The only thing that matters to this discussion is the truth or falsity of the proposition "knowledge of other minds is impossible". — Michael

To me the issue is just as much about an 'external' world.

ES says : It's wrong to assume there is something we can be wrong about.

We can make claims about things that don't exist. p → q is true even if p is false. — Michael

The point is that it's a claim about norms, about constraints on possible rational agents. It's a thesis about the world, that it contains such norms.

Maths and logic are something "other" than the subject, but I don't think it right to think of them as being "external" (in the sense that the material world is said to be external). — Michael

But it starts to get a bit silly, for now we have a subject who 'is' all of mathematics, and the epistemological solipsist is therefore only making normative (?) claims about him which are himself ?

In case it helps, I don't think 'material' is easy to cash. I intentionally generalize 'external' to 'something I can be wrong about' to minimize my presuppositions and maximize the generality of my conclusions.

Consider the thread's theme, our minimal epistemic commitment. We can argue endlessly about the nature of the 'space' we share, about the meaning of 'material' and 'mental,' but it doesn't make sense to say we can't be right or wrong, for that is to say that it's wrong to think we can be wrong.

For me the issue is that the claimant wants to bind or makes a normative claim on all possible rational agents, the rational agent as such. This claim seems to transcend the claimant, seems to be aimed beyond his experience.

and if there are other minds then these other minds cannot know that there are other minds. — Michael

Normative of psychological claim ? And isn't this a claim about something beyond him ? The world is such that, if there are other rational minds, then those minds will have a nature such that ....(or be bound to rational norms such that ...)

The "external world" as you mean here isn't what the solipsist (or idealist) means. — Michael

How do you take external ? We don't want to be too specific, in my view. One need not have a settled metaphysical view on the nature of our world (that it's really X or actually Y).

It just claims that knowledge of other minds is impossible. — Michael

So it claims that I can't know there are other minds ?

I haven't said that the external world is the work of our organs; what on Earth made you think that? :roll: — Janus

The part where you said (implied) that ? The part that I quoted?

it's simple phenomenology. — Janus

That's not always a good thing !

I don't deny that sense organs are affected, ... But that whole story is abstracted from the more primordial experience of being in the world ... a world of images, sounds and bodily sensations. — Janus

Incoherent, however initially plausible...to those like us exposed to the tradition, anyway.

And others say even that the external world is the work of our organs? But then our body, as a part of this external world, would be the work of our organs! But then our organs themselves would be the work of our organs! ... Consequently, the external world is NOT the work of our organs—?

https://gutenberg.org/files/4363/4363-h/4363-h.html

.

The solipsist can argue as if there are other minds, and still claim that he doesn't know that there are other minds. — Michael

The problem is when the solipsist tells me that I can't know there's a world beyond me.

I think we are neglecting the 'external world' theme, which I see as just important.

ES claims that it's irrational to assume that one can be irrational, wrong to assume there's something one can be wrong about (an 'external world' as a target of claims.)

The epistemological solipsist says that one cannot know that there are other minds, — Michael

Who is this one ? Is this not the issue ? Is he saying that he cannot know ? Or that it's the nature (psychological) of other minds that they can't know ? Or that it's irrational or unjustified (normative rationality) for such an other mind to claim to know ?

Given the context, I think the last option makes most sense. But both of the last two seem problematic, with the first being irrelevant.

I've said that our lives, phenomenologically speaking, consists in images. — Janus

Yes. You keep making claims about the private minds of others, which should not be possible, unless the entities in those minds are part of the usual explanatory nexus.

But day to day, we do not experience stable objects; we experience a flux of imagery. — Janus

So you claim, but this is metaphysical theory, which could only be defended or justified in terms of universal rational norms.

We know that it is the more primordial experience of imagery that makes this co-creation possible. — Janus

As I see it, we don't know this: you merely think it. In fact, I've been arguing that this ghost story was developed in the first place by taking a genuine, shared, 'external' world for granted, one in which sense-organs are affected by objects. With Hume and Kant, this idea was pushed to absurdity, till the sense organs were ridiculously the product of (the sensations of) the sense organs.

So then, why do you keep asking "where is the territory ?" — Olivier5

Because you haven't explicitly adopted my suggested understanding of it, I was trying to figure out yours. How do you cash out 'representation' ?

But of course in order to understand that the map is not the territory, one must have access to both the map and the territory. — Banno

:up:

Or (to save the metaphor) we can let the territory be all that is the case and the map be what we are warrant to claim is the case (our set of rationally settled beliefs.)

The new one is heinous though. — GLEN willows

Agreed!

But the first one, the first time seeing it in the theater,...

And do you agree Descartes never really disprove the BIAV? Except by bringing God in. — GLEN willows

I think there are two issues here that are getting entangled. One issue is logical/grammatical. This is what I've been focusing on.

The second involves probability and intensities of certainty. You and I might agree that it's logically possible that we are both brains in a vat, and we might discuss things until we give up on trying to prove otherwise. Fair enough. But our claims refer to an external world. It is or is not the case that we are really in a vat. But the 'structure' of rational discussion puts us in the same world together, whatever its nature, both conforming to norms for concept and inference application to understand and persuade one another.

Does that help ? I'm not trying to prove I'm not in a vat. I'm also not trying to prove I'm an alien raised as a human who was never told of his powers. Because I don't suspect such things. But both are coherent. Maybe the year is 3095. I was in a car accident and my brain was preserved. Some genuine Vanilla Sky stuff! (Note though our shared concept of some real world in contrast to the illusion that keeps this wild stuff coherent. We must have contrast, something that is the case.)

https://duckduckgo.com/?t=ffab&q=vanilla+sky&iax=videos&ia=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D7Zk4y9ZRlwA

Frankly I'm still surprised that people can't even IMAGINE that we could be brains in vats - which Descartes attempted to disprove but didn't ....or on future virtual reality ventures...or extended dream states. — GLEN willows

I can easily imagine vats. I've seen The Matrix and lots of other sci fi (like the happy world of the 'dead' in Black Mirror). Trust me, sir. That's not the issue.

Can we put can the conclusion "we know there are other minds" into a formal logic equation?

Premise
Premise
Conclusion? — GLEN willows

You might want to look at this thread : https://thephilosophyforum.com/discussion/13308/our-minimal-epistemic-commitment-fixing-descartes-cogito

As @180 Proof has seen, the central issue is 'normative rationality.' It's possible/thinkable that I really am the last creature in the universe able to make excuses, so the contingent existence of others is not crucial here.

The point is that ES aims at a world beyond itself, describing norms that bind even merely possible rational agents. The existence of other minds and the external world is not necessarily rejected but one can not be sure of its existence. Granted that all the others might be dead, and assuming you are not satisfied with my 'possible' or 'potential' rational agents, you can still see, I hope, that an external world is being referenced in terms of norms that transcend the claimant. One cannot be sure. It's not just that I am not in fact sure. No. It's wrong or irrational for you and anyone 'out there' to think you can be sure...that there is an out there in the first place. In other words, 'one ought not take the possibility of norms for granted.' 'It might be wrong to think there is something we might be wrong about.'

ven if I'm the last (or first) man alive, the various axioms and rules of inference hold. The law of noncontradiction doesn't just fade away in a nuclear holocaust where I'm the only survivor. — Michael

I think this leans on psychologism, as if logic were mere facts about human cognition and not normative, a thesis that can only be established if it is false.

We've found where the boot pinches. The essence of my position is that rationality is normative, implicitly about a world beyond the philosopher. "One (in general, as a rational agent) ought not to assume that there is a world one can be wrong about...or a world beyond one to which norms apply."

I can be right or wrong about the world all by myself, thank you very much. — Mww

I don't dispute that rational agents can make true or false claims. Much of what we do (so runs the theory) is keep score on the noninferential claims and inferences of others. But I don't think the notion of a private language makes sense, so you are running pirated software, sir. Do we not bark and hiss in these inherited norm-governed, sound patterns known as English ?

even (your) reliance on logic – normative rationality – presupposes selves-other-than-yourself (i.e. discursive community) — 180 Proof

:up:

I can talk about things that don't exist. Even if atheism is true I can talk about God, and if I claim that God exists then my claim is false. — Michael

Yes, granted. That's not the issue.

I don't know why you think it would be a fantasy. Experiences are real, not made up. — Michael

I refer just to the usual, practical distinction of what seemed to be the case and what is the case. 'I thought I paid the rent, but that was just a dream.'

I don't see what grip we can give 'real' or 'experience' is there is just one blob of world-truth-experience-dream-reality-self. I can of course imagine a sole survivor. So the issue is the status of rationality, whether it makes sense for an inside without an outside to proclaim and justify norms.

the claim that just one mind exists (or that only one mind can be known to exist) is coherent, contrary to your objection. — Michael

I guess I'll grant you this edge case (that there can be a last rational agent in the universe), but this is a mere crumb.

My primary point is that epistemological solipsism is incoherent as a claim about other minds in general, namely that they ought not just assume that such other minds exist.

I take this as a claim about the norms that apply to all rational agents, a claim about a world that transcends the claimant, one he could be wrong about. 'One ought not assume that there are others.'

Or, put it this way, 'one ought not assume there are norms.' Do norms make sense without a world in the most general sense to govern, potential/general agents to which they apply ?

As Pie pointed out, no one can logically prove there are other minds. — GLEN willows

Actually, it's almost the reverse. Logic and rationality are ego-transcending. That's how we use them and why we value them. An insane person can fear that others are p-zombies or the figments of dreams, but for a philosopher to claim that no one can be is to make a claim about the very others who might not exist.

Here's another version of ES : Rational agents ought not assume there are other rational agents.

Is this not problematic?

You aren't quite understanding me. Perpend. "In epistemology, epistemological solipsism is the claim that one can only be sure of the existence of one's mind. The existence of other minds and the external world is not necessarily rejected but one can not be sure of its existence. ...Epistemological solipsists claim that realism begs the question: assuming there is a universe that is independent of the agent's mind, the agent can only ever know of this universe through the agent's senses. "

I take this claim to be philosophical, which is to say that, because it is (purportedly ) justified by a universal reason binding all rational agents, it itself would be binding likewise (if actually so justified and coherent). If a mathematician proves, for instance, that $\pi ^ \pi$ is irrational, other mathematicians are bound to acknowledge what has now become a fact about the real number system. Note that conclusions about the real number system are implicitly also about what mathematicians ought to believe. So statements about numbers are easily translated into statements about norms.

I will now translate epistemological solipsism into a form that reveals the incoherence.

"The epistemological solipsist claims that it's wrong for a philosopher to simply assume that there's something a philosopher can be wrong about." I use "something one can be wrong about" instead of "external world" because I think it captures the most general notion of inside/outside. It does not make sense for a self without a world or others to be able to be wrong (unless one maybe 'cheats' and gives the self an unconscious, playing the same role as that which he could be wrong about, in a failure of self-knowledge that assumes two objects after all.)

Anyway, the problem is that this statement itself makes claims about all rational agents, assuming the very thing it declares in the same breath to be unjustified.

There is nothing interesting in that pedantic world of facts except the science and math it makes possible. For me there is nothing interesting in chasing your tail trying to establish how our propositions are to be justified; because they can never be justified by the rich streams of imagery which constitute our actual lives. So, for me the best course for those who love science and math is to "shut up and calculate" and enjoy the richness and artistry of math and science (which logic totally lacks). — Janus

Note that your perspective (on its face is radically 'for you.') The implication's are highly impractical. Why go to the doctor to get a bone set and drink bleach or eat asparagus ? It's as if you don't think inferences are central even to practical life.

This also seems problematic:

There is nothing interesting in ... trying to establish how our propositions are to be justified; because they can never be justified by the rich streams of imagery which constitute our actual lives.

You seem to be justifying the unimportance of establishing how justification how works by declaring it to be impossible in terms of an authority that's uncheckable even in principle. You also refer to our lives, without it being clear how a ghost trapped in its own private imagery could make trustworthy claims about other ghosts...if trustworthy makes any sense is this world of dreams without contrast.

Our whole lives consist in streams of imagery, a unique stream to each person. From out of those concrete streams we abstract the fictive things which remain timelessly the same, which make up the world of familiar objects, about only which is it possible to derive a world of facts, a world consisting totally of facts, a world that is the totality of facts. But this world is never experienced; it is a lifeless attenuated world of the mind. — Janus

Hi. I'm aware of that theory. I sketch it in my thread.

On this view, hairdryers and toothpicks are just handy ways to organize sensations...and electrons and quarks are just handy ways to organize hairdryers and toothpicks. I seem to see other people, but I can't be sure, because what I mean by person is roughly what I mean by 'I,' this existence I know 'directly.' My states of mind, my thoughts and sensations, are phosphorescently present for me, infinitely intimate. I can no more be wrong about what I mean by a word or how I see a patch of color than 2 + 2 can equal 5. And so on. I extend the same courtesy to you out there, behind the mask of your face and its smiles and grimaces, just in case you exist back there.

I criticize it elsewhere like this, following Ryle and Nietzsche.

I think there's a POV trick to be sussed out here. We see others from the outside and ourselves from the inside. So it's plausible that individuals depend on their sense organs and brain as mediators for them of their environment. But if we try to build only from the inside, we talk nonsense. We call everything sense-data while ( pretending to be ) no longer taking the sense organs and objects affecting them in the 'outside' or 'public' world for granted. The stereoscopic key may be remembering that the entities populating the 'inner' and 'outer' worlds are part of the same causal/explanatory nexus.

I think Sellars makes a good case the the 'seems' operator (from which we get imagery, raw feels, ec.) is semantically parasitic on assertions. So 'the light looks red' depends on 'the light is red' for its significance, playing an adjusted but similar role in the inferences we'll tolerate from one another and use to explain ourselves and others.

n my mind, the idea implies that smaller is just a different scale than larger, not a more 'fundamental' level. — Olivier5

:up:

Go where? — Olivier5

Noumena. Of course people still debate the best interpretation, and I understand why the concept was tempting (as the territory), but I suspect the the true/warranted distinction does the same work with less confusion.

The OP is confused. There is no peace in death. There is nothing. What the OP wants is peace in life. — Philosophim

What you say has merit, but consider this edge case :

A man will be tortured for hours for information he does not have. He will then be killed. Is it reasonable for him to grab at a means to end his consciousness, if he knows all this with certainty ?

Or consider, more typically, a person aware that they are sinking into dementia...Are there states worse than death ? So that death is to be sought ? My position is yes.

Are you talking of the thing in itself? — Olivier5

Yes, I had that in mind as a possible answer, except I think Kant was wrong to go there.

Solipsism isn't a self without a world. It's that the world is the Self. — Tate

Six of one, half a dozen of the other. Does it make sense for worldself to be wrong about a worldself ?

Let's say you go Freudian and give this blob an unconscious...then you are creating something it can be right or wrong about, something it knows indirectly. A (second, breakaway )world for the world to guess about.

Consider also that my primary target is epistemological solipsism, so this is a bit of tangent (not without its fun, to be sure.)

Matter has no “bottom”, no “foundation”. It’s turtles all the way down. — Olivier5

I like this idea, by the way. We could keep finding tinier, more and more quasifundamental things.

Why would there be a bottom layer? — Olivier5

Personally I don't think there needs to be one, nor must we even think of stacked layers. But where then is the territory ? Is it maps all the way down ? If so, does not the metaphor fail or become misleading ?

I currently prefer to say that there are electrons and promises and itches and noses...all of them caught up in the same causal nexus. I willing to revise beliefs about these things and their relationships.

Scientific knowledge, in this view, would be sets of beliefs about such entities that were established as warranted through objective, critical discussions and experiments. The hope of course is that they are true, but it seems the most we can manage is to make sure they are warranted.

Which is your point, that solipsists are inappropriately searching for certainty? Or that solipsism is incoherent due to a lack of "real" social interaction? — Tate

The epistemological solipsist is making a claims about norms that transcend him, about what any rational person ought to assume or not, about a world beyond him.

(It's also seemingly incoherent for a self without a world (typically with others) to be able to be right or wrong in the first place. What can that even mean ?)

So what is the territory made of ? Is there a deepest layer ?

I'm not trying to be difficult. I genuinely don't think we can cash the check of 'territory' very easily here. What do electrons and fields represent ? Keep in mind that I'm skeptical about the representation metaphor, so I'm just challenging it, seeing if it can be defended.

If there's a claim, there's a claimant. Any psychological position you take, whether it's transcending society, transcending time, transcending Everything, it's all the self. You never get beyond it. — Tate

What's that ? I can't hear you. And if I could, ....

Do you see how your reasoning aims beyond yourself towards me, attempting to bind me ?

"It's impossible for us to get beyond the self." The statement does what it says can't be done in the very saying of it.

As Witt said, Everything is circumscribed by the subject. — Tate

Respectfully, that's just about antithetical to the way I understand Wittgenstein.

part of the world that science deals with. — Olivier5

That doesn't exclude much. I count the social sciences, etc.