Comments

  • A Case for Moral Anti-realism
    I did indeed promise to answer your question, but I am under no obligation to do so".

    You don't see this as problematic?
    Banno

    No, because it isn't clear to me what obligations are, or whether or not they exist, and you are yet to make sense of them.

    Then I need provide no answer.Banno

    So you will neither make sense of nor defend your claims? OK.
  • A Case for Moral Anti-realism
    So this tells me only that you will not be held to your promises.Banno

    I don't know what it means to be held to a promise. You don't seem to want to make sense of obligations, so maybe you can at least make sense of this?

    OK. You are not a man of your word.Banno

    Whether or not I'm a man of my words depends only on whether or not I actually do as I promise. The existence of some supposed "obligation" or "holding" (whatever they are) is utterly irrelevant, if even sensible.
  • A Case for Moral Anti-realism
    DO you thinkt hat one can sincerely say "I promise to answer you but I will not answer you".

    I'll let you work through it.
    Banno

    No. Where have you derived that conclusion? My issue is with the suggestion that promises entail obligations.

    These are two distinct propositions:

    1. I promise to do this but I won't
    2. I promise to do this but I have no obligation to

    I can't sincerely assert (1) but I can sincerely (especially if I'm a nominalist) assert (2).
  • A Case for Moral Anti-realism
    The linked paper sets out an account that hows how sometimes uttering "I promise to do this" is placing oneself under an obligation.Banno

    Where?

    I can see these closely related conditions:

    7) S intends that the utterance of T will place him under an obligation to do A, and
    8) S intends to produce in H the knowledge that the utterance of T is to count as placing S under an obligation to do A

    These conditions can be satisfied even if the utterance of T does not in fact place S under an obligation to do A, e.g. if obligations do not actually exist. We can intend whatever we like, but the facts do not always accord to our intentions.

    And how does one even justify the claim that (7) and (8) are necessary conditions of promises? Perhaps (1) - (6) are sufficient.

    Of course, this all depends on what being placed under an obligation actually means, as asked above in my previous comments, e.g. are obligations abstract objects of the kind that platonists believe in and nominalists don't? Until this is answered with any clarity it isn't clear what is even being said.
  • A Case for Moral Anti-realism
    More than that. "Promises exist" means that there is an illocutionary act that involves placing oneself under an obligation. Such an act occurs in the world, not in some other domain.

    Not seeing any ambiguity.
    Banno

    The ambiguity is in making sense of the distinction between a) communicating the proposition "I promise to do this" and b) placing oneself under an obligation.

    Do (a) and (b) mean the same thing?

    If so then what is gained in asserting (b) rather than just (a)?

    If not then how do I make sense of (b), especially if I am a nominalist? Is (b) even possible if nominalism is correct? And does (a) necessarily entail (b)? How would such a claim be justified?

    If "promises exist" only means that (a) occurs then I can agree, but if it means that (b) occurs then the issue is unclear.
  • A Case for Moral Anti-realism
    It is a promise, it is an obligation.Banno

    This is an ambiguous claim.

    Are you suggesting that "I promise to do this" means "I am obliged to do this"?
    Are you suggesting that "I promise to do this" entails "I am obliged to do this"?

    Is "I promise to do this but I am not obliged to do this" in some sense a contradiction?

    People make promises. Therefore there are promises. Therefore promises exist.Banno

    This is also an ambiguous claim.

    To say that people make promises is to say that people promise to do something, and to say that people promise to do something is to say that they say something like "I promise to do this".

    Does "promises exist" mean the same thing as "people say something like 'I promise to do this'"?

    Because at least prima facie the former would suggest some sort of platonism/realism regarding the existence of abstract objects whereas the latter wouldn't.
  • Is atheism illogical?
    What possible reason could there be for not allowing for the same possibility with respect to theories about "transcendental entities"?Pantagruel

    Anything that isn't a contradiction is possible. It doesn't then follow that it is not reasonable to believe that some possibilities are true and some are false.

    It is possible that deities exist, but they don't.
  • Is atheism illogical?
    I'm asking you why a narrative that is from the limited human-centric perspective cannot both be inaccurate but also refer to something that in fact exists. Assuming which, yes, the claim that Zeus does not exist (qua "any possible deity") is not logical, that is, is not warranted.Pantagruel

    This is so vague and ambiguous as to be meaningless, i.e. illogical.

    I would say that it is reasonable to believe that Zeus does not exist, that Odin does not exist, that Shiva does not exist, that Allah does not exist, that Yahweh does not exist, and that a supernatural intelligent creator deity does not exist.
  • Is atheism illogical?


    I'm asking what you think. Is it "illogical" for to believe that the Greek, Norse, and Hindu pantheons are a fiction?
  • Is atheism illogical?


    Are these propositions insufficiently justified?

    P1. Zeus does not exist
    P2. Odin does not exist
    P3. Shiva does not exist
    P4. None of the Greek, Norse, or Hindu deities exist
  • Is atheism illogical?


    Then what specifically do you mean by "illogical" if not "contradictory"?

    Do you just mean that the proposition "no deities exist" is insufficiently justified?
  • Is atheism illogical?
    No, atheism is not illogical. The proposition "no deities exist" is not a contradiction.
  • Probability Question
    How could the multiverse be uncountably infinite?RogueAI

    I'm unsure but perhaps:

    For each real number there is a universe in which that number is selected by Michael at random, and the real numbers are uncountable.
  • Infinite Staircase Paradox
    Rather, infinitely divisibility along with the other premises entails a contradiction.TonesInDeepFreeze

    I think this is a misunderstanding of the problem.

    Say we accept that Thomson's lamp entails a contradiction; the lamp can neither be on nor off at 12:00.

    I take this as proof that having pushed a button an infinite number of times is metaphysically impossible.

    You seem to take this as proof that having pushed a button an infinite number of times is metaphysically impossible only if the premises are true.

    As an example, let's say that our button is broken; pushing it never turns the lamp on. In such a scenario we can unproblematically say that the lamp is off at 12:00. But this does not then entail that it is possible to have pushed the button an infinite number of times.

    We can imagine a lamp with two buttons; one that turns it on and off and one that does nothing. Whenever it's possible to push one it's also possible to push the other, and so if it's possible to have pushed the broken button an infinite number of times then it's possible to have pushed the working button an infinite number of times. Given that the latter is false, the former is also false.

    Having pushed a button an infinite number of times is an inherent contradiction, unrelated to what pushing the button does. Having the button turn a lamp on and off, and the lamp therefore being neither on nor off at the end, is only a way to demonstrate the contradiction; it isn't the reason for the contradiction.

    Which is also why Benacerraf's response to the problem misses the mark.

    The pseudocode I provided a month ago helps explain this:

    var isLampOn = false
    
    function pushButton()
    {
      isLampOn = !isLampOn
    }
    
    var i = 120
    
    while (true) {
    
      wait i *= 0.5
      
      pushButton()
    
    }
    
    echo isLampOn
    

    isLampOn is only ever set to true or false (and never unset) but the echo isLampOn line can neither output true nor false. This demonstrates the incoherency in claiming that while (true) { ... } can complete.

    Changing echo isLampOn to echo true does not retroactively make it possible for while (true) { ... } to complete.

    Having pushButton() do nothing does not make it possible for while (true) { ... } to complete.

    It is metaphysically impossible for while (true) { ... } to complete, regardless of what happens before, within, or after, i.e. neither of these can complete:

    Code 1
    var i = 120
    
    while (true) { wait i *= 0.5 }
    

    Code 2
    while (true) { }
    
  • 0.999... = 1
    That makes 0.999999..... = 1 just an illusion created by the notation you have decided to use. It is not a proof. In my opinion. You might have a different idea of what a proof is.Ludwig V

    Well it's not a mathematically rigorous proof as it doesn't prove each of the three steps. A mathematically rigorous proof is much more complex, as seen with TonesInDeepFreeze's answer.

    But it's a simple proof for those that accept each step individually. If you want a proof of these then that's a topic for another discussion, probably on a forum dedicated to maths.
  • 0.999... = 1
    In my book 0.9 + 0.1 = 1 and 1 - 0.1 = 0.9 and so 0.9 does not equal 1. There's a similar argument for 0.99 and 1 and so on. So far each element of 0.99999....., I have an argument that it does not equal 1. However, I see that your proof involves limits and I know that in that context words change their meanings. So I'm curious.Ludwig V



    Let's not distract from supertasks by questioning very simple mathematical facts.
  • Infinite Staircase Paradox


    That comment was directed at fishfry who claims that the lamp can turn into a pumpkin or spontaneously and without cause be on at 12:00.
  • Infinite Staircase Paradox
    Thomson’s lamp revisited makes much the same points I have made:

    P13 Some infinitist claim, however, that at tb, after performing Thomson’s supertask, the lamp could be in any unknown state, even in an exotic one. But a lamp that can be in an unknown state is not a Thomson’s lamp: the only possible states of a Thomson’s lamp are on and off. No other alternative is possible without arbitrarily violating the formal legitimate definition of Thomson’s lamp. And we presume no formal theory is authorized to violate arbitrarily a formal definition, nor, obviously to change, in the same arbitrary terms, the nature of the world (Principle of invariance). It goes without saying that if that were the case any thing could be expected from that theory, because the case could be applied to any other argument.

    i.e. the lamp can't turn into a pumpkin.

    P16 At this point some infinitists claim the lamp could be at Sb by reasons unknown. But, once again, that claim violates the definition of the lamp: the state of a Thomson’s lamp changes exclusively by pressing down its button, by clicking its button. So a lamp that changes its state by reasons unknown is not, by definition, a Thomson’s lamp (Principles of Invariance and of Autonomy).

    i.e. the lamp is on if and only if the button is pushed (when the lamp is off) to turn it on (and not then pushed to turn it off).
  • Infinite Staircase Paradox
    Next would be to examine whether your inference is correct that the problem shows that time is not infinitely divisibleTonesInDeepFreeze

    The simple reasoning is that if time is infinitely divisible then pushing a button an infinite number of times within two minutes is theoretically possible. Pushing a button an infinite number of times within two minutes entails a contradiction and so isn't theoretically possible. Therefore, time is not infinitely divisible.

    Although I think perhaps this variation of Zeno's paradox might be better at questioning the infinite divisibility of spacetime.
  • Gödel's ontological proof of God


    I think you've misunderstood these:

    1. ◇∃x(F(x) ∧ A(x))
    2. ◇∃x(F(x) ∧ ¬A(x))

    They say:

    1. It is possible that there exists some X such that X is the only unicorn and is male
    2. It is possible that there exists some X such that X is the only unicorn and is not male

    They are not inferences but independent premises and might both be true.

    My argument is that we cannot then infer these:

    3. ◇□∃x(F(x) ∧ A(x))
    4. ◇□∃x(F(x) ∧ ¬A(x))

    Which say:

    3. It is possibly necessary that there exists some X such that X is the only unicorn and is male
    4. It is possibly necessary that there exists some X such that X is the only unicorn and is not male

    Under S5 they cannot both be true.

    This matters to modal ontological arguments because (3) and (4) are equivalent to the below:

    3. It is possible that there exists some X such that X is the only unicorn and is male and necessarily exists
    4. It is possible that there exists some X such that X is the only unicorn and is not male and necessarily exists

    The switch from "possibly necessary that there exists some X" to "possible that there exists some X such that X necessarily exists" is a sleight of hand. It is used to disguise the fact that asserting the possible existence of God – where necessary existence is a property of God – begs the question.
  • Gödel's ontological proof of God
    Cool. Well if it helps, I've re-written that first comment to correct the typos and to hopefully be clearer.
  • Gödel's ontological proof of God
    I hope it won't be too long that I'll have time to resume going over your argument with the emendations.TonesInDeepFreeze

    Are you waiting on me for something else or are you saying that you're currently too busy to examine what I've said?
  • Gödel's ontological proof of God
    Also, you have a modal operator after a quantifier.TonesInDeepFreeze

    Yes, good catch. I should have used ◇□∃xP(x).

    Am I correct that by "we cannot assume pEx(nPx) is true for any logically consistent Px" you mean "For all consistent Px, we have that pEx(nPx) is not logically true"?TonesInDeepFreeze

    What I am saying is that ◊∃xP(x) ⊬ ◊□∃xP(x), i.e "it is possible that X exists" does not entail "it is possibly necessary that X exists".
  • Infinite Staircase Paradox
    When you say "there are no spontaneous, uncaused events," you are ignoring the physically impossible premises of the problem.fishfry

    No I'm not. I accept that one of the premises of the thought experiment is physically impossible. That doesn't then mean that we cannot have another premise such as "there are no spontaneous, uncaused events".

    You seem to think that because we allow for one physical impossibility then anything goes. That is not how thought experiments work.

    It is physically impossible for me to push a button 10100100 times within one minute, but given the premises of the thought experiment it deductively follows that the lamp will be off after doing so. Your claim that the lamp can turn into a plate of spaghetti is incorrect.
  • Gödel's ontological proof of God
    It would help if you would give one self-contained argument with transparent inferences from start to finish.TonesInDeepFreeze

    I think the previous argument did that? Perhaps you could let me know which line(s) you'd like me to explain further?
  • Gödel's ontological proof of God


    The explanation of the argument here presents the problem more clearly.
  • Infinite Staircase Paradox
    I want to get back to looking at this more closely, but in the meantime, do you consider your presentation equivalent with Thomson's statement of the problem?TonesInDeepFreeze

    Yes.
  • Gödel's ontological proof of God


    S5 has as an axiom that ◊□p ⊢ □p.

    Therefore, under S5, these cannot both be true:

    1. ◊□q
    2. ◊□¬q

    Therefore, under S5, this is not true:

    3. ¬□¬p ⊢ ◊□p

    This then relates to the post above.

    Assuming that (a) means (b), (b) needs to be justified. Given that (3) is false, this is false:

    4. ¬□¬∃xC(x) ⊢ ◊□∃xC(x)

    So ◊□∃xC(x) must be justified some other way for a modal ontological argument to work.
  • Gödel's ontological proof of God


    So we both agree that modal ontological arguments like Gödel's fail to prove the existence of God.
  • Gödel's ontological proof of God


    See the opening post, where Gödel's argument is presented. See line C:

    mzhrHsL.png

    These are the kinds of modal ontological arguments that I am addressing.
  • Gödel's ontological proof of God
    The implications of the natural English propositions and the implications of the modal logic propositions diverge drastically, and it would be silly to prefer the modal logic to the natural English. That would be to let the tail wag the dog, as I arguedLeontiskos

    I'm addressing modal ontological arguments. These arguments try to use modal logic to prove the existence of God.

    No one thinks creation was necessary. It seems that you have gotten your theology from Richard Dawkins.Leontiskos

    It was just an example. Replace with "omnipotence", "omniscience", or whatever you want.
  • Gödel's ontological proof of God
    Then the modal logic fails to translate, because <it is possible that there exists a necessary being> does not mean <it is possibly necessary that there is a being>.Leontiskos

    Modal ontological arguments try to use modal logic to prove the existence of God. In particular, they use S5's axiom that ◊□p ⊢ □p.

    At their most fundamental, their premises take the following form:

    1. X is God if and only if X necessarily exists and has properties A, B, and C1.
    2. It is possible that God exists.

    To prevent equivocation, we must use (1) to unpack (2), reformulating the argument as such:

    1. X is God if and only if X necessarily exists and has properties A, B, and C.
    3. It is possible that there exists some X such that X necessarily exists and has properties A, B, and C.

    The phrase "it is possible that there exists some X such that X necessarily exists" is somewhat ambiguous. To address this ambiguity, we should perhaps reformulate the argument as such:

    1. X is God if and only if X necessarily exists and has properties A, B, and C.
    4. It is possibly necessary that there exists some X such that X has properties A, B, and C.

    We can then use S5's axiom that ◊□p ⊢ □p to present the following modal ontological argument:

    1. X is God if and only if X necessarily exists and has properties A, B, and C.
    4. It is possibly necessary that there exists some X such that X has properties A, B, and C.
    5. Therefore, there necessarily exists some X such that X has properties A, B, and C.

    This argument is valid under S5. However, (4) needs to be justified; it is not true a priori.

    If, as you claim, (3) and (4) are not equivalent, then prima facie one cannot derive (5) from (3), and so something other than S5 is required.

    1 The particular properties differ across arguments; we need not make them explicit here.
  • Gödel's ontological proof of God
    Hence, if it is not necessary that there is a god, then there is no god.Banno

    Both this claim and the claim that God is necessary amuse/confuse me.

    Imagine that some intelligent, all powerful, all knowing, creator of the universe actually does exist, but that because it doesn't necessarily exist then we refuse to call it God, as if the name we give it is what matters.
  • Gödel's ontological proof of God


    So, X is God if and only if X has all positive properties.
    Necessary existence is a positive property.
    Being all powerful is a positive property.
    Being all knowing is a positive property.
    Therefore, X is God if and only if X necessarily exists, is all powerful, is all knowing, etc.

    Now, what does "God possibly exists" mean? In modal logic we would say ◊∃xG(x) which translates to "it is possible that there exists an X such that X is God."

    Using the definition above, this means:

    It is possible that there exists an X such that X necessarily exists, is all powerful, is all knowing, etc.

    But what does this mean? In modal logic we would say ◊□∃x(P(x) ∧ K(x) ∧ ...) which translates to "it is possibly necessary that there exists an X such that X is all powerful, is all knowing, etc."

    Notice how "it is possible that there exists an X such that X necessarily exists ..." becomes "it is possibly necessary that there exists an X such that X ...". This step is required to make use of S5's axiom that ◊□p ⊢ p. But it also removes necessary existence as a predicate.

    All we are left with is the claim that it is possibly necessary that there exists an X such that X is all powerful, is all knowing, etc. This is a claim that needs to be justified; it isn't true by definition.
  • Gödel's ontological proof of God
    To me, this is circumvented by D1, defining God as having all positive properties.Lionino

    Here are three different claims:

    1. If X is God then X has all positive properties
    2. If X has all positive properties then X is God
    3. X is God if and only if X has all positive properties

    Which of these is meant by "God is defined as having all positive properties"?
  • Gödel's ontological proof of God
    The true value of Gödel's work is that it manages to prove that atheists will reject a mathematically unobjectionable proof if it proves something that they disagree with.Tarskian

    It's not a mathematically unobjectionable proof.

    In its simplest form it is:

    ◊p
    p ≔ □q
    ∴ ◊□q
    ∴ q

    But given the second line, this is equivalent to:

    ◊□q
    ∴ q

    Which begs the question.
  • Gödel's ontological proof of God


    I'll translate it into English for ease.

    Neither of these are contradictions:

    1. There exists a unique creator god who performs miracles
    2. There exists a unique creator god who does not perform miracles

    But they cannot both be true. Therefore, under S5, at least one of these is false:

    3. It is possibly necessary that there exists a unique creator god who performs miracles
    4. It is possibly necessary that there exists a unique creator god who does not perform miracles

    Therefore, we cannot just assume that because some X is not a contradiction that it is possibly necessary. We need actual evidence or reasoning to support such a claim.
  • Gödel's ontological proof of God


    ◊~p → □◊~p (5 axiom)
    ◊~p → ~◊~◊~p (Definition of □)
    ~~◊~◊~p → ~◊~p (Contraposition)
    ◊~◊~p → ~◊~p (Double negation)
    ◊□p → □p (Definition of □)
  • Infinite Staircase Paradox
    Question: Do you put the same constraint on Cinderella's coach? Why or why not? Want to understand your answer.fishfry

    I don't understand your question.

    Asking me why I'm using P1 as a premise is as nonsensical as asking me why I'm using P2 as a premise. They are just the premises of the thought experiment. The intention is to not allow for the lamp to be off, for the button to be pushed just once, turning the lamp on – and then for the lamp to be off.

    We are trying to understand what it means to perform a supertask, and so we must assert that nothing other than the supertask occurs. There are no spontaneous, uncaused events. If we cannot make sense of what the performance of the supertask (and only the supertask) causes to happen to the lamp then we must accept that the supertask is metaphysically impossible.
  • Infinite Staircase Paradox
    So I don't see the point of your argument hereLudwig V

    Benacerref claimed that the supertask being performed and then the lamp being on is not a contradiction. I am trying to prove that it is (or rather that Thomson already proved this).

    The lamp cannot be on after the performance of the supertask and cannot be off after the performance of the supertask – precisely because there is no final button push and because the lamp cannot spontaneously and without cause be either on or off.

    The pseudocode I provided before shows this. Its logic does not allow for echo isLampOn to either be determined to output true or false or to arbitrarily output true or false. Therefore, we must accept that it is impossible in principle for while (true) { ... } to ever complete.

    And so we must accept that it is impossible in principle for a supertask to be performed.