Unbelievable

bathtubYou know that metal plate in your bathtub? The one with the little lever on it that opens and closes the drain? What happens when the water level rises above that plate?

When my sister asked me this question over Thanksgiving dinner, I answered, with the utmost confidence, that it causes (quite instantaneously) an enormous flood. (Note the exact wording. This will be important later.) My sister nodded sagely and said “That’s what I thought, too.” My sister and I had the same mother, you see.

And then she asked, quite innocently, “So. How exactly does that work?”. And I was stunned—absolutely stunned—to realize not only that I had no answer to this question, but that there could not plausibly be an answer. Which somehow had never occurred to me in the half century or so that I’d been harboring this ridiculous notion.

My sister had seen the light just a few weeks earlier when her husband was filling the bathtub. The water level had gotten perilously close to the metal plate, and my sister had frantically cried out that he was about to cause an “enormous flood”. (My mother’s contention that she never taught us any such thing is severely undermined by the fact that my sister and I shared not only the same bizarre misconception, but the same phrase to describe it). Her husband, puzzled, had responded appropriately with something like: “Huh?”. And she’d realized she had no answer.

Readers of The Big Questions will be aware that in my opinion, much religious belief is very like my belief in the mystical power of bathtub hardware. That is, it survives only because it is unexamined. It does not, in other words, run deep. And as a consequence, it doesn’t affect the way most people live their lives—because as soon as it starts interfering with your life (or with your husband’s bath) you set it aside.

Such “beliefs”, it seems to me, do not deserve to be called beliefs at all. In the words of Samuel Taylor Coleridge, “You do not believe; you only believe that you believe”.

I was recently pointed to a wonderful column by the philosopher Jamie Whyte, making the same point so vividly that I rushed to order two of his books from Amazon. As it turns out, they’re both the same book. Crimes Against Logic is the Americanized version of the original and very British Bad Thoughts. I randomly chose to read the British version, and it’s a blast. Whyte lists a dozen logical fallacies so blatant you’d think nobody could ever fall for them, and then gives you multiple examples of people who have fallen for them. Much snarky commentary ensues.

As Whyte documents, people speak a lot of nonsense. (I am one of those people. So are you.) You might be tempted to conclude that people are dumb, but I’m more inclined to conclude that people are busy. We’re all working so hard to be good carpenters, or good taxi drivers, or good teachers, or good parents, that we don’t have the time and energy to think hard about bathtub hardware or God or the consequences of a protective tariff. And most of the time, we don’t suffer for getting this stuff wrong. But every now and then it pays off—in some combination of enlightenment and entertainment—to pull out one of your cherished “beliefs” and ask: “So. How exactly does that work?”

Print Friendly, PDF & Email
Share

17 Responses to “Unbelievable”


  1. 1 1 sara

    Well, I can’t explain the plumbing behind this, but I can report that it’s true (at least in one house with old plumbing – houses with newer plumbing may have corrected the problem and be fine). :) My dad is terrible about watching out for this, and on a couple of occasions has done it and caused our second-floor bathtub to leak through the floor and ceiling and into our first-floor kitchen’s ceiling, to the tune of expensive repair bills! So I don’t suggest trying this unless you know your house does not have this problem. :)

  2. 2 2 Steve Reilly

    One interesting distinction between politics and religion on the one hand, and bathtub lore on the other, is that nobody gets angry about having their cherished bathtub beliefs questioned. If your view on “belieiving that we believe” is correct (and I tend to think that it is), it’s interesting that some of these believed-in beliefs are such an intrinsic part of our identities that we consider it rude to question them.

  3. 3 3 David Pinto

    Our tub had a screen, not a plate, so it was clear the water would drain if it reached the plate. All our sinks had those overflow drains as well.

    The one in our upstairs sink, however, was corroded shut. We found this out when my sister decided to wash rocks, and didn’t turn the faucet completely off. The water covered the bathroom floor and was discovered when it leaked into the living room below.

  4. 4 4 Rosa

    My “aHA!” moment about how we’re all dumb due to not re-examining things we think we know came in college, when one of my friends — an extremely smart young woman — explained to me that adding sugar, honey, or jam to plain yogurt leaches the nutrients out of it. When she told me this, I could only laugh, and after thinking about it, she realized it didn’t make sense.

    I could imagine a dozen ways this belief could have come about, and, once set, why it wouldn’t require reexamination, and I could immediately imagine that I must have dozens of similarly senseless “facts” in my thinking, too. Sadly, I am rarely able to discover them until someone is laughing at me or looking at me in confusion and saying, “What?”

    When I’m lucky, it’s someone I like, and then it’s a good story, at least!

  5. 5 5 Cos

    Could you explain your erroneous “believed-in belief”? I don’t get it about a sudden enormous flood when the water reaches a certain level. Did you imagine (before you thought about it) that somehow as soon as the water got that deep in the tub, magically it would expand to cover the rest of the room in an instant or something? That is, “how exactly does that work” seems a level too deep here, when I can’t even make sense of “what is it?”

    A more serious point: Many of us know many things that are quite true but that we don’t understand how they work.

    Some of them are so obvious we don’t think we need to understand them further (why don’t we fall through the floor into the basement? duh, it’s solid. so how exactly does “solid” work, differently from liquid or gas?)

    and some of them have been demonstrated true so we just accept them, and assume someone else understands them (planes fly, and people who don’t know how that works know that they fly; interestingly, it seems that until about two decades ago, nobody had the right explanation for exactly why shower curtains move inward when the shower is on)

    and some may not have been explained at all yet, but just happen to be true and match what people believe.

    What if you grew up in an isolated rural place where you’d heard of airplanes from several people, but never seen then and never had them explained to you, and just accepted that they were real, and then someone who hadn’t heard as much about them and was skeptical asked you “so how exactly does that work? how can something heavy enough to carry a lot of people, fly?”

  6. 6 6 Mark

    “we don’t have the time and energy to think hard about bathtub hardware or God or the consequences of a protective tariff”

    Many of them seem to have the time to go to church every Sunday or to protest about the ten commandments being removed from state buildings. Or even more destructively, they have time and energy to gather and protest NAFTA and to go to the voting booth every couple of years to vote for people who will impose tariffs and other undesirable policies.

    I’m more inclined to, as you say, conclude that people are dumb. At the very least they seem to be very poor at managing their time. As Larry Summers once put it, “THERE ARE IDIOTS. Look around”

  7. 7 7 ThomasL

    “[I]t seems that until about two decades ago, nobody had the right explanation for exactly why shower curtains move inward when the shower is on.”

    Why do they move inward? Some kind of Bernoulli/lift effect?

  8. 8 8 Snorri Godhi

    It is increasingly clear that this blog attracts a better sort of comments.

    I share Cos’ puzzlement as to why bath-tubs should have a metal plate specifically designed to trigger an enormous flood. I take Sara at her word that this does happen: I just don’t understand how and why. A metal plate with a lever is not something that I have seen very often. Most bathtubs that I have lounged in have/had a rubber plug, and an overflow drain as described by David Pinto. Perhaps it’s a European thing.

    I also like Cos’ Burkean attitude to irrational beliefs: just because we can’t explain why something happens, it doesn’t mean that it does not happen. The best examples are to be found in medicine and politics, rather than physics and engineering.

    As a medical example, there is a belief in my family that to take a bath less than 2 or 3 hours after a meal, especially at sea, is to face almost-certain death. It did not occur to me that the explanation I was given for this phenomenon (which fortunately I have never observed) is circular; until a friend of mine, medical student at the time, gave a plausible explanation.

    Political examples are more controversial, but let’s take the proposition that social democracy can only work in a small, homogeneous country. This proposition seems to fit the data fairly well, but why? I don’t know for sure, but I still think it would be foolish to ignore the historical evidence.

  9. 9 9 Revyloution

    I found your blog after hearing you on Talk of the Nation on NPR last week. It looks like a nice place to move in, and I look forward to reading your book.

    I know I had an unusual childhood (didn’t we all?), but I was inoculated against the idea of ‘beliefs’. My parents never talked to me about religions or gods, it was a non topic. It was similar for politics. Being raised like this taught me to hold on very lightly to anything that I hold as ‘truth’.

    The closest thing I ever had to a belief was the idea of Free Will. It feels like I make choices, so I just assumed that I had it. Someone challenged me that all life was deterministic, so I began reading a great deal on it. I finally agreed that all life is deterministic, and that free will is an illusion. (Comparing the Maugrim, and Stanford Prison experiments with the real world actions of Rwanda, Bosnia, and of course the Nazis started me down that road) I was very pleased to learn that I could easily change a firmly held belief so easily.

    As for the bathtub, I’ve installed a few tubs. Let me explain the mechanism.

    The metal plate that holds the plug handle is attached to a pipe that is connected to the P-trap below the tub. Pulling up on the handle closes a flap that connects the tub drain to the P-trap. When the drain is closed, the metal plate is still open to the P-trap. If the tub is filled to that plate, water will drain into it and down into the P-trap. Look at the bottom of the plate, you will see a gap where the water can flow in.

    For the plumbing uninitiated, a P-trap is a sideways ‘S’ shaped pipe that traps a small amount of water to prevent the smells from the sewer rising up into your home.

  10. 10 10 val

    In a lot of bathtubs the metal plate with lever also has a hole in it for overflow. Those without the lever will usually have a plate with a hole in it anyway, or some (like sinks) will have just a hole to extra drain.

    Since this hole seldom has water going through it (unless you’re like me, and try to get the bathtub as deep as it’ll accept) there’s the danger that said drain is corroded (as the person above mentioned) and also that it can’t handle the amount of water handed to it. Or worse, that the hole didn’t get properly connected to the plumbing on install.

    But it’s /supposed/ to be ThatAnnoyingExtraDrainThat’sFarTooFreakingShallow, which doesn’t exist in most of Europe/NZ/presumably elseworld ’cause they’re sensible and just put a drain on the bathroom floor, or doesn’t cause me problems when I want a ProperBath* because I’ve started using Glad PressNSeal to cover it.

    (This method is best used by people who fill the bath while in it, as otherwise you /will/ get an Enormous Flood when you get in and displace your bodyworth of water.)

    *in England the house had a bathtub I could’ve easily drowned in

  11. 11 11 Sierra Black

    I was just wondering yesterday why our new bathtub was so much more pleasant to bathe in than the one in our previous home. Answer: someone who lived here before me put duct-tape over the overflow drain in that big metal plate, and now I can fill the tub deep enough to actual cover my body with warm water!

    Prior to discovering this, I too believed that some sort of bathtime apocalypse would ensue should I overfill the tub.

  12. 12 12 val

    Sierra – as long as you don’t splash over the side you’re golden.

    If you’re in the US and lacking a drain in the bathroom floor, overspilling the side of the tub is indeed an apocalypse!

    (I use Press N Seal only b/c I keep forgetting to buy duct tape.)

  13. 13 13 Revyloution

    Stick with the Press N Seal. Duct tape will just get old, sticky and nasty looking. The Press N Seal is nice, clean and easily replaced.

  14. 14 14 Izzydog

    So is the point of this article that your belief in bathtub silver plates is equivalent to other’s belief in God, and if those incurious believers just looked hard enough they would immediately abandon their irrational belief in God just as you did with the silver bathtub plate? Okay, a colossal, arrogant, and fundamental misunderstanding of human nature, suffering the same problem that almost all comparisons to Nazis suffers – one of scale, but okay God and bathtub drain plates are equivalent matters. We’ll call it the JL theory.

    So at this point, according to JL theory, are we to assume that all true believing, church going, charity donating, praying, people who vote their irrational beliefs, write opinion pieces, talk endlessly on the radio, or whatever else they do in the name of their religion are acting irrationally when they engage in these behaviors? If so, why would you assume they suddenly become rational actors when it comes to the affairs of the marketplace? Especially when the two intersect so much?

    Or, according to JL theory, are we to assume true believers are really rational actors in everything they do despite their beliefs because all the hours and effort that church going, charity giving, praying, radio talking, legislation writing, intelligent design proselytizing, is really of no impact or consequence to their lives? But, according to JL theory, if they weren’t so busy trying to be what they estimate to be good based on their irrational beliefs, they would finally have enough time to examine the thing they think drives them to engage in these activities in the first place? And yet, because they are already rational actors in the marketplace, even if they examine their belief in God nothing would change at all. Heck of a theory.

    Or, is it just possible, that the belief in a marketplace with rational actors is just another bathtub drain plate. Some economists just believe that they believe. After all, belief in it is of no interference or consequence to anyone’s life…

  15. 15 15 Bennett Haselton

    Steve,

    I think there’s an inconsistency in how some of your writings treat people’s small-scale actions, and how they reflect our beliefs.

    You’ve said that when you say people don’t “really” believe the tenets of their religion, you mean that they would jettison those beliefs if anything huge (like their own life) hung in the balance. Small-scale actions, like putting a dollar anonymously into the collection plate, don’t count.

    On the other hand, you’ve said that if someone pays a dollar to avoid a one-in-a-million chance of death, that indicates that they value their life at about a million dollars.

    So, which is it? Do small-scale actions betray our “true” beliefs, or don’t they? If someone anonymously donates a dollar to the church, why doesn’t that reflect their “true” beliefs just as much as paying a dollar to avoid a one-in-a-million chance of death? Is there some way to reconcile these that I’m not seeing?

  16. 16 16 RL

    “people speak a lot of nonsense. (I am one of those people. So are you.) You might be tempted to conclude that people are dumb, but I’m more inclined to conclude that people are busy.”

    And yet the “dumb” hypothesis explains so much…

    Note, for example, that it explains the fact that so many people are not strikingly competent even in the things they are busy in…

  17. 17 17 Cos

    lazydog: I highly doubt this post is specifically about religion, and I don’t even think it’s intended to really apply to religion. Religion, for a lot of people, is about beliefs they *do* examine, but have specifically decided not to demand a “how exactly does that work” explanation for. This post is about things people believe without having thought about, and which they would not hold if they discovered there were no such explanation for.

    ThomasL: Turns out the reason is a vortex of circulating air induced by the shower water. People always explained it in terms of different air pressure on either side, but the way that happened was misunderstood.
    http://www.scientificamerican.com/article.cfm?id=why-does-the-shower-curta

  1. 1 Weekend Roundup at Steven Landsburg | The Big Questions: Tackling the Problems of Philosophy with Ideas from Mathematics, Economics, and Physics

Leave a Reply