Three reasons slippery slope arguments are stupid:
1. Slippery slope arguments make you look like you can’t articulate a proper argument against what’s actually being discussed. “Why is this bad? Because it could lead to something bad happening.”
2. You can use them to say pretty much whatever you want:
If we allow straight people to marry, what next? Gay people wanting to marry too?
If we allow blacks and whites to marry, what next? Gay people wanting to marry too?
If we ban gay marriage, what next? Banning straight marriage?
If we let gay people raise kids, what next? Letting single parents raise kids?
If we make alcohol legal, what next? P?
If taxes on cigarettes go up, what next? Taxes on rich people going up? (I wish!)
If we change the time-honoured tradition of modern Western marriage, what next? Changing the time-honoured traditions of drink-driving and domestic violence?
If we eliminate gender restrictions on marriage, what next? Elimination of gender inequality in straight marriages?
If gay people are allowed to marry, what next? Elimination of alienation, victimisation and mental health issues among gay youth?
If gay people are allowed to marry, what next? I might have to buy them a wedding present?
3. Slippery slope arguments understand a change through a constructed narrative, rather than looking at the specific phenomenon and the actual history of change.
Swift recourse to slippery slope arguments implies that the only lens through which you can understand something is in part of a broad category of “changes to ‘traditional’ marriage” or “strange new developments” or “things my pastor told me God doesn’t like.”
This is actually a serious moral deficiency insofar as it displays a lack of ability to analyse the specific significance of something and how it affects people and society. So gay people in loving, mutual relationships are equated with sex addicts, paedophiles and men who have sex with dolphins.
Worse, proponents of slippery slope arguments project their own failures of moral imagination onto their opponents. Instead of listening and responding to the actual arguments of those who are arguing for (e.g.) gay marriage, they caricature their opponents’ moral logic into a simple reverse of their own: I want to preserve ‘traditional’ marriage. Therefore, You want to change ‘traditional’ marriage.
But “changing ‘traditional’ marriage” probably isn’t the best way of explaining the history of gay rights, and there’s certainly no alliance of polygamists and cousin-marriers plotting with gay people on what their next blow against ‘traditional’ marriage will be. If there’s any plotting, it will be about how to further increase the rights and respect of LGBTI people (see second-to-last statement in #2 above).
Of course, the increasing focusing of morality around individual freedoms, developing throughout (post-)modernity, may have something to do with the increasing support for LGBTI rights. (Or with why the marriage rights of individuals is a more important moral issue to most NZers than our ballooning economic inequality.) But individualism/liberalism can’t account for the entirety of the motivations and arguments for gay marriage. Moreover, the recent law change is the removal of a gender restriction, not a liberalisation of relationships.
Anyway, the trend towards individualism/liberalism doesn’t just mean “changes to ‘traditional’ marriage.” It’s just as much ‘to blame’ for the rise of the nuclear family, freedom of religion, and freedom to publish verbal diarrhoea about slippery slopes on the internet. Where were the slippery slope arguments then?
Two occasions where modified versions of slippery slope arguments might be OK:
1. Pointing out the logical implications of people’s assertions. This isn’t really a slippery slope argument so much as an examination of the wider scope of someone’s moral logic.
For example, if someone says “I think everyone should be allowed to marry whoever they want, so long as they consent” you can respond “So a brother and sister should be allowed to marry?” or “So one woman should be allowed to marry three men and a consenting goose?”
In which case the response is either, “Yes, I suppose you’re right, I’m happy to let people do what they want” or (more likely) “Hmmm, no, I’ll rephrase. I mean everyone should be allowed to marry whoever they want, so long as they consent and so long as it doesn’t harm them or others.”
And then – and here’s the important part – you get into a more constructive debate about which relationships we should see as inherently harmful, and why… and each case can be examined separately.
Of course this requires actually listening to what someone is saying and analysing their moral logic. For example, If someone’s moral logic is “I believe most people should be encouraged to enter healthy, lifelong, supportive marriages with people they love, and I don’t believe any particular gender roles are necessary components of a healthy marriage” the implications are going to be quite different to the liberal-permissive logic often assumed by slippery-slope proponents.
2. When there is an actual connection between what’s happening now and what might be the logical next step… and where the current step would actually make it easier for the next step to happen.
This is particularly useful if what is happening now is generally seen as harmless, but what might happen in the future is not. In this case, a slippery slope argument could form part of a range of considerations, showing that the consequences of what is happening now may be wider than people may think.
A good example might be expanding the powers of the GCSB. Even if you support some functions of the GCSB, we all know that all-encompassing Big Brother-esque powers is going too far, and it’s difficult to know where to draw the line. Since we can observe an international process of increasing powers of surveillance agencies and reducing human liberties and privacy, particularly since 9/11, it makes sense to call place the current GCSB bill in this context and let possible future developments enter into our considerations. (In fact, maybe we should have thought more about these ‘slippery slopes’ when the GCSB first opened, or when the Terrorism Suppression Act was passed, etc.)
Obviously, this is very different to gay marriage / polygamy etc. The connections are a lot closer, and the various ‘steps’ are a lot more gradual and difficult to examine/evaluate separately. Moreover, since the laws are complex the process is a lot easier to understand than the individual developments – again unlike gay marriage.