "2013-04-05T14:13:21Z")
OK, but my point there (I think) was primarily that if someone from 1850 is objecting to changes that won’t be take effect for another century or so, he doesn’t get a vote. You get to complain about consequences that are immediate and definite, not ones that are speculative and far-off. (I knew “misegenation” didn’t look right.) ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [April 5, 2013, 2:22pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/36 "2013-04-05T14:22:28Z")
> [@pseudotriton\_ruber\_ruber](#): > > OK, but my point there (I think) was primarily that if someone from 1850 is objecting to changes that won’t be take effect for another century or so, he doesn’t get a vote. You get to complain about consequences that are immediate and definite, not ones that are speculative and far-off. > > (I knew “misegenation” didn’t look right.) I disagree with this. It is perfectly acceptable to support or be opposed to a law or policy because you fear long term consequences. For instance, many people support legislation intended to reduce global warming, though the impact of the warming will likely not have its most serious consequences during their lives. Won’t anyone think of the CHILDREN??!! 😛 ---
**Author:** ![astorian](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@astorian](https://boards.straightdope.com/u/astorian)\ **Post date:** [April 5, 2013, 6:42pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/37 "2013-04-05T18:42:28Z")
Fundamental question: when an opponent of gay marriage says, “If we allow this, it’s inevitable that polygamy will be legalized,” is your reply, “That will never happen, and you’re being ridiculous to suggest it ever will”? Or is it, “It may very well happen, and you know what? I’m FINE with that”? ---
**Author:** ![pseudotriton\_ruber\_ruber](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@pseudotriton\_ruber\_ruber](https://boards.straightdope.com/u/pseudotriton_ruber_ruber)\ **Post date:** [April 5, 2013, 8:55pm UTC](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618/38 "2013-04-05T20:55:14Z")
There’s a difference, I think, between “Prolly won’t after me or my generation, but some future generation’s going to have to think how they feel about it” and “Prolly won’t affect me or my generation but some future generation’s going to have to live inside a toaster-oven.” [Previous page](https://boards.straightdope.com/t/is-the-slippery-slope-argument-just-another-reductio-ab-absurdum/654618.md?page=1)