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Nagase

['Member']Joined: October 28, 2016 at 15:00Last active: February 21, 2026 at 14:02None discussions197 comments
Location: São Paulo, Brazil

Bio

I'm a philosophy student with great interest in logic, mathematics, feminism, and Kantian philosophy.

Comments

A couple of remarks: 1) The logical positivists were influenced by the Neo-Kantians, but weren't themselves Neo-Kantians. So Neo-Kantian worries do no...
August 29, 2021 at 20:29
Just to be clear, I'm not saying that Popper is irrelevant or whatever. It's just that popular accounts of science tend to portray him as being the be...
August 29, 2021 at 18:19
First, I would like to dispute that "fallibilism" is any better criteria of significance than verificationism, or even that it is mainstream today. It...
August 29, 2021 at 16:06
Incidentally, I don't think boundary policing ("Is philosophy a science?") is much helpful. Philosophy is whatever is practiced at philosophy departme...
August 24, 2020 at 20:40
I'm happy that my posts have been helpful, though I'm not too sure if I'm representative of academic philosophy---I'm finishing my PhD in a third-worl...
August 24, 2020 at 20:37
I take it that there are two ways of interpreting your objection to the use of formal systems. One is a ban on the significance of formal systems tout...
August 24, 2020 at 16:45
You said that the sentence "This sentence is not false" was meaningless. I then asked, supposing it meaningless, why it is meaningless. Notice that th...
August 24, 2020 at 15:48
A bit of both, I suppose. I'm following Scharp (and Ripley's account of Scharp), here (this is not meant as an endorsement of his position, I'm just t...
August 24, 2020 at 01:11
I don't have much to add besides what I have already mentioned in my first reply to you. Take arithmetic, for instance. It is not difficult (though it...
August 23, 2020 at 23:15
Let us suppose you are right and the Liar is meaningless. This raises the question: why is it meaningless? Let us suppose, for definiteness, that the ...
August 23, 2020 at 22:32
In his book (p. 81), Scharp mentions that the following triad is inconsistent for a logic L: (i) L accepts modus ponens and conditional proof; (ii) L ...
August 23, 2020 at 18:55
Self-referentiality may seem like a problematic concept, but Gödel, Tarski, and Carnap have shown that it is possible to construct a self-referential ...
August 22, 2020 at 23:00
If a theory is such that: (i) it has a reasonable proof system (i.e. one can check by an algorithm whether or not a sequence of formulas is a proof) a...
August 04, 2020 at 20:10
If by G you mean the Gödel sentence, then, yes, the algorithm will miss it. But that's because the algorithm lists all the theorems of PA, and the Göd...
August 04, 2020 at 20:02
Yes, there is a proof of the consistency of PA, though whether or not it is finitistically acceptable is debatable. Gentzen proved that the consistenc...
August 04, 2020 at 18:58
I'll be very explicit, then: there is, in fact, an algorithm that lists all and only the theorems of PA. This algorithm therefore provides an exhausti...
August 04, 2020 at 18:51
I think you are focusing too much on the fact that theoremhood is not strongly representable in PA, with the consequence that you are ignoring the fac...
July 30, 2020 at 11:19
A couple of observations: (1) First, note that the theorem, in the form I stated, is a bit more general, since it does not rely on any specific unprov...
July 26, 2020 at 01:54
Don't mention it. I'm glad this has been useful to someone...
July 24, 2020 at 19:54
Well, proof is relative to a system of axioms. That is, we usually define proof, relative to a theory T, as follows: a sequence of statements A1, ...,...
July 24, 2020 at 19:53
There would only be a contradiction if Gödel claimed that his own theorem was unprovable. Fortunately, he was not an idiot, and therefore did not clai...
July 24, 2020 at 18:25
There is no contradiction. One can hold that proof is necessary to establish truth, yet hold that it is not necessary for truth (cf. my point about un...
July 24, 2020 at 15:54
You seem to be confusing knowledge with truth. Obviously, to establish a proposition as true, I need to, well, establish as such. And, in mathematics,...
July 24, 2020 at 15:21
(1) Gödel (well, Gödel, Church, Tarski, Rosser, etc.) showed a bit more than what you are implying. He showed that, for any consistent system containi...
July 24, 2020 at 15:18
I don't think Löb's theorem supports the constructivist position. That's because truth is generally taken, prima facie to obey the capture and release...
July 24, 2020 at 14:10
In my (philosophy) department (here in Brazil), undergrads are generally introduced to the basics of logic or formal reasoning, say through Priest's A...
July 22, 2020 at 13:07
Refer to my reply to for a clearer sketch of why truth is not provability, and which has nothing to do with G or whatever. And, again, you're evading ...
July 22, 2020 at 13:00
Let me put it this way. Suppose truth were equal to provability (or even just extensionally equivalent). Then any algorithm for enumerating all the th...
July 22, 2020 at 12:54
Let us suppose that everything you say is true. This still does nothing to address two facts: (1) the set of true formulas is not arithmetically defin...
July 21, 2020 at 18:28
Unfortunately, from the fact that provability is sufficient for truth, it does not follow that it is necessary for truth (in general, being a sufficie...
July 21, 2020 at 11:29
There is a better proof of Gödel's theorems that considerably clarifies the situation. It relies on two other theorems: (1) Gödel's proof that the set...
July 20, 2020 at 15:28
(1) I'll give two examples that I think can be illuminated by considering economic models. Consider what is generally taken to be Smith's doctrine of ...
July 06, 2020 at 18:02
For Kaplan, the two utterances of "Bob" that you described are not occurrences of the same word, but of different words that just happen to share the ...
July 06, 2020 at 17:25
(1) On idealization: yes, I do think it is a successful strategy in most, if not all, sciences. Note that idealization is not used (just) to isolate a...
July 06, 2020 at 01:20
A couple of points: (1) First, I'd just like to second 's claim that Priest (and most dialetheists I know) does not claim that all contradictions are ...
July 06, 2020 at 01:11
I think the two discussions (about economics, about punishment) are a bit different, perhaps in the direction gestured at by . In the case of rational...
July 01, 2020 at 19:37
I don't understand. Consider two actual (in contrast to potential?) circles on the Cartesian plane, say, one described by x^2+y^2 - 1=0 and the other ...
June 30, 2020 at 19:32
I don't personally think there is any property that is common to every two pair of objects (except in a gerrymandered way), but let us leave this to t...
June 30, 2020 at 18:06
Again, from the fact that some (perhaps all) universals, like "circleness" (the universal), are abstract, it does not follow that every abstract entit...
June 30, 2020 at 16:02
It seems that you are confusing abstractness with being a universal. Some may defend that universals are abstract (but not all do: some people defend ...
June 30, 2020 at 13:35
Well, for starters, I think that you vastly overestimate philosophy's impact on the world. The revolutions you cite were definitely not the "direct co...
May 24, 2020 at 03:46
Well, I thought that you wanted your principle as a solution to a problem described in the OP. If the relation between them is irrelevant to you, ok, ...
April 13, 2020 at 23:41
Yes, we use folk psychology all the time in interacting with other people (interestingly, this is now studied under the heading of "theory of mind" an...
April 13, 2020 at 23:39
But then, how can he justify that what is beyond the physical cannot be perceived? Surely this a metaphysical claim about the nature of whatever it is...
April 13, 2020 at 21:07
Well, according to you, he is saying that what is not perceivable is not physical, which seems a pretty strong connection between perception and reali...
April 13, 2020 at 20:34
Sure, but Hume is not denying that some things can be perceived, nor he is denying that there is a connection between perception and reality. So, agai...
April 13, 2020 at 20:27
I strongly recommend reading Kenneth Mander's papers in The Philosophy of Mathematical Practice, edited by Paolo Mancosu (you can easily find the volu...
April 13, 2020 at 20:24
You asked about whether we can scientifically study people's minds, with the specific challenge that we somehow do not have access to the inside of pe...
April 13, 2020 at 19:25
I don't see the relevance of the principle to the problem. If something can't be perceived, then no one can perceive it, so, ipso facto, there will be...
April 13, 2020 at 19:11
Some of these ideas are captured by modal logic, especially counterfactual logics (cf. Lewis's theory of causation, for instance). But I'm not sure wh...
April 12, 2020 at 21:32