Consistent Histories solipsism?

[Morbert]

You say solipsism is avoided in quasi classical domains.
Is that the macroscopic?

Quasiclassical domains are consistent sets describing hydrodynamic variables. The regular phenomena we experience belong to a quasiclassical domain, but quasiclassical does not mean macroscopic. There are macroscopic properties that are not quasiclassical.

 

[JamieSalaor]

So, would that mean that as there are non quasiclassicaly macroscopic properties then solipsism in CH is still implied?
Or would you still say Dowker and Kent are mistaken?

Basically, do you disagree with their charges of true solipsism?

 

[Morbert]

So, would that mean that as there are non quasiclassicaly macroscopic properties then solipsism in CH is still implied?
Or would you still say Dowker and Kent are mistaken?

Basically, do you disagree with their charges of true solipsism?

Unless I am missing something, Dowker and Kent don't charge CH itself with true solipsism. Could you highlight where they do?

 

[JamieSalaor]

They ultimately go on to argue that CH implies solipsism an I will get to that but I have so far only addressed their first charge, which is that since CH does not sharply define the notion of an "actual history" it accommodates all sorts of notions of an actual history, including solipsism of the moment. They see this as a negative point.

You note that they go on to imply solipsism.
Did you simply mean solipsism of the moment?

 

[Morbert]

You note that they go on to imply solipsism.
Did you simply mean solipsism of the moment?

They go on to argue that CH implies solipsism of the moment for reasons I addressed earlier, and solipsism if an "IGUS-centric" version of CH interpretation is adopted, but then remark that solipsism can be avoided if CH is interpreted in terms of quasiclassical domains. I don't believe it is necessary to appeal to quasiclassical domains to see off solipsism but they at least accept that CH does not necessarily imply solipsism.

 

[JamieSalaor]

Would you says an IGUS centric interpretation would be unreasonable?
Also, do you agree that if that position were taken CH would be solipsistic?
As they say in the paper that don't think solipsism is reasonable so I assume they do not think an IGUS centric will be... Thanks so much for all your input!

 

[Morbert]

Would you says an IGUS centric interpretation would be unreasonable?
Also, do you agree that if that position were taken CH would be solipsistic?
As they say in the paper that don't think solipsism is reasonable so I assume they do not think an IGUS centric will be...Thanks so much for all your input!

I think the IGUS-centric interpretation is a misunderstanding of CH, for the same reasons I mentioned previously (omission of a property from a set is not a declaration of non-existence). We can construct the IGUS sets Dowker and Kent talk about without committing ourselves to solipsism.

 

[JamieSalaor]

Seems then at the end of all this since even IGUS centric interpretations aren't committed to solipsism. There is absolutely no reason to say CH is solipsistic. Also, dowker and Kent made some unreasonable assessments of the CH interpretation, by attributing things like solipsism to it.

Would you agree with this?

I'm happy to conclude now if so you've basically cleared so much up
Thank you so much for everything!

 

[JamieSalaor]

Also would you say most consistent historians agree that CH does definitely not imply solipsism?

Thanks!

 

[AlexCaledin]

The most consistent historian is Robert Griffiths! He says in the very end of his book,
page 370,

To be sure, neither quantum nor classical mechanics provides watertight arguments in favor of an independent reality. In the final analysis, believing that there is a real world "out there", independent of ourselves, is a matter of faith. The point is that quantum mechanics is just as consistent with this faith as was classical mechanics.

Consistent Quantum Theory

 

[JamieSalaor]

Well yes, that's the thing with solipsism. You can always come up with an argument suggesting it. But nothing in science implies that it's the case. Therefore being a solipsist would be too be a matter of faith. One that seems considerably more unreasonable and just unnecessarily arrogant...

What I take from the quote is the Griffiths is saying that Consistent Histories suggests no reason at all to deny the existence of external reality... But if one were to deny external reality it would be very difficult to convince them otherwise...
Carlo Rovelli said the following about solipsism in an email conversation I had with him

Solipsism is a disease which plagues those who are too insecure to accept the limits of our knowledge

Thanks for everything everyone