[tsimionescu]

> Why would we ask that? Not ideal for what? It just is.

I'm pretty sure GP was using "ideal" in the sense of "made up of ideas", as in the philosophical concept of idealism, which is essentially the opposite of materialism: idealism is the position that the real world is that of the mind, and physics and the physical world is an emergent property of our minds, not the other way around.

Not that I think this is a real coherent position worth discussing.

[skissane]

> Not that I think this is a real coherent position worth discussing.

Why is it not a "real coherent position worth discussing"?

[tsimionescu]

Because to me it seems that if it were made consistent, it would extend into solipsism. And if it does, I don't think it's worth discussing then.

[hnfong]

“the universe is the extension of the self” is precisely the idea we are talking about.

IMHO it is the only thing worth discussing.

And yes you can derive new “physics” with this idea alone.

[skissane]

> “the universe is the extension of the self” is precisely the idea we are talking about.

Idealists can take several possible approaches to the issue of how many people/minds exist:

1) Solipsism: only I exist, and everyone else is a figment of my imagination

2) Many minds: only minds ultimately exist, but many distinct minds exist (George Berkeley, John McTaggart)

3) Open individualism: I exist and everyone else exists too, but we are all ultimately the same person, and the idea that we are different people is an illusion (not necessarily an idealist view, but one open to an idealist to adopt; most famous notable proponent is Daniel Kolak; but Kolak in the introduction of his book I Am You extensively quotes the physicists Freeman Dyson and Erwin Schrödinger as expressing the same view)

4) Pan(en)theism: only one mind/person ultimately exists, but we are somehow "sub-minds"/"sub-persons" of that ultimate person. One might call that single ultimate person "God", albeit it is defining the term "God" in a very different way than classical Western theism does. Or, maybe we could call it the "Universe", or borrow Plato's term "the World Soul". (Maybe there is not much difference between (3) and (4), but (4) would view the distinction between different "sub-minds"/"sub-persons" as more "real" than (3) does.)

5) Panpsychism: everything in the universe (even individual atoms) is conscious, and hence has a distinct mind. This in a sense is a variant of (2), but proposes far more minds than Berkeley or McTaggart would ever have admitted. Not all panpsychists are idealists, but you can certainly be an idealist panpsychist

Critics of idealism tend to focus on (1), but in practice (1) has never had any serious proponents. All serious idealists have espoused (2)-(5) (or maybe some other variation I've missed)

See also the philosopher David Chalmers' paper in which he proposes his own taxonomy of idealisms, different from mine: https://philpapers.org/archive/CHAIAT-11.pdf

As an idealist, my starting position is (2), although I have some sympathy for (4).

> And yes you can derive new “physics” with this idea alone.

I don't know exactly what you mean, but I'm not a fan of that kind of talk.

We have to distinguish between physics the natural science, and the philosophical discipline of the philosophy of physics, which is a sub-discipline of the philosophy of science

The idealism debate fundamentally belongs to metaphysics (although contemporary presentations often focus on it through the lens of philosophy of mind instead), but it has obvious consequences for other philosophical disciplines, including epistemology, philosophy of mind, philosophy of science, and indeed philosophy of physics

But while adopting idealism must lead us to a different philosophy of physics, the actual content of physics the natural science is unchanged. Physics the natural science is ultimately just a bunch of mathematical tools for predicting future observations. Those tools, and how you use them, are exactly the same whether you are a materialist, an idealist, a dualist, or none of the above. The only difference is your answer to the philosophical debates about what those tools ultimately are, or what they ultimately mean.

[hnfong]

I'll admit I'm not too prepared to explicitly state what I meant by the line, but I'd personally take a more nuanced approach than "Those tools, and how you use them, are exactly the same whether you are a materialist, an idealist, a dualist, or none of the above".

I'll say that under standard laboratory conditions they should probably be the same most of the time. I hope you'll agree with me that *assuming* there are divergent predictions made by the "mind-first" approaches, they should be studied together with physics. Otherwise physics would become a study of idealized systems, much like insisting on Newtonian maths when the principles of relativity and quantum mechanics were discovered.

[skissane]

> I'll say that under standard laboratory conditions they should probably be the same most of the time. I hope you'll agree with me that assuming there are divergent predictions made by the "mind-first" approaches, they should be studied together with physics.

Can you give me an example of how a "mind-first" approach might give a divergent prediction, as to the outcome of a practically feasible experiment or observation? Maybe some versions of idealism might produce divergent predictions, but I don't believe divergent predictions are necessary to idealism, and many versions of idealism intentionally eschew divergent predictions.

> Otherwise physics would become a study of idealized systems, much like insisting on Newtonian maths when the principles of relativity and quantum mechanics were discovered.

Physics is a system for predicting future observations given past observations. Relativity and QM won because they generated more accurate future predictions than their predecessors.

But what, ultimately, is it that we are observing? Do the theoretical constructs proposed by physics (particles, waves, fields, forces, strings, branes, etc) "really" exist, or are they just abstract conceptual tools for accurate prediction generation? What does "really" even mean in that question? These are all philosophical questions, and idealism is one family of possible answers to (some of those) philosophical questions–but I don't see how that makes any difference to the whole business of generating accurate predictions of future observations–which is all that physics proper actually is, has ever been, or ever will be.

[tsimionescu]

1, solipsism, has the advantage that there is a solid argument to be made for it - I only have direct access to my own mind. That is why I am calling it coherent.

The other flavors don't have this advantage at all. It is impossible to trust my senses to arrive at the conclusion that other minds exist without first trusting them that they are correlated with features of a non-mind physical world. So, you can't use sense-based observations to claim that the world is made up of many minds.

Even in something like Hinduism, which could be called a form of idealism at a large stretch, the physical world exists as a shared mirage that our minds are made to experience, maya, but the true world is still a single thing, Brahman. And their claim is that this can be directly experienced by you through self reflection - so if we call it idealism, it's still a form of solipsism ultimately, albeit more interesting than I would normally give this credit for.

[skissane]

> 1, solipsism, has the advantage that there is a solid argument to be made for it - I only have direct access to my own mind. That is why I am calling it coherent.

In saying that, you are assuming certain standards for judging whether an argument is "solid". How do you justify those standards? Many would answer that they are axiomatic. But, if our standards for judging arguments are ultimately axiomatic, why can't the existence of other minds be axiomatic too?

By Münchhausen's trilemma, all arguments are ultimately reducible either to circularity, infinite regress, or dogma. Choose your poison, but I think dogma is least the poisonous of the three. I suppose that's another one of my axioms.

Of course, argument by axiom is sometimes very non-convincing – it can be used to defend any position whatsoever. However, most would agree that there is a big difference between defending as an axiom "1+1=2", versus papal infallibility, or the uncreatedness of the Quran, or whatever. The question is, is the axiom "other minds exist" more like the former kind of axiom or more like the latter? Surely, more like the former.

> The other flavors don't have this advantage at all. It is impossible to trust my senses to arrive at the conclusion that other minds exist without first trusting them that they are correlated with features of a non-mind physical world. So, you can't use sense-based observations to claim that the world is made up of many minds.

You can't use sense-based observations to make metaphysical claims–and materialism is just as much a metaphysical claim as idealism or dualism are. There is no possible experiment or observation that could distinguish materialism from idealism, and any possible sense data is equally explainable under other theory.

> And their claim is that this can be directly experienced by you through self reflection - so if we call it idealism, it's still a form of solipsism ultimately, albeit more interesting than I would normally give this credit for.

That Hindu position is arguably closer to my options (3) (open individualism) or (4) (pan(en)theism) than to classical solipsism (my option 1).

In classical solipsism, my mind is truly real, but yours isn't. In the Upanishads, both our minds are equally real (as Brahman), and equally unreal (as maya and karma); in their equal reality they are identical to each other, in their equal unreality they are distinct

[skissane]

What is inconsistent about non-solipsistic idealism?

[jemmyw]

Thanks that was insightful