Slippery Slope Discussion

The SlipperySlope page featured a controversial example I heard in a American documentary about same-sex marriages, shown on MTV. It went:
"If we allow two men to marry each other, we'll have to allow marriage for other relationships as well, and we'll get polygamy, bestiality or even people marrying their car."
I presented this as an example of a SlipperySlope type argument, in this case against same-sex marriages. I should've chosen another example, because much discussion ensued... I still feel it is an example of a LogicalFallacy, especially since there are two directions to go from 'standard' marriage, being polygamy and same-sex monogamy, and neither position seems to be an extension of the other. I feel same-sex marriages should be allowed, and I live in a country (TheNetherlands) that does. I'm not sure about polygamy, since I fear that might lead to inequality within the marriage. Then again, equality isn't assured in regular marriages either, so that's not a valid argument against polygamy per se. Of course, I'm talking about legal marriage here. Some churches allow one, some the other and lots neither, and I don't see why anyone would want to join a religion that doesn't recognize his or hers own marriage, so we'll have Freedom of Religion in both senses - everyone is free to believe what they want, and everyone is free to change their believes. Change your Religion or Change your Religion.

Concerning the SlipperySlope itself, we may agree that they do exist.
"You give an inch, they take a mile."
But the mere existence of the slope is insufficient as an argument against taking some of the steps. Slipping down the slope is not inevitable; we're able to stop anywhere on the slope. And that is why the SlipperySlope is a logical fallacy. -- AalbertTorsius (ATS)

I liked your comments Falk (FalkBruegmann was listed a contributor, Bruce mistakenly ascribed my (ATS) comments to him), when we are dealing with human behavior, there is always quite a spectrum of outcomes that could result from action A. The term SlipperySlope is usually used in discussions about choosing to allow a behavior that is a step in a direction that most people don't want their society to move into (like increased taxes or looser social mores). The phrase is declared because we have observed human behavior long enough, have seen the tendencies latent in Humanity, and can usually predict the outcome of taking the debated step. Mankind, by nature, abhors restrictions on behavior. We rebel against them from birth. Yet, Mankind tends to anarchy without them. Loosening a social norm (like gay marriage) redraws the "social line in the sand" to include people who's desired behavior is currently outside the line. Once the line is redrawn, the next person whose behavior is just a little further down the bell-curve (NAMBLA, professional men who want to have sex with 16 year-and-above boys), polygamists (already filing legal cases to nullify current convictions), etc will come knocking at the door. It is predictable human nature. And America has reached a point where people value individual freedom over societal welfare. -- BrucePennington

As the one who made the comments about marriage, above, I'd like to react. First of all, I gave it as an example, without wanting to get in to the debate - I guess I should've chosen another example. Having said that, and living in a country that does allow same sex marriage, I agree that it may be a slope of some sort, but not a very slippery one. It's rather a number of discrete steps. One of them is marriage between one man and one woman. Another one is marriage between two people. Another one is marriage between any number of people. If you take one step, you don't have to take the next. And don't bring in sex with minors, that's a StrawMan. -- AalbertTorsius

OK, but "a number of discrete steps" is just another way of describing the SlipperySlope. When viewed up close, you can see each "discrete" step. When viewed from long-term social history, you can see the "slide." You bring in a couple of interesting concepts. You say we are living in a country that does allow same sex marriage. I would refine that to: We are living in a country where a state allows same sex marriage. It is not nationally accepted. The other point: "If you take one step, you don't have to take the next." While this is clearly true, as my point makes above, observations of past and current human social behavior would lend a prediction that we will head down the "slope" if we don't make a conscious effort to stop it. In an interesting example, a gay supporter of same sex marriage on a radio interview, was against allowing polygamous marriage, but couldn't give any rational or legal reasons to disallow it. And in truth, when you move off the mark of heterosexual marriage, in any direction, you cannot support drawing the line anywhere else. Again, I agree we don't have to go there, but people already want to and are actively working to make it happen. -- BrucePennington

Rock solid logic, there. First blacks stopped being slaves, then they got to vote, and now they dominate professional sports and entertainment. Women went from being property to owning property, and one day might actually be taken seriously in public discourse. Kings let nobles have power, then nobles let commoners have power and now I can't get good help without violating immigration laws. These slippery slopes must be roughened to prevent the inevitable decline of straight white male power in the enlightened world. (Luckily savages and barbarians seem immune to this sort of thing.) -- EricHodges

Thanks Eric! You bring up a good point. The focus, here, has been on negative effects of SlipperySlope. As you well point out, SlipperySlope affects can be positive as well. -- BrucePennington

And in truth, when you move off the mark of heterosexual marriage, in any direction, you cannot support drawing the line anywhere else

No, that's not truth. It's merely an assertion, and a false one. As a counter example, I can support drawing the line at marriage being the union of two people. And I do. Your argument is exactly an example of the fallacious argument described in this page - the idea that the step away from heterosexual marriage to include homosexual marriage must inevitably lead to further steps. It doesn't have to, at all.

The fact that some people might like to allow polygamy or lower the age of consent but not allow gay marriage shows that this is an example of slippery slope as a fallacious argument. But this is offtopic for this page. We could move it away, but I suggest we just trim back to the original argument. There is also an interesting tie into MentalTotems
SlipperySlope can be the result of a lot of different logical fallacies, including ExcludedMiddle and UndistributedMiddle (oddly, "middle" means two completely different things in those two), but is essentially a fallacy of PostHocErgoPropterHoc. It can also come from rigorous and scientific induction from the supposed base causes, but those can always come from bad statistics. As the above poster said though, some slopes really are slippery, so it's not necessary fallacious in RhetoricalArgument?, but it generally is in LogicalArgument? (ultimately it's all rhetoric though, and it's bad rhetoric to rely solely on logic. Take that Mr Spock.)

I find that the slippery slope comes from a failure to fully extrapolate logic. The slippery slope does, indeed, exist - however, the proper approach is not necessarily to stay at the top, or even to worry that the slope itself exists. Take the case of gay marriage - gay marriage is directly in the middle of a slippery slope, because the underlying logic has not been fully extrapolated.

Quite obviously, there is a slippery slope there. However, if we examine the justification of why we made the decision: "it hurts no one, and helps those who wish to marry and cannot", then we can extrapolate the optimal decision that fits the justification. In this case, it is likely a law that describes a concept of marriage as occurring between a group of consenting people, where person consents to the inclusion of each other person, and a single person can only be a member of one marriage. Consent requires an adult human, so the concept excludes children, animals, etc.

In this case, the slippery slope provides an advantage: we cannot see the forthcoming problems, so as in ExtremeProgramming, we DoTheSimplestThingThatCouldPossiblyWork, which is including homosexuals. To leap-ahead to an over-inclusive concept would be risky (besides being politically complex) so we let the slope handle it. Simply reapply the test "it hurts no one, and helps those who wish to marry and cannot" at each phase. Only problem is that the justice system doesn't refactor very often, so we end up with too many laws.

-- MartinZarate

Well, the issue is of course that not all people agree with your assumptions:

This condition discriminates against those who would like to be married but do not fit the above definition. Allow[ing] same-sex couples to marry [...] hurts no one

Discriminate is a value loaded word because there are people who are upset by the existence of homosexuality. (See MentalTotems)

Your butchering of my words has completely changed the intended meaning. I don't have a problem with homosexuality. I was referring to your definition of the "problem" being that there were people who would like to marry but could not as if this were the only possible definition. Sorry about that. - I didn't mean to change the meaning of your words, I didn't think that there was any question about the existence of people who want to marry but are not allowed to. Only as to whether is is a 'problem' or not. I was trying to focus on where I saw the disagreement. I guess I don't see your alternate way of phrasing the problem? Can you explain further? How would you define the problem, with or without quotes?

Your definition of the "problem" seemed to be that people who wanted to marry could not. I think that's too general a point. I tried to say this. You seemed to assume that I meant I disagreed with the idea that homosexuals could marry, which I had not mentioned and I don't have a problem with anyway.

The issue is that the definition of the problem determines what is the "optimal" outcome. So with your definition you argue we should go further down the slope (to group marriages). With a problem statement that "this discriminates against same-sex couples" you end up with a different "optimal" decision.

Anybody willing to admit to being old enough to remember when a mixed marriage meant a protestant and a catholic?


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