Dave Barry was interviewed in this past Sunday’s New York Times Magazine. In the process, he described his pet peeve:
“One thing that is not in my fridge is ketchup and mustard. You know why? Because you don’t have to put them in the fridge! Too many Americans are putting cold ketchup on nice, hot hamburgers. And I ask those Americans, When you go to the diner, where is the ketchup? Sitting out on the table.”
Now, this made my wife and I laugh because it’s true: we have our condiments in the refrigerator and it never occurred to either of us not to. Yet, Barry is right. We never see ketchup anywhere but on the table at restaurants. We joked about it for a bit, clearly resolved to take them out of the fridge, and then Kim got the bright idea to look at the labels. Lo and behold, each has very explicit instructions to refrigerate after opening.
I would be hesitant to suggest that we were committing the appeal to authority. We weren’t persuaded by the fact that it was Dave Barry who told us to move our ketchup and mustard; we were persuaded by the evidence. His argument is irrefutable. Every day in restaurants millions of people eat ketchup and mustard from the table and they don’t get sick. How can that be wrong? One might argue that restaurant condiments get used much quicker than those at home, and that over the long term it's best to refrigerate them, but this doesn’t seem to be the case. The issue is, it seems like you don’t have to keep them cool at all.
So, there is a philosophical problem here. Not only who do we believe, but how to we evaluate the argument? First, we can’t believe Dave Barry just because he is Dave Barry; that would be appeal to authority. But, we can’t believe the ketchup and mustard people just because they are the ketchup and mustard people. That would be appeal to authority as well. But the ketchup and mustard people presumably have some expertise that makes them more reliable than Dave Barry, so maybe believing them is not the appeal to authority after all. Then again, the evidence that we have – years and years, case after case – verifies that Barry is right. Refrigeration is unnecessary. How do we determine who to believe?
There must be some standard of objectivity to evaluate the evidence, and presumably, that evidence has to be larger than our experience. Is it enough that millions of restaurants continue the practice, or do the tests have to be conducted in a laboratory? And if the latter is true, does this discredit the experience that we each rely on day-to-day?
Obviously, the most basic question is where we should keep our condiments, but the deeper one is how we evaluate the evidence of arguments. What counts as enough to regard a proposition as true? Dave Barry, you opened a Pandora’s box, and I’m not making this up.