Tag Archives: burden of proof

The Conjunction Fallacy and the Burden of Proof

11 Thursday Jan 2018

Posted by in atheism, Athesism Christianity, christianity, logic, philosophy, rationality, religion, Uncategorized

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As you know I think the philosophical burden of proof is a notion harmful to clear thinking.  My first post about it was here.  And here is a blog from someone who thinks very much the same way.  Here I will try to score some further points by undercutting common arguments used to support the view that having a burden of proof is helpful.

But first some background, what is the conjunction fallacy? Consider this example from Amos Tversky and Daniel Kahneman copied from Wikipedia:
“Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.

Which is more probable?

1) Linda is a bank teller.
2) Linda is a bank teller and is active in the feminist movement.”

If you thought 2 was more probable, then you committed this fallacy.  It is a formal fallacy.  And it basically says that the probability of A+B will always lower or equal than the probability of A. As we add conditions the probability can only go down never up.

Why is this tricky to some people? (apparently most people chose option 2) Given the description of Linda many people might think she sounds like a feminist. Moreover, she does not sound like a bank teller. So the first option seems to only have what people think is unlikely.  Even though second option has what seems unlikely it also has what seem likely too. So the second option may seem preferable. But mathematically the second option will never be more likely than the first, because every time the second option holds true the first does as well.

When we add details to a claim the probability tends to drop. The probability that I am in front of my computer now, is greater than the probability that I am now in front of my computer wearing a shirt, which is greater then the probability that I am now in front of my computer wearing a brown shirt. This is just how logic works.  I think many of us know this and build this into our understanding of the world. So what does this have to do with the burden of proof?

If you go to youtube and type in burden of proof the first video to come up will be this one:

Listen to the first 20 seconds.
What is happening?  Well if you notice the person is not just asking whether “something” exists “in space” that we don’t have evidence of and whether we should believe that. Which I tend to think is true – that is I do think there is something in space that we do not currently have evidence of.  So how would that help his case for “the burden of proof”? Of course it wouldn’t.

So he doesn’t just ask whether a general thing exists.   Instead he gets absurdly detailed with his description.  It is not something we don’t know about somewhere in space but under the surface of Pluto! And it is not just “something” its not even just some form of life, but a walrus. And of course even that is not enough. It is a “tiny” “were” walrus. But not only that it is a “psychic” tiny “wer”walrus. But no tonly that!  It is a tiny psychic werewalrus that “sends them psychic messages.” But not only that, the messages come “every midnight.” And not only that but it does this while juggling skulls…..

Ok. So by now if you understand the conjunction fallacy  then you will know that amount of detail alone will drastically drive down the probability. There is no need to appeal any “burden of proof” to not believe in this creature. The probability is naturally driven down just by understanding the conjunction fallacy.

It’s amazing that this video received 13,000 likes when it is really just an obvious play on this formal fallacy. Now if you are like me you will see this quite often from atheists. The other day when I said there is no philosophical burden of proof I was asked whether I believe “that there is an imperceptible penguin named “Percival” standing right across the room from me, wearing his imperceptible tuxedo and his imperceptible monocle and his imperceptible derby hat, holding his imperceptible pocket-watch.”

Now I want to point out that the proponents of a burden of proof who use these examples are not themselves committing the conjunction fallacy. But rather they just seem oblivious to its logic. It is the logic that makes the conjunction fallacy a formal fallacy that makes the probability of their examples quite low. So when you see these examples the response is not that they are committing a fallacy. Rather the response is more like yes the conjunction fallacy is indeed a fallacy so the probability of your extremely detailed scenario is low.

If you express doubts about “the philosophical burden of proof” you can expect this sort of thing. They won’t ask whether you can believe there is something somewhere we do not have evidence for. No, they will not even ask whether there is some species of life we have no evidence of yet. Rather they will ask about a particular horse that we have no evidence of. But not just a horse, but a horned horse, but not just a horned horse, but a horned horse with exactly one straight long horn coming out of its head. And often even that won’t be enough the horned horse will have to be pink.

And you might respond explaining this fallacy and ask them whether they believe there is something somewhere he/she does not yet have evidence of. I certainly believe there are things that exist that I have no evidence of. For example there very well may be a particular cricket in the southwest United States that I have no evidence of.

Which brings me to another point here. There is more than just the conjunction fallacy at work here. There are also background beliefs. There are probably crickets in the southwest United States. But when and how did a walrus get to Pluto? (forget the whole juggling psychic were bit)

Perhaps the classic example of this sort of argument is Russel’s Teapot. Russel said:
“ … nobody can prove that there is not between the Earth and Mars a china teapot revolving in an elliptical orbit, but nobody thinks this sufficiently likely to be taken into account in practice. I think the Christian God just as unlikely.”

So again, its not just something in space we don’t have evidence of.  It is something between the Earth and Mars and revolving in an elliptical orbit. It is not just something but a piece of China. And it is not just China but a China teapot. So we can see the logic of  conjunction fallacy at work reducing the probability.

But we also have background beliefs and evidence at work as well. Plantinga wrote:
“Clearly we have a great deal of evidence against teapotism. For example, as far as we know, the only way a teapot could have gotten into orbit around the sun would be if some country with sufficiently developed space-shot capabilities had shot this pot into orbit. No country with such capabilities is sufficiently frivolous to waste its resources by trying to send a teapot into orbit. Furthermore, if some country had done so, it would have been all over the news; we would certainly have heard about it. But we haven’t. And so on. There is plenty of evidence against teapotism.”

Another example might be if I say if we randomly pick a house in a New York suburb will there be three black horses in the Garage? You might say no. One reason would be conjunction fallacy. But also you would have back ground beliefs about what suburban houses likely have in their garage. If I asked does that house have light fixtures in it, well then you might say yes.

So Plantinga brings up evidence. And I think that may be a good way to describe what he is doing. But sometimes there are things that just don’t accord with our background beliefs. Now maybe these background beliefs are rational maybe they are not. Sometimes it may be difficult to completely understand or articulate why a certain claim seems true or untrue. Is there something beyond the known universe? In any case we have far more beliefs than we may even consciously realize.

For example, I never realized I believe plaid cats do not exist until last month. But I suppose I always believed it. (that is I was inclined to act in a way that accorded with the statement “there are no plaid cats”) This may be a sad fact of this kluge we call our brains. But it does not justify erecting some imagined burden of proof.  That is just piling error on top of error. When we consider 1) our background beliefs, 2) evidence and 3) the logic of the conjunction fallacy there is no reason to appeal to the burden of proof.

If you are so inclined I would love it if people would post a link to this blog in the comments of the above youtube video. Perhaps we can get a discussion going and deepen everyone’s understanding of this issue.

“The Burden of Proof” versus “The Flying Spaghetti Monster”

26 Sunday Jan 2014

Posted by in Uncategorized

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In the law legislatures create burdens of proof so that fact finders can be guided on how to decide a case in light of uncertainty.    The same is done for debates where a “winner” and a “loser” needs to be decided.    These burdens exist so far as we make them up.  But what I would like to talk about is the notion of a “philosophical burden of proof.”

I would suggest that such a thing does not exist and the sooner you free your mind of the notion the better off you will be.

First, let’s address what people mean when they say “you have the burden of proof.”   I think there are actually quite a few questions along these lines but let’s just try to give a statement of what they might claim it is.  Tonight’s version of Wikipedia says this:

1)      “When debating any issue, there is an implicit burden of proof on the person asserting a claim.”

I think that sounds pretty much what I hear.  I might also hear something like this:

2)      “The person asserting an affirmative claim has the burden of providing evidence for his claim”

I don’t really think there is much difference between the two.

Now the first thing I would note is that both 1 and 2 are themselves claims which are often affirmatively asserted.   Yet I do not ever hear any proof or evidence that they are true claims.   Is this yet another case of a self-defeating claim?   It seems so.

But before we leave tonight’s Wikipedia I would note that it also says: “The fallacy of an argument from ignorance occurs if, when a claim is challenged, the burden of proof is shifted to be on the challenger.”  That’s true but misleading.  The Fallacy of ignorance occurs when someone argues that because you failed to provide enough evidence to convince them X is true that lack of evidence should somehow prove “Not X.”   So it should be clear that this fallacy in no way justifies a burden of proof.    If anything the fallacy of ignorance is a case where people draw faulty conclusions based on the assumption that a burden of proof exists.      If one never believed in any burdens of proof then it would be much easier to avoid the fallacy from ignorance.   Although I concede that someone can believe in some form of “the burden of proof” and not commit the fallacy of “argument from ignorance”, they are close relatives.

For example we can see this fallacy when we read what atheist Kieth Parsons says about Hanson another atheist writer  “According to Hanson, the same holds for the claim that God exists. To show that no compelling evidence or cogent argument can be offered in support of God’s existence is tantamount to showing that God does not exist.” Page 25 in his book “God and the Burden of Proof.”  This is about as clear a case of the fallacy of argument from ignorance as I have ever seen in a philosophy text.  And the fallacy is committed because of the author’s commitment to this imagined burden of proof.

Now, if Bigfoot or fairies existed I would expect we would have better evidence of them.   They are presumably material things that can be seen, captured, photographed, video recorded etc.    It is in part because I would expect that we would have better evidence than we do, that I do not believe they exist.   Moreover the existence of fairies or bigfoot has no other impact on my other beliefs such that I should weigh in favor of believing they exist.  Notice though I am stating my reasons why I do not think fairies or Bigfoot exists.   And indeed that is why I don’t think they exist.    I feel no need to resort to claims someone else needs to shoulder some imaginary burden of proof.  If someone believes in Big foot and I give him my reasons and he still believes ok.   I do not insist that he needs shoulder some burden to prove it to me.  He does not have any such burden.

Ok I imagine there are some readers who will want to ask me questions like “Do I believe that there are purple and yellow spotted platypuses on planets other than earth? And if not why not?”   Well the answer is no, and the reason I don’t is because it sounds made up.    Someone asked me “But what if someone who really believes it tells you this?”  I’m sorry but it still sounds made up.  Perhaps I just grew up with too many people who thought it was entertaining to fool people and so I am a bit distrustful.   When my brother first told me about quarks I thought he was making that up too.      But either way the person who believed in these platypuses would not have any burden to prove this to me.

Do I think we should have reasons for all our beliefs?  Maybe.    But I think 2 points are important here:

1) This is different than saying some “burden of proof” exists.  I might hold the belief that we should have a reason for our beliefs without alleging any sort of burden exists on others to prove anything.

2) The problem with the idea that we should always have a reason for our beliefs, is that the chain of beliefs needs to start somewhere.  If we have to have a reason for all our beliefs we would either be guilty of circular reasoning, or capable of holding an infinite set of beliefs, or believing things for reasons that we do not really believe,  or in a situation where we shouldn’t believe anything at all.   There is the logical possibility that all our beliefs stem from other self-evident truths.  But I don’t believe that is the case.

So right now although I might be sympathetic to the idea that we should have reasons for our beliefs.   It seems there are problems with even that claim.

If you are still convinced that “the burden of proof” is real, I have a few other questions:  1) What is the standard of proof? (e.g.,beyond reasonable doubt, or preponderance of the evidence or fair probability or clear and convincing evidence? Ect.)  2) To whom do I need to prove the claim? (e.g., a judge, a commission,  a jury?)   3) What are the supposed consequences of not meeting this burden?  (go to jail or not, win a money judgment, get an injunction move on to the next round of debate in the winners bracket?) These are all very clear in Courts and debates.     How does this supposed philosophical burden of proof work?

In the end however I believe the notion that others have some burden to demonstrate truths to you does indeed suggest that you are not required to figure it out for yourself.   Believing that you are somehow epistemologically justified in continuing to hold your beliefs so long as you decide some other person did not meet some imagined burden of proof is a poor way to go through life.   If two people give their reasons for believing opposing views and neither convinces the other, so be it.  Maybe one is stubborn or irrational who knows.  (see my blog giving a proof of God)  Thinking that we should insert some burden of proof never helps any discussion.    I think it is intellectually more healthy to place the burden on ourselves to investigate any sort of important question.  Don’t try to pass that off on others.

So anyway who wins “The Burden of Proof” or “The Flying Spaghetti Monster”?  In the end I think the evidence weighs in favor of “The Flying Spaghetti Monster” after all, at least we have pictures of it:

Image