2013-03-26

The Slipperiest Slope

The always-entertaining James Taranto flexed his logic muscles when he wrote yesterday's installment of "The Best of the Web Today." His lead item covers a recent New York Times op-ed by one Sarah Conly, who took time out of her busy schedule of writing apologies for the nanny state to... defend the nanny state!

Taranto's command of logic and irony are always impressive, but in this case, he really out-did himself. Conly  made the following argument in her piece in favor of the Bloomberg soda ban:
Do we care so much about our health that we want to be forced to go to aerobics every day and give up all meat, sugar and salt? No. But in this case, it’s some extra soda. Banning a law on the grounds that it might lead to worse laws would mean we could have no laws whatsoever.
If you're quick on the uptake, you may already see where Taranto went with his criticism. If not, I won't hold you in suspense. Here's his response:
The best part is that conclusion. Essentially she's saying that if you accept one slippery-slope argument, you have to accept all slippery-slope arguments. Therefore, slippery-slope arguments are unsound. 
Taranto goes on to call this "the slipper's paradox," but if we want to get technical, we must stop short of calling it a paradox. More accurately, it's just sloppy reasoning. The reason we cannot accept a slippery-slope argument is that, for example, hypothetical and even-more-intrusive health laws offer no direct refutation of a soda ban. What I mean is that there is nothing about a hypothetical future regulation that directly addresses the problem with a currently proposed regulation. We might venture to suggest that the soda ban may provide sufficient "jurisprudence" for a more invasive regulation in the future, and that there is value in avoiding such a mistake - and that would be a good argument against (not a logical refutation of) the proposed soda ban. But the mere possibility that some more invasive law may perhaps come along does not argue against the soda ban.

It's important to note that Conly didn't make the logically valid argument, she made the invalid one. As Taranto noted, she suggested that slippery-slope reasoning against a soda ban would lead to slippery-slope reasoning on every conceivable legal issue; i.e., a slippery-slope-slippery-slope. If Conly thinks we ought not resist encroachments on liberty, she is a poor advocate for her cause.

But I'm not exclusively interested in the logical irony of it all. I'm also interested in offering some further objections to Conly's point. Let's set aside the fact that she hasn't managed to argue her case very well and tackle her claims more directly.

The penultimate paragraph of Conly's article reveals the core belief at the heart of her soda ban views:
In the old days we used to blame people for acting imprudently, and say that since their bad choices were their own fault, they deserved to suffer the consequences. Now we see that these errors aren’t a function of bad character, but of our shared cognitive inheritance. The proper reaction is not blame, but an impulse to help one another.
Conly's argument is that nanny state regulations that, for example, prevent us from being able to engage in the "error" of drinking too much soda at once reflect an impulse to help one another. I have no real argument with that claim; I don't doubt that nanny statists have a real desire to improve the lives of their fellow citizens. No, what strikes me about this argument is Conly's belief that making choices like drinking too much soda are incarnations of a cognitive bias, a "function of our shared cognitive inheritance." According to Conly, people don't drink too much soda because they're being "imprudent," but rather because "we often don’t think very clearly when it comes to choosing the best means to attain our ends."

The general idea here is that drinkers of very large sodas are hapless products of thousands of years of human evolution. If they weren't cognitively biased, then they would never choose to drink soda. They would choose other means to attain their ends.

The question is, who is in a better position to assess what those ends are: Conly, or the soda-drinkers? Perhaps Conly is correct, and I am open to that possibility, but in order to demonstrate this, she must say something to convince me that she knows better about the ends sought by the majority than the individual members of that majority themselves. (Strangely, that majority is apparently not writing New York Times op-ed pieces about its ends. Or, are we to believe that Conly speaks for that majority? If so, why? Again, I am open to the possibility that Conly is speaking for the majority, but let us first establish that this is the case.)

To underscore this point, consider the following passage from Conly's editorial:

Is it always a mistake when someone does something imprudent, when, in this case, a person chooses to chug 32 ounces of soda? No. For some people, that’s the right choice. They don’t care that much about their health, or they won’t drink too many big sodas, or they just really love having a lot of soda at once. 
But laws have to be sensitive to the needs of the majority. That doesn’t mean laws should trample the rights of the minority, but that public benefit is a legitimate concern, even when that may inconvenience some.
So, there is no question about the fact that Conly assumes she writes for the majority. That majority is one consisting of people who are simply unable to say "no" to taking their own initiative to purchase large sodas from New York City restaurants, because their cognitive biases convince them - incorrectly - that the large soda is the best means of meeting the ends they had in mind when they decided to purchase the soda.

Does this sound like anyone you know? Do you know anyone who is unable to buy anything other than a large soda to meet specific ends, when in fact something other than a large soda would better serve those ends, whatever they are? And if you do happen to know such a person, do people like that comprise the majority of people you know?

Epilogue
I just realized how many logical fallacies are invoked in Conly's piece. Here's a list of all the ones I found, but do feel free to add to the list in the comments section:
  • Slippery slope fallacy (described above)
  • Appeal to authority (reference to Nobel Prize winning research on cognitive bias)
  • Bandwagon fallacy (appeal to the concerns of the majority, also described above)
  • Argument from fallacy (if the slippery-slope argument is wrong, then the argument against the soda ban is wrong)
  • Ecological fallacy (statistics on human cognitive bias do not indicate that individual soda-buyers are cognitively biased in the purchase of their soda)