OK. Another way to put it is that 'observe' and 'know' are achievement verbs (Gilbert Ryle's term). You can't observe what isn't there or know what is...
You can only observe that it is raining if it is raining (if that's what you're referring to). If I know that it's raining because I observed rain, th...
Yes. So a robot could be built that had wings and feathers. In that sense it would be like a bird. But it would not be a bird even if we couldn't easi...
A handy feature I just found if you want to see the source of an equation in another post. Right-click on the math and select "Math Settings | Math Re...
I think so. Yes and renaming ¬f to g makes that visually clear: \begin{align}(s\wedge g(\ulcorner s \urcorner)) \vee (\neg s\wedge \neg g(\ulcorner s ...
Glad we agree! Yes, they are distinguishable. But we seem to have different ideas about what your duck definition can include. The common definition f...
Still thinking about it, but a couple more things. When you consider A, I think you can omit the s1 discussion and just note that A is an instance of ...
I think the negation of the lemma needs to contain a disjunction as follows (since for the negation every tuple must be either (true,false) or (false,...
OK. OK. So we can investigate why Reason adopts a knowledge attitude towards some beliefs and not others, such as the 'no fluke' condition above. Thus...
So Reason has no reasons, as it were. She is inscrutable. It seems that you regard human reason as a kind of intuition or feeling that derives (howeve...
How would we distinguish between those beliefs Reason approves of and those she does not? Or to put it another way, why does Reason approve of the bel...
The issue is that we're trying to empirically find out what knowledge is (or, linguistically, how people use the term), not legislate it. A human acto...
I dispute 1 and 2. Per premise 1, I can point to people making assertions. But you can't point to reason making assertions since it is an abstract ter...
That's an unusual usage. As defined here, "mind" ordinarily refers to a faculty or ability of a person, not that it is a person. Anyway since they're ...
Mind isn't a person. Mind is an abstraction that refers to a person's ability to think and reason. Only a person can assert things. You seem to be tre...
Isn't that like saying that the solution to world peace is what Reason asserts it is? Also capitalized Reason is poetic, but what does it refer to? Ou...
You would just provide appropriate context if need be. For example, include an asterisk next to the correction and at the bottom of the post note the ...
Some people won't bother reading that far if they encounter glaring mistakes. Correcting such mistakes just makes it easier for your readers. I know. ...
It could be useful to your readers if you edited your original OP with the corrected figure. And also provided a link to a relevant scientific study o...
A possible analogy: The rules of chess specify that players can only move a bishop along the diagonal. Moving the bishop vertically would be invalid. ...
That is a consequence of how you've defined the system. It seems to me that what you're pointing out is just that a predetermined initial state is inc...
On trivialism, the statement of mine that you are disagreeing with is trivially true. So your disagreement assumes non-trivialism (i.e., you think my ...
As I see it, if the world seemed inconsistent then that would point to a problem of representation, not that the world was inconsistent. That's the ap...
If there is a contradiction, it is only in how the system is being represented. In this scenario, person B has complete information about the system w...
It depends on the realist - what they think about concrete or physical things doesn't necessarily apply to abstract objects (or universals). For examp...
No, we would just look for ways to model the world that avoided inconsistency. Which is just what occurs in quantum mechanics where the state of a par...
Right, the argument shows that one can't know that realism is true (via contradiction). Interestingly, we can see what is going on here via the earlie...
Agreed. The relevant issues to my mind would be about what logical consequences follow from it (e.g., is it coherent or does it lead to inconsistency ...
I'm going to translate your argument in terms of something concrete. Consider an apple on Bob's kitchen table, which I'll abbreviate as 'the apple'. P...
If you lived in a world where nothing followed necessarily from anything else, then MP wouldn't apply. Perhaps, for example, a quantum vacuum where pa...
Yes, RQM is a high-level abstraction that preserves nice features like locality, theory completeness (i.e., no hidden variables or ad hoc changes) and...
No. Everett developed his interpretation prior to Lewis' and Kripke's work. And the earlier Copenhagen Interpretation rejected counterfactual definite...
None, it seems to me, since they're describing very different things. "Possible worlds" is a tool for modeling abstract hypotheticals or counterfactua...
Yes. So I think there's a lot of baggage that comes along with accepting the Gödel sentence in one's logic system. I suggest that the sentence is not ...
Thanks for your detailed reply - definitely helpful for working through this. However that Wikipedia link doesn't provide an external reference and a ...
Going back to this again. Consider a non-standard model where ~G is true. Since ~G says that G is provable then, if ~G is true, G is provable. Now ~G ...
But we're discussing non-standard models where ~G is true. Since ~G says that G is provable then, if ~G is true, G is provable. However since G isn't ...
Yes, I get that provability means true (or false) in all models. What I don't get is why the negation of G shouldn't be interpreted as saying that G i...
Working through the logic, G is: This sentence is not provable So ~G is: The sentence "This sentence is not provable" is not true Now ~G (as with G) i...
OK. So, per the earlier Wikipedia quote, what does it mean that the Godel sentence (G) is false in some (non-standard) model of Peano arithmetic? Sinc...
Thanks for the explanations. OK. Does that just mean that non-standard models of Peano arithmetic are inconsistent? Or is there more to it than that? ...
OK. What I'm suggesting is that an arithmetic sentence could be defined as only being true (or false) if it is, in principle, provable from axioms (or...
Returning to this... Yes, in effect the diagonal lemma can generate the Liar sentence, as follows: This sentence is not true Which, in turn, leads to ...
A belated thanks for your reply! I've spent some time working through the proof of the diagonal lemma and do have a few questions. However I thought I...
If no true but unprovable X has been found to satisfy "X ? isNotProvable(%X)", then why should we consider it to be a satisifiable definition? Also, w...
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