A Case against a Conservative Case against Gay Marriage, Pt. 2

Continuing my assessment of a conservative case against gay marriage. Part 1 here.

(3) There really is a slippery slope here. Once marriage has been redefined to include homosexual pairings, what grounds will there be to oppose futher redefinition — to encompass people who want to marry their ponies, their sisters, or their soccer team? Are all private contractual relations for cohabitation to be rendered equal, or are some to be privileged over others, as has been customary in all times and places? If the latter, what is wrong with heterosexual pairing as the privileged status, sanctified as it is by custom and popular feeling?

I have no problem with people marrying their sisters. The ponies case raises questions of consent and animal rights. It has been argued that polygamy has undesirable externalities and the same may be true of polyandry, so I'm not so sure about marrying soccer teams. Frankly, I prefer to simply declare the last two cases are beyond the scope of this blog post.

"Slippery slope" arguments are inherently weak. They have the following structure:

1. It is proposed that X should happen.

2. If X happens, then Y will (be more likely to) happen.

3. It is bad if Y happens.

4. Hence, it is bad if X happens.

This is a nice trick to put some additional burden on the proponents of X; now they're also asked to argue in favour of Y! There are two ways to counter this. First, you may say that if X makes Y more likely, then the time to argue against Y is when Y is actually being discussed. Second, you may attack the accuracy of the empirical statement in 2. Germany made same-sex marriages legal a few years ago. We sure love our soccer, but the let's-make-marrying-soccer-teams-legal movement has not yet materialized.

As for the second half of point (3), see comments on (1) and (2).

(4) If you have a cognitively-challenged underclass, as every large nation has, you need some anchoring institutions for them to aspire to; and those institutions should have some continuity and stability. Heterosexual marriage is a key such institution. In a society in which nobody had an IQ below 120, homosexual marriage might be plausible. In the actual societies we have, other considerations kick in.

Let's try to reconstruct the argument:

1. One can usefully distinguish an underclass from the rest of society.

2. This underclass consists (mostly? exclusively?) of low-IQ people. (It remains unclear whether you can be low-IQ and not a member of the underclass. Is the underclass defined as people whose IQ is below a certain threshold? And is that threshold 120? That's one large underclass you have there.)

3. These people "need" "anchoring institutions for them to aspire to".

4. These institutions "should" display "continuity and stability". I suppose the author means to say that if they don't, they can't get the anchoring job done.

5. Hence, let's keep marriage heterosexual so that it can do the anchoring job.

The author never says what it means that those people "need" their institutions. What happens if they don't get them? Crime? (In fact, IQ is a poor predictor of criminality.) Alcoholism? Loss of general satisfaction with life?

In other words, if the author made an argument, I might be able to respond to it, but he doesn't.

Third and final part soon.