A long while back, I noted that most discussions about gay marriage are more like races to who could pose one of the three tired old analogies first. The three variables are: race, polygamy, and bestiality. If you can pose the analogy first, you have a kind of dialectical advantage — even if the analogy isn’t perfect. This is because there’s a kind of defensive posture the opposition must take, once the analogy is posed — they have to answer this line of argument before they can proceed with their own, and this often takes more time and energy than we normally allot for our critical discussions. And so, for familiar structural reasons (we always have a dearth of time an energy for critical discussion), those who wield the analogy first are those who often get to claim they came out the best.
So much for the strategic argumentative elements of argument by analogy. There are a few other things to note. First, all analogies, in the end, are limited. They can find some relevant feature that’s the same, but they also must have their differences. Analogies are not identities. Second, the form of argument by analogy in this context is off of a deep principle of justice:
Treat like cases alike
The strategy with analogy is to identify the similarity between two cases and show that because we have an unproblematic precedent of treatment with one kind of case, we, assuming the deep principle of justice, treat the other case similarly. And so, if discriminating against gays is like discriminating against blacks, we shouldn’t. And if discriminating against gays is like discriminating against people who want to have sex with sheep, we should. Everything hangs on the relevant similarities between the cases, and so, everything hangs on the aptness of the similarities between the cases. And we should, being good, rational arguers, be open to the possibility that our analogies are weak and the opposition’s are strong. That happens.
Will Saletan’s post over at Salon is an exercise in this kind of argumentative humility. He takes the analogy between race and sexual orientation to be a good analogy, but he’s willing to note where there may be relevant moral differences between the two. Primarily it’s about the issue of having children.
The central, categorical objection to gay marriage is that same-sex couples can’t produce biological children together…. Just because I don’t agree with an argument, however, doesn’t mean it’s irrational. Marriage has historically been a sexual institution. A rational person can maintain that a relationship between two people categorically incapable of producing children together—that is, two people of the same sex—can’t be a marriage. That argument doesn’t justify denying them the right to love one another openly, nor does it justify denying them the benefits and honors we bestow on couples for making lifetime commitments. But it can justify a person’s refusal to accept a same-sex relationship as a marriage.
Saletan’s giving the case for disanalogy it’s due. He follows this noting:
The argument has plenty of problems. We let old people marry. We let infertile people marry. We don’t insist that married couples produce kids. We welcome adoption and stepfamilies. Gay couples can have kids using donated eggs or sperm. Many gay people are already raising children, and doing it just as well as straight people.
All of that is true. But I’d be remiss to omit the rejoinder from George and his colleagues: Sex is a much brighter line than fertility or intention to bear children. It’s certainly a less intrusive distinction to enforce.
This is now a point about legal treatment – the law isn’t about your intentions with the marriage, it’s about what can reasonably be expected in it. In this regard, it is right that the case for analogy between race and sex-orientation discrimination is weaker. But, again, analogies are not identities, and to hold them to the standard that the cases be identical is crazy.
In this respect, I think Saletan’s on the right track both argumentatively and politically to acknowledge that there may be differences between these cases. But the differences are still insufficient to break the relevance of the analogy.
At the risk of irritating John let me offer a rather inchoate thought – People raise the issue of polygamy to test your argument, to see if the argument you are making would also justify legalizing polygamy. If your argument could also be used to support legalizing polygamy than we ought to inspect it more closely, and perhaps refine it a little bit more. The slippery slope is not always fallacious.
Hi Ben, Apologies in advance for the long reply. I like your observation that often slippery slopes and analogies can be posed less as demonstrative arguments, but more as exploratory considerations. John and I have made a similar distinction with regard to tu quoque reasoning – you point out apparent cases of hypocrisy less to refute and more for the sake of asking a clarifying question. The crucial thing about this distinction is how we wield it. Especially if we think that it’s a clarifying device, we don’t want to prohibit it, but because it can (as I noted earlier in the post) serve as a strategic tool to make the other side waste their energies on something irrelevant, it has its abuses. In this respect, context matters, for sure.
And I think it’s worth making it explicit how we’ve really got two notions of ‘fallacy’ afoot here. On the one hand, we have a strict semantic notion of fallacy, which is about either truth transmission or relevance. On the other hand, we have this dialectical notion of fallacy, which is about having a fruitful discussion. We can have semantically fine but dialectically fallacious arguments, and we can have semantically fallacious and dialectically appropriate arguments. The kind of ‘exploratory’ or ‘dialectical’ slippery slopes or analogies are of the latter kind — they may, in the end be false analogies (so semantically defective), but the only way to find that out is to try them out (so dialectically appropriate).