POLL 4 on a very simple argument especially designed for Sarkus

Discussion in 'General Philosophy' started by Speakpigeon, Jan 26, 2019.

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Is the argument valid?

Poll closed Feb 25, 2019.
  1. No

    16.7%
  2. Yes

    50.0%
  3. I don't know

    0 vote(s)
    0.0%
  4. The argument doesn't make sense

    33.3%
  1. Quantum Quack Life's a tease... Valued Senior Member

    Messages:
    23,328
    x (may be) (some part) of B;
    y is some part of B;
    Therefore, x may be y.


    There are two modal operators ... yes?
     
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  3. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    SP can speak for himself. As for me, sometimes you can't tell and I've got more pressing matters.
     
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  5. iceaura Valued Senior Member

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    30,994
    That's not redacted.
    It is not expressed clearly as a syllogism - further restriction on the terms is necessary. And your terms "some part" and "may be" are not clear in this context - no dictionary will help.
    Sorry to hear that. Perhaps a thesaurus?
    And whenever that is - existentially - the case, you have true premises and a false conclusion.
    It means one or more of the following: "x may be B1 but not B2"; "x may be B2 but not B1"; "x may be either B1 or B2 but not both"; "x may be B1, B2, or both". These are not logically equivalent, and each one would produce a different syllogism if rigorously cast.
     
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  7. LaurieAG Registered Senior Member

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    577
  8. Speakpigeon Valued Senior Member

    Messages:
    1,123
    Yes, "possibly could". To say that x and y may be different, or "possibly could" be different, doesn't imply that it is not true that x and y may be the same.
    You have to assess validity on form only. So, you have to assume you don't know that x and y are different since, on form, the premises don't imply that they are different.
    Assuming as you do that x and y are different is logically equivalent to adding an implicit premise in the argument saying "x and y are different", and then it's a different argument, and one which is indeed not valid.
    Yes, but you can't assess validity by assuming you know that x and y are different when the premises don't imply, on form only, that x and y are different.
    But you can't assume that x and y are different.
    OK, I get your point, but your example works against your suggestion. The engine is some part of the car, not any part of the car.
    And you still need to explain the difference between "x is some part of B" and "x is any part of B" in the context where we don't know x and B.
    In effect, you add a semantic difference if you give an interpretation to x and B, say, "engine" and "car". It is logically equivalent to adding two extra premises, "x is an engine", and "B is a car".
    Then, yes, there is a difference between:
    -- "x is an engine and x is some part of a car"
    -- "x is an engine and x is any part of a car"
    But if you don't specify what x, y and B are, as in the argument, then, for all you know, "x may be some part B" is logically equivalent to "x may be any part of B".
    And then, semantically, keeping soundness in mind, you have to choose between "any" and "some". To say for example that the person's conscious mind may be the state of any group of neurons in the person's brain is probably not something we want to say is true. This is because, as your engine/car example shows, "any" subjects the proposition to more conditions to be true.

    Still, I don't want to obfuscate, but if you have a point, you still need to articulate it.
    EB
     
    Last edited: Jan 28, 2019
  9. Speakpigeon Valued Senior Member

    Messages:
    1,123
    No. It means, and imply, all of them at the same time.
    "x may be B1 or B2" implies "x may be B1 but not B2";
    "x may be B1 or B2" implies "x may be B2 but not B1";
    "x may be B1 or B2" implies "x may be either B1 or B2 but not both";
    "x may be B1 or B2" implies "x may be B1, B2, or both".
    It would indeed be a different argument.
    Start a more rigorous thread on it if you're more rigorously interested.
    EB
     
  10. Speakpigeon Valued Senior Member

    Messages:
    1,123
    ???
    Can't you articulate your point?!

    Still, as your link explains, the modal fallacy is the fallacy in modal logic of inferring that because something is true, it is necessarily true.
    Sorry, but I fail to see the relevance of that to my argument.
    So, can you articulate your point?
    For now, it seems you don't have any.
    EB
     
  11. Baldeee Valued Senior Member

    Messages:
    2,224
    For the form to be valid it must be impossible for the premises to be true and yet the conclusion false.
    Where x and y are different the conclusion, that x and y may be the same, is false.
    Thus the form seems invalid.
    You don't have to assume that you don't know they are different at all.
    The form has to hold for all specific examples of x and y.
    The form of your argument patently doesn't.
    If you want to introduce the qualifier that it is not known whether x and y are different or not, that would need to be a premise.
    Otherwise, on form, your argument seems invalid, because one can example specific X and y that make the conclusion false.
    If you don't make an explicit premise as to what is known, one neither assumes that is known or unknown, only that you have x and y (and B) to which you can apply specific examples.
    If you don't want x and y to be known then add that into your premises.
    I don't assume that I know that they are different.
    They just are different in the example I used.
    Your argument fails to address such a case, resulting in a false conclusion from true premises, and is thus seemingly invalid.
    Im not assuming.
    However, in the example they are.
    You asked for how the two were different.
    Of course it works against my previous example, because my previous example was a demonstration of the invalidity of your argument.
    However, applying the seat/engine/car example to this new wording (using "any") then if we accept the premise as true that the engine is any part of my car (i.e. we are defining any and every part of my car as "the engine") then the seat may be the engine.
    I.e. The seat may be a part of my cart.
    Why?
    I don't need to assume that x and y are not different.
    There is nothing in the premises that suggests either way, so the test of validity can use any x, y and B.
    Your argument seems to fail such a test.
    If you want to limit the argument to unknowns then you need to specify that within the premises.
    No more so than introducing the name Socrates, the notion of man, and being mortal.

    Take the classic non-modal syllogism:
    If P then Q
    P
    Therefore Q.
    It doesn't matter what P and Q are, the argument is valid because it is impossible for the premises to be true and yet the conclusion false.
    If you start saying "ah, but we don't know what P and Q are, and if we did then for some P and Q it may be shown to be invalid, but doing so introduces additional premises that P is such and such, and Q is such and such" then you would have a case for showing that the syllogism is invalid.
    But this form is valid precisely because it is impossible for the premises to be true and the conclusion false irrespective of what P and Q are.
    Your argument, as worded in the OP, seems to fail this test of validity.
    I, and iceaura, have come up with examples where the premises are true and the conclusion false.
    We are making no additional premises, we are simply applying examples to x, y, and B.
    If you think that this is adding an assumption that we know x and y to be different then you need to add a premise to specifically exclude this possibility... e.g. a knowledge qualifier of some description.
    Sure, if you don't specify what x, y, and B are then you are introducing a knowledge qualifier of "unknown".
    But your argument as worded doesn't have this qualifier.
    One can then apply any specifics to x, y, and B, and as a result show your argument to be invalid, as worded.
    If you change a word and thus the meaning, you can change an argument from being valid to invalid.
    An invalid argument can never be sound.
    Not a concern for this thread.
    You asked whether the argument in the OP is valid or not.
    I don't think it is, and I think I have justified why I don't think it is.
    I have offered you a solution or two as to how it might be made valid, the change of the word to "any" getting you past the rather obvious undistributed middle that you seem to have a specific grievance against.
    The reasons for considering your argument invalid have been articulated adequately for purposes: it is possible for your argument, as worded, to have true premises and yet a false conclusion, as demonstrated.
    Your counters to that (e.g. knowledge of whether x and y are different etc) have been considered and duly shown to be unfounded, as explained above.
     
    Sarkus likes this.
  12. Quantum Quack Life's a tease... Valued Senior Member

    Messages:
    23,328
    x may be some part of (x)B(y)
    y may be some part of (x)B(y)
    However x =/= y as x and y are some part of B
     
  13. iceaura Valued Senior Member

    Messages:
    30,994
    They are mutually contradictory. So you have either four different syllogisms, or one from a selection of ten or eleven immediately invalid (combination) syllogisms, or a rewritten one without the muddle.
    Let's say you choose one of the self-coherent premises, or rewrite the whole thing for clarity:

    At that point the link in post #24 does you the favor of labeling the flaw in your conclusion, and instructing you in its resolution.
    So how would you suggest we proceed? You have had the basic problems with whatever your argument turns out to be described in some detail with examples, and named, and linked.
     
  14. Yazata Valued Senior Member

    Messages:
    5,902
    You seem to have appointed yourself the board's logic professor. If you want to play that role, then you need to demonstrate that you actually have superior knowledge of the subject.

    Instead of just endlessly posting your little quizzes, in hopes that maybe someday somebody might agree with you, tell us what you believe the correct answer to each one is.

    Most importantly, explain why you think that your own answer is the correct one. Actually teach us something.

    In real life classrooms, the quizzes come after teaching has occurred.

    I don't feel like playing that game any longer.

    If you have something that you want to say about modal logic, then say it.

    (It seems to me that set theory might be more relevant, since in "x may be some part of B", B appears to be a set.)
     
    Last edited: Jan 28, 2019
    Sarkus likes this.
  15. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    Messages:
    10,300
    While i am indubitably honoured for you to have created a thread specifically for me, speakpigeon, with my name in the thread title, I must concur with Yazata above: enough of the pandering. Your arrogant manner is not backed by anything that comes even close to warranting it, and your dismissal of views that run counter to your own are laughable for their lack of understanding.
    You clearly think the argument is valid. So show us that it is. Show us that it is impossible for the premises to be true yet the conclusion false, that being the usual definition of validity. Iceaura and Baldeee have provided examples of where the premises can be accepted and the conclusion nonetheless false. So the ball is in your court.
    Or do you require their points articulated (one of your many go-to responses when you seem to have nowhere else to go) despite the points already being articulated far more clearly than should be needed. Or is it that you think they are redacting your argument simply by providing a specific example of the form (another of your go-to responses when you don't like the result) that shows the argument to be invalid?
     
  16. Quantum Quack Life's a tease... Valued Senior Member

    Messages:
    23,328
    I do realize I am out of my depth in this somewhat but I have an issue with the key word "may".

    The best way to exemplify it is to use the liars paradox again.
    compare self referencing statements:
    This statement is false
    with
    This statement may be false

    Now as far as I can tell the word "may" automatically infers "may not"

    so when we read the test statement from SP
    we can read:
    x may not be part of B
    y may not be part of B
    x may not be part of y

    The key thing is that the words "may not" do not infer any possibility of the contrary where as the word "may" does.

    any thoughts welcome...
     
  17. Speakpigeon Valued Senior Member

    Messages:
    1,123
    I have not appointed myself.
    I started a thread on a logical argument and we're having a discussion on the topic.
    You should know that philosophy can be taught asking apparently innocent questions. I certainly hope you're all learning something here. I certainly do.
    You can use the formalism of set theory but I would hope you're not that desperate. Why not use the atomic bomb to make the problem disappear?
    EB
     
  18. Speakpigeon Valued Senior Member

    Messages:
    1,123
    The word "may" here should be understood, as in ordinary English, to signal possibility: It is possible that p if we don't know that not p.
    But "It may not be that p" just means that it is not possible that p. Or, it is not true that we don't know that not p, which implies that we know that not p.
    This is different from "It may be that not p", which just means we don't know that p. If we don't know that it rains, then may be it doesn't rain.
    EB
     
  19. Speakpigeon Valued Senior Member

    Messages:
    1,123
    That's definitely a matter of personal appreciation. As I see it, you're the rude and arrogant one. You've been repeatedly abusive in your language and this without any prompting on my part.
    Yes. And it certainly seems common sense to me.
    I have to say, I'm amazed that you should be so many to deny validity here. Especially coming from Baldeee, who seems the more knowledgeable of the lot.
    I've already explained all that you need to know. See my reply to Baldeee. There would be no use repeating myself.
    I already explained why it's no good.
    I understand what they have articulated and this is mistaken. Other people fall into the same trap and seem similarly unable to get out of it.
    I do observe again that it seems to be the very people who are the more likely to have had some training on formal logic who get it wrong, and for the same reason.
    Still, it's not the end of the world. I'm not concerned with your intellectual capabilities. I'm sure you're fine. This shit seems to have more to do with Pavlov. But it's up to you to retrain yourself. Read Aristotle as an antidote.
    EB
     
  20. Speakpigeon Valued Senior Member

    Messages:
    1,123
    See my reply to Baldeee.
    EB
     
  21. iceaura Valued Senior Member

    Messages:
    30,994
    But if we do know that not p, it is not possible that p.
    And until you clarify your muddled (and apparently, by your own description, self-contradictory) statement of it, your premise allows that situation. That renders the conclusion not necessarily true, not necessarily following from the premises. That renders the argument invalid.
    See the link to the "modal fallacy", helpfully posted for your edification in #24.
    Yes, you can. That is one of the situations you explicitly agreed (post 26) was allowed by your premises.
     
  22. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    Messages:
    10,300

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    Where do you honestly think I've been abusive? And repeatedly so?? By saying that you are acting like a troll? Or are you a snowflake such that you think disagreeing with you is somehow being abusive?
    Many things are accepted on common sense when they're incorrect. And, if incorrect, your acceptance of the validity of the form wouldn't be the first, nor the last.
    Well, feel free to show us all the proof that it's valid, then. Or is your "common sense" the only thing you've got going for it? Seriously, post the proof that it's valid.
    You mean the reply to Baldeee that he subsequently tore to pieces in #28?
    And those explanations have, to quote Baldeee's latest post: "been considered and duly shown to be unfounded, as explained above". Do you have anything else to offer?
    First, if you consider their points to have been articulated, try not to be dishonest and handwave them away by asking them to articulate their points (see your last line in post #25). Second, you think they are mistaken, yet you haven't provided any proof, only provided rebuttals that seem to have been shown to be without substance.
    So now you think there's a trap? What trap is that? What is it that you think these people are unable to get out of? At the moment we have your confidence that the argument is valid but seemingly based on nothing of actual substance. So what trap is it that these people are in, exactly? Or are you just looking at people who hold a different view and trying to convince yourself that your position is safe, there's a trap? Because you're not doing a great job of convincing anyone else.
    And yet you, who clearly hold yourself above those you think the more likely to have had some training, are unable to prove to them that they are wrong? Not even that, you can't provide adequate reasoning for why they are wrong, let alone a formal proof.
    Could these people be wrong? Yeah, sure. Of course. But so far they're the only ones with justifications still standing.
    I'm not asking you to be concerned with my intellectual capabilities. But you should be concerned if you have nothing of substance with which to rebut those who disagree with your position, especially when you clearly think yourself above everyone else here on this matter.
    Yeah, someone comes along with an attitude and posts shit, and I duly respond to that bell. Like Pavlov's dog to a mixed metaphor flame. That's definitely my weakness. I'm fodder for trolls. But I'm learning. I take one day at a time. But thanks for your concern.
    To your trolling? Yep, he probably is.
     
  23. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    I can't understand why people here are trying to shoehorn a logic with 3 defined values into a logic with 2.

    Yes, the argument as presented has 3 logical values: true, false, and indeterminate (but one of true or false).
    The truth tables for arguments in 3-valued logic are a bit larger than for ordinary old 2-valued logic, but they exist.

    What the hell is going on here? I demand to know and will not be deterred until I do . . .
    (yes you're allowed to take that seriously)
     

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