No Socratic dialogue can undermine straightforward logic. — Michael

How do you know that the Idealist reality operates by "straight forward logic"?

Well, and the point isn't anything about logic anyway. It's about what it would take, based on what I've observed about Michael's personality, behavior, etc. (which is similar to many people I've interacted with online, over 2+ decades, in the course of hundreds and hundreds of conversations), for him to come to some understanding of the view.

I'm not at all of the opinion that people are all "ideal rational agents," without unique psychologies that have to be catered to . . . especially after they've demonstrated a number of times that they're not.

I certainly do not believe that I'm an "ideal reational agent," either. Things have to be explained in particular ways to me, with certain types of language, etc., for me to be able to understand them. Hence the huge problem I tend to have with contintental works.

How do you know that the Idealist reality operates by "straight forward logic"? — tom

How do we know that any kind of reality operates by logic? Does the question even make sense? It's language that operates by logic, and I see no reason to believe that the rules of semantic derivation depend on the ontological nature of things.

It doesn't matter if you're an idealist or not. The meaning of the sentences "only mental phenomena exists" and "only my mental phenomena exists" are such that the latter doesn't follow from the former, just as the meaning of the sentences "only physical bodies exist" and "only my physical body exists" are such that the latter doesn't follow from the former.

Haha re the idea of it being a matter of following from sentences.

If it's not a matter of following from sentences then it's not a matter of one claim ("idealism is true") logically entailing another ("solipsism is true").

What, exactly, do you think a valid argument involves? A concluding sentence that follows from premised sentences. If you want to claim that idealism entails solipsism then you have to argue that "idealism is true" entails "solipsism is true". If you can't do that then your claim fails. And given that "idealism is true" (or "only mental phenomena exists") doesn't entail "solipsism is true" (or "only my mental phenomena exists") your claim is false.

And haha re reading my comment as implying an objection to the idea of anything following from sentences in general.

How do we know that any kind of reality operates by logic? Does the question even make sense? It's language that operates by logic, and I see no reason to believe that the rules of semantic derivation depend on the ontological nature of things. — Michael

So, if Idealist reality does not operate by logic, then what rules does it follow?

I don't understand what you mean by reality operating (or not operating) by logic. It seems like a category error. If you just want to know if the axioms and rules of inference that we currently use when determining the relationship between semantic expressions depend on the world being more than just mental phenomena, the idealist would disagree. Logic is indifferent to ontology.

I'm just interested in what rules Idealist reality might follow and how we can discover them.

The exact same rules that we currently use. Why would it be any different? The laws of thought and the rules of inference do not depend on realism or physicalism or any other ontology being the case. Why would you think otherwise? And how do the proponents of realism or physicalism or any other ontology determine the proper relationship between statements? Again, logic is indifferent to ontology.

So it still remains the case that "only mental phenomena exists" does not entail "only my mental phenomena exists", and so idealism does not entail solipsism. The persistent claim that it does is simply false, and obviously so. Just as would be the claim that "only physical bodies exist" entails "only my physical body exists".

If only someone were claiming that the proposition "only mental phenomena exist" entailed the proposition "only my mental phenomena exist."

Given that you and Harry are saying that idealism logically entails solipsism, that's exactly what you're claiming.

The exact same rules that we currently use. — Michael

So, Idealist reality obeys the laws of physics. Thus Idealism and physicalism are identical except Idealism applies the label to everything in Reality "not objectively real"?

Under Idealism, how are these laws discovered?

So, Idealist reality obeys the laws of physics. Thus Idealism and physicalism are identical except Idealism applies the label to everything in Reality "not objectively real"?

Under Idealism, how are these laws discovered? — tom

Who said anything about the laws of physics? We were talking about logic; about what statements do or do not follow from others.

Who said anything about the laws of physics? We were talking about logic; about what statements do or do not follow from others. — Michael

Which has nothing to do with Idealism?

Anyway, I asked what rules Idealist reality follows, and you seemed to reply,

The exact same rules that we currently use. — Michael

Which, as far as I'm aware are the laws of physics. i.e. Reality obeys the laws of physics. So, how is idealism different from (Physicalism + Label)?

Which has nothing to do with Idealism? — tom

It has nothing to do with what I'm discussing, which is that idealism does not entail solipsism.

Anyway, I asked what rules Idealist reality follows, and you seemed to reply,

You asked "if Idealist reality does not operate by logic, then what rules does it follow?" and I replied by explaining that it's not clear what you mean by reality operating by logic, and then clarifying that language under an idealist ontology will operate according to the logic with which we're already familiar (given that, according to the idealist, idealism is the case, and language does operate according to familiar logic).

Which, as far as I'm aware are the laws of physics. i.e. Reality obeys the laws of physics. So, how is idealism different from (Physicalism + Label)?

Again, I was referring to logical rules.

Logic is the same whether idealism or not-idealism is the case. And just as in either case "only physical bodies exist" does not entail "only my physical body exists", "only mental phenomena exists" does not entail "only my mental phenomena exists".

So unless you want to show that "only mental phenomena exists" entails "only my mental phenomena exists", I don't think whatever you're trying to say has any relevance to what I'm saying.

Logic is the same whether idealism or not-idealism is the case. — Michael

How do you know? How do you know that logic is independent of the rules that govern reality. For example, imagine a logical operator that might exist under certain rules of reality, but not others. What about a logic that is able to construct proofs that require infinite steps or, the square root of"not".

Why don't proofs with an infinite number of steps work under idealism, or the square root of "not" allowed as a logical operator?

Why don't proofs with an infinite number of steps work under idealism, or the square root of "not" allowed as a logical operator? — tom

Because, according to the idealist, these proofs don't work, such a square root isn't allowed, and idealism is the case.

How would the non-idealist address the same question (albeit "under not-idealism")?

Given that you and Harry are saying that idealism logically entails solipsism, that's exactly what you're claiming. — Michael

Gee, it's surprising that you'd believe that you know what I'm claiming better than I do.

</facetiousness>

Gee, it's surprising that you'd believe that you know what I'm claiming better than I do. — Terrapin Station

Here you said "What I'm saying is that solipsism is logically entailed by [idealism], and idealists are believing something incoherent if they're not solipsists.".

Are you claiming that idealism is a sentence?

I'm claiming that "Logical consequence is one of the most fundamental concepts in logic. It is the relationship between statements that holds true when one logically 'follows from' one or more others. ... The philosophical analysis of logical consequence involves asking, 'in what sense does a conclusion follow from its premises?' and 'what does it mean for a conclusion to be a consequence of premises?'".

So when you say that idealism logically entails solipsism you're saying that the statement "idealism is the case" logically entails the statement "solipsism is the case".

"Are you claiming that idealism is a sentence" is a yes or no question. Try typing less in response to a yes or no question.

It's a misleading question that tries to avoid addressing the point I'm making. I'm not going to fall for such a transparent attempt. The fact of the matter is that if the sentence "only my mental phenomena exists" does not follow from the sentence "only mental phenomena exists" then idealism does not logically entail solipsism. Your persistent denial and unwillingness to face up to this is both obvious and time wasting. Par for the course, really.

It's just a question. It's not leading anywhere. Yes or no, are you saying that idealism is a sentence/statement?

In my opinion, one is not capable of having a conversation if one is not capable of answering a simple yes/no question. You'd certainly not be capable/qualified to do anything more complicated if you can't handle that.

I like how everything devolves into a meta-discussion when you're involved, by the way.

Given your unwillingness to either provide an argument that shows that idealism entails solipsism or to address the fact that logic and logical consequence is a concern of statements, why should I put in the effort to answer your questions? I've shown you why idealism doesn't entail solipsism so the ball is in your court to show me why it does. Else, again, I have no reasons to accept your bare assertion.

Because, according to the idealist, these proofs don't work, such a square root isn't allowed, and idealism is the case.

How would the non-idealist address the same question? — Michael

Under physicalism, the square root of NOT is allowed, which is a good thing, since that particular logical operator exists in REALITY.

Given your inability or bad-attitude approach--whichever it is--to answer a simple yes or no question, why should I expend the time and effort to do anything more complex with you? You're not capable of the most simple conversational interaction.

Under physicalism, the square root of NOT is allowed, which is a good thing, since that particular logical operator exists in REALITY. — tom

What exactly do you mean by the square root of NOT? I thought you were talking about the square root of the word "not", which doesn't make sense to me. Whatever it is, is it to do with logic or physics? If the latter then, again, it's irrelevant to what I'm talking about, which is logic. And specifically in this case the logic which shows that "only mental phenomena exists" does not logically entail "only my mental phenomena exists" (i.e. the logic of natural language).

So, again, unless you can show that "only mental phenomena exists" logically entails "only my mental phenomena exists" then whatever it is you're talking about is irrelevant to what I'm saying.