Wednesday, May 04, 2005

Modal Cognition

Suppose my modal formalism is true. There is no one privileged or 'absolute' standard of possibility for people to make modal judgments against. Instead, our concept of modality should be 'relative', in that there are different modal frameworks we can work within (e.g. physical vs. logical possibility) and that yield different results. We should have no universally-applicable 'default' framework. If asked to make modal judgments (without instruction to use any particular framework), what framework we choose to work within will depend on the context.

That's my claim. I've no idea whether it's true or not. But I'm thinking of doing my cognitive psychology project on it, to find out. My rough plan is to present participants with one of three stories, to prime their thinking towards a particular framework, followed by a series of (officially unrelated) questions about what is or isn't possible. I'm thinking of presenting participants with something like the following (but this isn't finalized yet, so any advice would be very much appreciated!):

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[Experiment]
We all recognize that the world could have been different. For example, it happens that the Americans were first to the moon, but it could have been the Russians instead. Please read the following short passage, and then answer the questions that follow. There are no tricks -- please take all the questions at face value.

[One of the following three passages now follows:

(i) Bobby wondered whether history could have unfolded differently. Maybe New Zealand would have won the last cricket World Cup, or maybe the Roman empire need never have collapsed. Bobby liked to think about different ways the world might have been.

(ii) Bobby wondered whether the laws of physics could have been different. Maybe there would be no gravity, or no friction. Bobby liked to think about different ways the world might have been.

(iii) Bobby wondered whether the laws of logic could have been different. Maybe there would be true contradictions, or other things we find incomprehensible. Bobby liked to think about different ways the world might have been.]

What do you think? Please answer 'yes' or 'no' to the following questions.

Might it have turned out that...
1) Germany won World War II?
2) humans coexisted with dinosaurs?
3) cows could jump over the moon?
4) cheetahs could run faster than light?
5) 2 + 2 = 5 ?
6) a ball could be red all over and blue all over, at the same time?

[End experiment]
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It sounds a bit crazy, I know, but that's philosophy for you. Are the instructions at least reasonably clear? Could the priming passages be improved somehow? Or perhaps the questions themselves? Any other suggestions?

11 comments:

  1. Richard,

    I agree--and I think most other philosophers should as well--that there are different types of alethic modality, each relevant in different contexts.

    I also think that the experiment you're putting together is interesting. However, I worry that the students might not understand the implications of your questions. The first pair violate contingent truths of our world of the past, the second pair violate truths of physics, and the final pair both violate the laws of logic. (Actually, I'm not sure where to put the question about the cow. Would a cow jumping over the moon be a violation of the laws of physics? What if it was a really, really, really strong cow?) However, it might be a bit presumptuous to assume that your subjects will know that a cheetah running faster than the speed of light is impossible, or that something being both red all over and blue all over at the same time violates the laws of logic. (What about cars with iridescent paint jobs? They are, in some relevant sense, two different colors all over at the same time.)

    I guess another worry is that, perhaps philosophers shouldn't worry about what lay-people say about modality, since we can ourselves stipulate the modal contexts while doing our work.

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  2. Chris-- Which law of logic would be violated by a thing's being red all over and blue all over?

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  3. Chris, you're right that I need to be careful to make the questions as clear as possible. Can you think of any suggestions to improve them? (You've correctly noticed the pairings I had in mind -- can think of any clearer or more representative question that could serve my purposes for them?)

    Perhaps "purely red" (etc.) would be better than "red all over", at making the contradiction clearer in Q6.

    (And don't most university students know about the speed of light?)

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  4. David,

    It doesn't violate a law of logic per se, it's just a typical example of a contradiction used by philosophers. Supposedly it is something we 'cannot conceive.' I actually think that red and blue are a poor choice of colors anyhow. You'd probably want opponent colors, like red and green. In any case, I don't think it violates the laws of logic (hence my iridescent example), but it has been an example I have heard philosophers use along with round squares and such.

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  5. Richard,

    I'd like to think that all university students know about the speed of light. Maybe kids are more intelligent in New Zealand. I suggest using the 'round square' example rather than red all over/blue all over. I might change the one about the cow too, but I think it will probably work fine.

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  6. The traditional reason the "red all over, blue all over" case would be regarded as a violation of the laws of logic is that it is a case in which contraries are treated as both true; logically speaking, contraries can both be false, but they can't both be true. (The 'all over' part is supposed to indicate that we can't save the conjunction by reduplication or technical distinction, as in the iridescent case. In other words: it's simply red, end of story, and it's simply blue, end of story.)

    The point about exclusion of contraries brings up an interesting issue, since I rather suspect most undergraduates would miss the point (I agree that the color example is not very clear, since it involves granting several implicit stipulations; but even a better example might be tricky for undergraduates.)

    I wonder if the "or other things we find incomprehensible" might be a bit misleading in the third case.

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  7. Hmm Im not sure I fully understand this - I would say anything is possible depending on how many assumptions you are willing to bend/break.

    I would in the first instance say "no it is not possible because it didn't happen"
    but it is theoretically possible that "light particles" might be bigger and not go so fast. All I can do here is oprder them in the degree of change required to make them true (without cheating by changing definitions of words)

    1) Germany won World War II?
    2) humans coexisted with dinosaurs?
    3) cows could jump over the moon?
    4) cheetahs could run faster than light?
    5) 2 + 2 = 5 ?

    if any later number changed the earlier numbers would be fundimentally changed for example any world where cows jump over the moon (4) is unlikely to have humans as we know them now.(3) and without that you hardly can have a WWII as we know it. (I exclude the ball one because it seems possible to me - in fact some might point to a purple ball)

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  8. Yeah, "round square" would be better than Q6, actually. And I might change Q5 too, if I can think of a better logical impossibility. Maybe a proof of the theorem which states "this theorem cannot be proved". Or a barber who shaves all and only those who do not shave themselves.

    Genius - "I would say anything is possible depending on how many assumptions you are willing to bend/break."

    Yup, I agree. The point of my experiment is to see whether people's judgments of what's "possible" will be influenced by a priming passage. For example, those who get the 2nd passage should be more likely to say it's possible to break the laws of physics (e.g. by having a cheetah run faster than light).

    (Though I'm not sure whether anyone will be willing to break the laws of logic, even if primed with passage iii [which I've changed slightly from that described in the post]. That will be interesting to see.)

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  9. Oh, I know, I'll ask if there could be a man who speaks truly when he says "everything I say is false".

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  10. I'm not sure that this produces a standardized effect against which the attitudes towards the questions can be measured.
    The last one of course is relitively difficult to comprehend but you could easily be testing the definition of concepts like "true" - ie in a universe where true and false coexist is "true" actually still "true" as we define it?

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  11. Actually I love your example of "red all over, ..." unashamedly because I used it to illustrate an example to a friend, and I'd like to think of fine minds thinking alike. Doesn't it come from A.J. Ayer's "Language, Truth, and Logic," where he illustrates analytical statements this way?

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