If you reject "objective reality", is there any interpretation other than Many Worlds which is acceptable? — Metaphysician Undercover

I think the Copenhagen interpretation is not compatible with the usual folk notion of 'objective reality'. It denies that there is any fact of the matter about where a particle is between observations.

What troubles me about this is that, on my understanding of QM, wave function collapse is non-measurable. It is a matter of interpretation, of ontology, not something that can be measured - so strictly speaking it isn't even part of QM. So either this experiment implies less than the MIT pop summary says it does, or I am going to have to radically revise my understanding of QM.

I've downloaded the full paper from arxiv and will see what I can make of it.

I think to resort to Schodinger’s famous simile, it’s as if Bob observes a live cat, and Alice a dead one - and they’re both right. — Wayfarer

Is that what the paper does - create a situation where both observers have the same level of detail in their knowledge, and the details contradict each other? That would be a much stronger result than anything contemplated in Wigner's thought experiment, which seems to rely on a belief in 'objective collapse' to have any interest at all..

Physicists have long suspected that quantum mechanics allows two observers to observe different, conflicting realities. — Wayfarer

I don't believe in objective reality so this is a bit moot for me. But I'm very interested in QM so I feel the need to comment.

I think it's overstating to say that Wigner and his friend experience conflicting realities. Rather, the friend just has more information than Wigner. The difference can be interpreted as purely epistemological. Wigner knows that his friend knows which way the spin goes, but Wigner doesn't know which way. So Wigner models the lab as a superposition while the friend does not.

I can't see anything new in Wigner's thought experiment. To me it sounds the same as observing that, if we put another cat in the box with Schrodinger's first cat, but the two are separated by a transparent, airtight wall, so that the second cat doesn't get poisoned if the vial breaks, then the second cat (Wigner's friend) knows whether the first cat is alive or dead, but Schrodinger (Wigner) does not.

I can't see what there is to experiment on. I suppose I'll have to read the paper to find out, but I don't know when I'll get time to do that..

This is just lazy thinking like saying “philosophy is a waste lets just live, man!” — kudos

It's not at all like that. Your example is of a weak justification to not do something. Not doing something is consistent with the notion of laziness.

Wayfarer is talking about doing something - in this case religious practice. Whatever criticisms one might wish to make about certain forms of religious practice, it's hard to see how laziness can be one of them. It's a lot easier to stay in bed of a morning than to get up and go to the mosque, church or temple.

Been looking at some Karl Rahner writing last few days. So in speaking to a person who claimed they had never experienced God.

"I don’t believe you; I just don’t accept that. You have had, perhaps, no experience of God under this precise code-word God but you have had or have now an experience of God – and I am convinced that this is true of every person." — Rank Amateur

I'm on the side of those that deny that religious belief is necessarily irrational, in this discussion.

But I have a viscerally negative reaction to statements like that attributed to Rahner.

The level of conceit it must take to tell other people what they think and feel is simply mind-boggling.
To go further and say that the assertion applies to every single one of the seven billion plus people in the world defies comprehension.

Let's review your argument:

You put forward as one of the reasons why you are opposed to social pressure against certain types of speech, that you are opposed to mob mentality.

You then say that for you 'mob mentality' means something that other people describe as cooperation.

Then you say that words to the effect of 'towards applying social pressure against certain types of speech' are implicitly appended to 'cooperation', because of the context.

With those explanations, the reason you gave why:
....you are opposed to social pressure against certain types of speech
is that
.... you are opposed to cooperation towards applying social pressure against certain types of speech.

Do you see the problem?

So?

many people acting in conjunction with each other to a particular end, and that's what I'm referring to by "mob mentality." — Terrapin Station

Under that definition, a group of Amish collaborating to raise a barn is an instance of mob mentality. It's what most people call 'cooperation'.

Being anti-cooperation is an unusual stance.

t's related to me (1) being a free speech absolutist, (2) being against controlling others as much as possible, (3) being against mob mentalities, (4) being pro laissez-fairism, and (5) not being in favor of sanctions in response to "hurt feelings." — Terrapin Station

1, 2 and 4 are consistent with the conclusion. It sounds like you are a libertarian. Fair enough - it's just a different ethical system.

3 and 5 are not relevant though, as disapproval of things like racist or sexist speech is not based on the potential for hurt feelings and, until we see mobs out there actually harming people that speak racist or sexist things, claims of 'mob mentality' are baseless hyperbole.

In my view, yes [there is something wrong with applying social pressure against somebody's expression]. — Terrapin Station

I am curious to hear about how you come to that view. Is it derived from some set of moral principles, or is it more just a feeling? If principles, I'd like to hear about what they are and how the derivation proceeds.

People aren't letting others' expressions stand as written, but are also applying various social pressures, are they not? — Bitter Crank

Nice work. That is a sentence that's easy to respond to.

Is there something wrong with applying social pressure against somebody's expression? Well, as far as I can see, everybody does it, so I can't see how anybody could seriously suggest there is something wrong with it.

If somebody is swearing loudly and continuously in a busy shopping street, the police will eventually pick them up for public disorder. If somebody does the same in a social group like a school or club, they will face, at a minimum, the disapproval and dislike of members of the group, and maybe expulsion.

If a person says that Mexicans are drug dealers and rapists, or just lazy and stupid, people will send that person to Coventry - except in the US, where they'll elect them president, or the UK where they'll give them a lucrative contract to talk about motor cars on television.

Social pressure is how society manages to maintain civilised modes of interaction - what we call politeness and civility. Like any tool, it can be misused, but that is the fault of the misuser. It doesn't mean there's anything wrong with the tool.

Real joy derives from feeling a sense of purpose beyond the sounds of the tea kettle and the fluttering of the birds outside. — Hanover

'Real joy' sounds a bit like a 'true scotsman'. I think both un's and your descriptions fit within the generally understood concept of joy.

People aren't just letting others' expression be and not applying various social pressures, etc., are they? — Terrapin Station

I don't want to try to control your expression, but I feel obliged to point out that asking questions with such fundamental grammatical errors that they are incomprehensible is not conducive to constructive discussion.

Baby boomers being fooled is a pity.

Fortunately, as St Roger of Daltrey prophesied in 1971, we won't be fooled again!

Excellent, well-researched post. Thank you.

One person's political correctness is another's basic good manners.

You will need to be more specific about what form of political correctness you object to - giving examples - if a useful discussion is to occur.

It turns out the thread is actually about a completely different problem. The title is a misnomer.

Here you go:

P1: ∃x(Fx ∧ ∀y(Fy → y=x) )
P2: ∃x(Gx ∧ ∀y(Gy → y=x) )
P3: ∀x¬(Fx ∧ Gx )

C1: ∃x∃y[ (
(Fx ∨ Gx)
∧ (Fy ∨ Gy)
∧ (x≠y) )
∧ ∀z((Fz ∨ Gz) → (z=x ∨ z=y) )]

We write ‘a’ for an object that satisfies P1 and ‘b’ for an object that satisfies P2.
So we have:

3: Fa ∧ ∀y(Fy → y=a) (∃ elimination, P1)
4: Gb ∧ ∀y(Gy → y=b) (∃ elimination, P2)

which we split into

5: Fa
6: ∀y(Fy → y=a)
7: Gb
8: ∀y(Gy → y=b)

9: ¬(Fa ∧ Ga ) (substitution of a into P3)
10: ¬(Fb ∧ Gb ) (substitution of b into P3)

Next:
11: ....Fb (Cond Hyp)
12: ....Fb ∧ Gb (9, 7)
13: ....Contradiction (10, 12)
14: ¬Fb (close Cond Proof, negating 11)

15: ....Ga (Cond Hyp)
16: ....Fa ∧ Ga (15, 5)
17: ....Contradiction (9, 16)
18: ¬Ga (close Cond Proof, negating 15)

We hypothesise that a and b are objects that satisfy the existence claim in C1.
We’ll prove the conjuncts in C1 in turn, for the case x=a, y=b.

19: Fa ∨ Ga (5, OR introduction) [1st conjunct proven]
20: Fb ∨ Gb (7, OR introduction) [2nd conjunct proven]

21: ....a=b (Cond Hyp)
22: ....Ga (7, 21, substitution on =)
23: ....Fa ∧ Ga
24: ....¬(Fa ∧ Ga) (P3, specification of x=a)
25: ....Contradiction (23, 24)
26: a ≠ b (close Cond Proof, negating 21) [3rd conjunct proven]


27: Fz → z=a (specify y=z in 6)
28: z ≠ a → ¬Fz (reversal of 27)
29: Gz → z=b (specify y=z in 8)

31: .... Fz ∨ Gz (Cond Hyp)
32: ........ z ≠ a (Cond Hyp)
33: ........ ¬Fz (Modus Ponens 28, 32)
34: ........ Gz (31, 33, OR elimination)
35: ........ z=b (MP 29, 34)
36: .... ¬ (z=a) → (z=b) (close Cond Proof 32-35)
37: .... z=a ∨ z=b
38: Fz ∨ Gz → z=a ∨ z=b (close Cond Proof 31-37) [4th conjunct proven]

39: (Fa ∨ Ga) ∧ (Fb ∨ Gb) ∧ a ≠ b ∧ (Fz ∨ Gz → z=a ∨ z=b) (AND introduction 19, 20, 26, 38)
40: ∃x ∃y (Fx ∨ Gx) ∧ (Fy ∨ Gy) ∧ x ≠ y ∧ (Fz ∨ Gz → z=x ∨ z=y) (∃ introduction 39)

Yes that sounds good. I have started a thread asking for recommendations.

It's a good question, often asked and unfortunately one for which I do not have an answer, as I did not use textbooks in learning logic. It would be great if we had a list of recommended textbooks pinned to the top of the Logic and Mathematics forum, so that all could benefit from it. I'll start a thread there inviting recommendations. If we get some good ones (ie recommendations that don't have lots of other people saying the text is terrible), we can pin it.

Very roughly, a formal language is (1) a set of symbols that can be used, together with (2) a set of rules for how they can be strung together to make syntactically correct statements and (3) a set of rules for how deductions can be made.

A theory T in a language L is a set of syntactically valid statements in L such that any statement that can be deduced from a finite collection of statements in T, using the deduction rules of L, is also in T.

We say a collection A of statements in L is a set of 'axioms' for T if T is the intersection of all theories containing A. We say 'T is generated by A'.

The set of tautologies in L is the theory generated by the empty set (ie no axioms).

First let me write it out in a way that's a bit easier to read - for me at least:

"If exactly one object has property F and exactly one object has property G and no object has both properties, then there are exactly two objects that satisfy one or more of the two properties"

It sounds like it should be true.

Look up any logic text. There is no shame in not knowing the difference between a theory and a language. Most people don't. But it is inappropriate to criticise other posts in a discussion on logic, based solely on your lack of knowledge of some of the basic building blocks of symbolic logic.

No they are theories, expressed in the language of mathematics. The distinction is critical.

I usually use \to for $\to$ rather than $\Rightarrow$ because it is quicker to write, and more commonly used in logic texts. It's worth noting that changing to lower case the first letter of the code for any of the arrows above changes the symbol from a double to a single arrow, eg
\leftrightarrow for $\leftrightarrow$ instead of \Leftrightarrow for $\Leftrightarrow$

Other signs I've found useful in logic are \vdash for $\vdash$
\bigcup_{j=1}^n for $\bigcup_{j=1}^n$
\bigcap_{j=1}^n for $\bigcap_{j=1}^n$

\bigvee_{j=1}^n for $\bigvee_{j=1}^n$

\bigwedge_{j=1}^n for $\bigwedge_{j=1}^n$

A Tautology is a feature of a language, not a theory. Peano arithmetic is a theory, so something being true in Peano arithmetic does not make it a tautology of the language in which it is written. In the very same language the following are correct:

1+1=0

in binary arithmetic, and

1+1=1

in Boolean arithmetic.

“1”, “+”, “=“, and “2” have specific meanings by convention. So, “1+1=2” is a tautology. It has to be true given the meanings of the terms used. There is nothing to prove. — Noah Te Stroete

The statement of "1+1=2" in Peano arithmetic is:

S0 + S0 = SS0

Because "1" means S0 and "2" means SS0. S is the 'successor' function.

That is not a tautology. It has to be proved. The proof, as I recall, is not long.

This discussion was merged into It is life itself that we can all unite against

Objects move through space, not through space-time. To move through space-time would require an additional time dimension with respect to which that motion was measured. So we'd need five dimensions all up.

Rather, the motion of an object is represented as a fixed curve in the 4D spacetime manifold.

I don't believe in utopian visions. We are not heading towards heaven on Earth. But I do think that things have been getting generally better in the West since medieval times. The progress is very slow and sometimes we go back for a while. The current rise of national chauvinism in many countries, and attempts to justify racism and sexism, are examples.

I am not so sanguine about some other cultures. It is especially disheartening that many countries with islamic majorities have been becoming more theocratic and repressive. In some cases, like Turkey and Indonesia, the theocratic element is new. In others like Pakistan, it was always there but whereas it was waning up to about 1980, it has been on the rise since.

Russia is another setback. After a decade or so of optimism following the fall of the Soviet Union, we now seem to well on the way back to repression that is not very different from what was there pre-1989.

In any case, no matter how kind a civilisation becomes, it's still vulnerable to external shocks, be they global warming or an asteroid impact, which could send them back to a post-apocalyptic, everyone for themselves, situation, from which they need to gradually extricate themselves over the centuries. Asimov's 'Nightfall' depicts a world in which that collapse happens with monotonous regularity over millennia.

I don't expect a consensus for voluntary extinction to ever be reached. It is only ever tiny minorities that have such views. For that to change, the genetic makeup of humans would need to change, and it's hard to see how that could happen in a way that makes that a goal, Hegel notwithstanding.

We are thrown into this existence, and have to make the best of it. Some individuals may choose on ethical grounds not to procreate - to throw others into existence - but I think it will be rare enough that it makes no difference to the big picture of human history.

von Hartmann had some interesting insights in this regard- the illusion is that happiness can be had in the present, the hereafter, or a future utopian state. So where does that leave us if indeed he is correct? — schopenhauer1

The only way I could imagine him being correct is if nobody can ever be happy, even for a moment. Since that would require that everybody that has ever said they are happy was lying, I find that too implausible to consider. It seems more likely that the Earth is made of cheese.

:smile: Yes it's amazing how destructive and disloyal to their country some politicians can be when trying to win power. We have that here at the moment. The opposition helped pass a bill, against the government's wishes, to allow seriously ill people in offshore immigration detention centres to come to Australia for treatment. The government, who claim the sole reason for their very harsh treatment of asylum seekers is to discourage people from setting out in boats from Indonesia to try to get here, is now blaring out to anybody who will listen that the passing of the bill has now made it easy for people-smugglers to get people into our country.

Firstly it's not true and secondly, even if it were, the last thing that should be done is advertise it to people smugglers.

All because they want to try to win a looming election by c;aiming to be 'tougher on illegal immigrants'.
:sad:

But what does this urge "feel" like? What does it spring from? — schopenhauer1

For what it feels like, you'd have to ask the people that are having children now. My youngest is aged nineteen, so I can't remember. For where it springs from, I'd say evolution. Species that don't have an inbuilt urge to procreate will be replaced by those that do.

But regardless of whether we can answer either of those questions, we can be sure that the urge is there as a powerful driver in many humans, enough so that it can never be practical to expect all humans to voluntarily resist it.

This was meant to be about bringing people together in the understanding that we can solve the problem of suffering. — schopenhauer1

It can't do that because nobody has that understanding. We all know that the urge to procreate is far too strong for a movement against it to ever be successful in persuading everybody to have no offspring.

So no matter how fervently an antinatalist might believe, and evangelise their message, that procreation is immoral, they will never succeed. New people will continue to be born as long as the world remains habitable by large numbers of humans, and those new people will encounter suffering (as well as joy and a whole host of other experiences).

In mathematics a statement that contains an equals sign can be an identity or an equation.

An identity holds true for all possible values of the pronumerals (variable names). An example is $\sin^2\theta + \cos^2\theta = 1$, which is true for any value of the pronumeral $\theta$.

An equation, when contrasted with an identity, is something that is to be solved in order to find a value for one of the pronumerals. If there is only one pronumeral, the solution will be a number. Otherwise it will be a formula that uses numbers and the other pronumerals. An example is $\sin x = 1$, or another one is wrote you wrote above, followed by the instruction 'solve for c'.

But it begs the quest "Why on earth would the Tories be trying to convince people that England was more violent than the USA?". Any ideas? — Sir2u

As the article and my post make quite clear, they used it to attack the then-government (Labour) in an attempt to make them lose the upcoming election - which they did, but not because of that issue.

And we all know how greatly things have improved since then don't we? — Sir2u

No I don't. I have no statistics and none have been produced in this thread that I have seen. So all I have to go on are impressions: I was in the UK a year ago and it seemed to me to be more peaceful and prosperous than it was when I was last there, in 2007.

If these do not seem real, you can verify the data through the sources they provide at the bottom of the page. — Sir2u

The figures may or may not be accurate. We don't know. But we do know that the sources are anything but impartial.

The two sources listed in the footnote of the 'we love guns!' site in the link are just news articles in the Daily Telegraph, a UK paper with links to the Tory party. Further, the articles report that the statistics were compiled by Tory MPs in order to help their attacks against the then-Labour government. The article claims the statistical sources from which the Tories compiled their figures were an EU statistical agency, but no reference is given to a specific source at that agency, or to any other source.

The articles also report that the Home Secretary of the time vigorously rejected the figures.

Finally, regardless of whether the figures are fair representations of the EU figures and those from other countries like USA (no source provided), or just made up for the sake of political point-scoring, are ten years old.

I am surprised at myself that I continue to be surprised that people believe controversial claims they read on heavily partisan websites, without bothering to follow the chain of references (if any) to see if they lead to anything other than just more partisan sources.

You wrote the following in response to my saying that your direct reply to my question about a ratio in the post to which I was responding was the first time you had directly addressed my question and mentioned 'ratio':

I am so sure that I had posted all of those things below.... — Sir2u

yet the only one of the 'things below' that mentioned 'ratio' was the one that I had already said was the first time you did it, and none of them related to the disputed claim about attendance at crime scenes.

Learn to read. — Sir2u

you do not understand English very well. — Sir2u

I took it for granted that you knew how to read. — Sir2u

Could you just remind me exactly what accusations you were making about attempted bullying?

My original statement stands until someone can prove it to be false. — Sir2u

As you know, that's not how things work on a philosophy forum. The onus is on the person making a claim to justify it.

Be careful using "that that" in sentences, S gets upset and pulls out his dictionary and some webpages about it. — Sir2u

In the instance to which you are referring, my use of 'that that ' was a mistake. I was careless when typing that sentence. I either didn't notice that I had typed the word twice, or I did but mixed it up with a sentence a few lines earlier where the doubling was used intentionally and correctly.

It appears that it is actually not at all painful to admit that one is wrong sometimes.

You asked about the ration and I explained several times that it is the number of cops to the number of guns that need to be collected or confiscated. — Sir2u

No you didn't. That is the first time you have proposed that as an answer to my question, or that you have even mentioned the word 'ratio' in your replies. Further, the ratio you mention in this quote is one of object counts (numbers of police and number of guns), not events (crimes and attendances at crimes) which is what your original claim that I dispute was about.

If you want to drop your original rhetorical flourish about police not preventing crime and instead focus on an argument about there being too few police to enforce a government gun acquisition program, by all means do so. There are complex issues to discuss in that direction. But saying that that your claim about police attending crime scenes was making that point falls flat.

It is not about beating and bullying others into submission and trying to force them into admitting that they are wrong. — Sir2u

I am sorry that you feel bullied. I am not aware of having written anything that was bullying, but if I have you need only point it out and I will delete it and apologise.

there was probably never any guns to get rid of — Sir2u

No. Read about the Australian gun buy-back here. There is plenty of room for a discussion about the differences between the pre-1996 Australian situation and the current US situation, and the effect those differences have on the viability of applying the same strategy to the US, but suggesting there were no guns to be confiscated forms no part of that. Approximately 650,000 guns were collected and destroyed.