Panpsychism: credible or not?

[Bohm2]

Now the panpsychist comes along are tries to tell me that not only does it appear in brains, but that it is s feature not only of the elements that comprise the grey matter, but also in every other type of element, energy, and in fact the whole universe in which it "features" (whatever that means).

This is how one panpsychist (Itay Shani) explains it:

However, it then becomes obligatory to ask why it is that when we look at our familiar world of middle-sized objects we find that some systems (e.g., humans, dogs, guinea pigs) exemplify unified macro-level subjectivity while others (e.g., rocks, tables, bronze statues) give the impression that they lack subjectivity altogether, and can be safely assumed to be devoid of a unified subjectivity matching the scale of their macro-level physical constitution...

The idea is that somewhere along the line which leads from the most elementary micro-level entities to familiar macro-level entities there appears an ontological bifurcation between (a) esonectic systems, which are constituted in such a manner that their micro-components are intensely interconnected, with the result being that the respective endo-phenomenological reservoirs of these micro-components join together in a coherent fashion, giving rise to a unified experiential domain; and (b) exonectic systems, whose constitution is such that their micro-components are held together in an orderly arrangement due to molecular bonding relations but which nevertheless lack interconnectedness of the sort which yields an integrated experiential domain and, as a result, are such that the interiors of their micro-components remain mutually separated – each arrested in its own cell, as it were. Brain-endowed biological creatures are the most obvious candidates for serving as examples of esonectic systems, while crystals are in good standing for serving as paradigmatic examples of exonectic systems.

[ReasonMadeFlesh]

I am very sad at how this thread continues to thrive - perhaps irrationally. My finite mind should have to keep up with it. Is any progress being made?

[Bohm2]

I am very sad at how this thread continues to thrive - perhaps irrationally. My finite mind should have to keep up with it. Is any progress being made?

There is little progress with philosophical questions. If you want progress you need to study science.

[Sim Al-Adim]

Well, then on a scientific slant: try this out.

Pan psychism vs. the Animal Kingdom.

Humans - have consciousness


Mammals - have consciousness


Reptiles - have consciousness


Jelly fish - have no central nervous system, but behave intentionally - implying they are aware of their "selves". Ie. they have consciousness.


Insects - behave as though conscious


Bacteria - do not seem to behave as though conscious. Certainly "responsive" to environmental signals. But not conscious in any apparent way.


Virus - the consensus among biologists is that the virus is "not alive". It cannot replicate its own DNA and when it high jacks the ribosomal subunits of its host, the viral machinery parts assemble in a statistical manner - a chaotic chance agreement among tiny little "things" manufactured-by-design long ago in some primordial soup. "Conscious"? I dare say "no". But is "a virus" an instrinsic process of a physical process that is demonstrative of what higher consciousness appears to be? I say, "yes". The making of a virus is a process that is integral to the making of a entity that is properly conscious.


So, I say consciousness is emergent and pan-psychism is a projection of consciousness onto non-conscious systems.

[Atreyu]

There have been some good arguments against panpsychism here, but they miss a key point. Namely, they fail to take into account that the property we are considering in this case is a property possessed by the entity (matter) in question and not by the perceiver himself.

"Redness", "yellowness", "hardness", and "softness" are properties which always "emerge" because they are properties asserted by the perceiver. This means that we cannot really assert that they are properties solely of the objects themselves, they are more properly properties of how the perceiver perceives them. What we call "hard" another entity might call "soft", and what we say is an emergent property of 'redness' might be perceived as an emergent property of 'yellowness' to a different perceiving entity. Properties which we (the perceiver) assert exists in matter, any matter, is always "emergent" because "emergent" in this case merely means that there comes a time when we can perceive such an attribute as matter grows in size and complexity.

But that is not at all what we are talking about in this particular case. Here, we are talking about an attribute possessed by the matter under consideration, not about an attribute which we the perceiver can perceive in it -- not a property which we assert exists in the matter. We are talking about a property that only exists from the point of view of the matter itself.

So the properties of "yellowness", "redness", "hardness", or "softness" never really do "emerge" in the sense that a property like awareness would "emerge". The former properties only "emerge" when an outside entity claims they exist, but the latter property could "emerge" and no one except the entity under consideration would know about it. So "hardness" seems to "emerge" because we become aware of it, and so does awareness itself. We say a hunk of matter "becomes" aware once we can ascertain it, but this tells us nothing of the subjective experience of the matter itself, and so it sheds no light on the issue. Does a virus have any awareness? No one knows. But if a virus became a cell (not that this is possible, but for the sake of discussion), all of us would now say that "life" or "awareness" has now "emerged" as a new property. But this means nothing if we do not have any idea (and we don't) if the virus already possessed some simple awareness that we merely could not detect.

So the flaw in these kinds of arguments is that they fail to see the inherent and crucial difference between properties which are asserted by another entity (so called "objective" properties like "hardness" and "softness") and properties which can only be asserted by the entity itself (so called "subjective" properties like "awareness", "consciousness", "thought", "feeling", etc). The difference is fundamental and what applies to the one may not apply to the other at all.

[Consul]

Panpsychism is a dead end from the scientific perspective.

Yes, you already said that, and (as far as I can see or understand) you are correct to say so. But you have not answered, or even acknowledged, the question Sy Borg asked: "So the untestable is not worth considering as a possibility?"

Does panpsychism make any sense as a real (natural/physical) possibility? Is a world where it is true coherently imaginable and intelligible?
You can certainly think or say e.g. "Tennis balls are conscious beings" without contradicting yourself logically; but if you do, it is not clear that you really understand what you are thinking or saying. What can make a tennis ball conscious? How can a tennis ball become and be conscious? What kind of (conscious) minds do tennis balls have?

[Consul]

QUOTE>
"Is panpsychism an intelligible doctrine?

Some contemporary philosophers who have given more thought to the conditions of meaningful discourse than was customary in previous times are inclined to dismiss panpsychism not as false or unproven but as unintelligible. Thus, in his Philosophical Investigations Ludwig Wittgenstein raises the question “Could one imagine a stone’s having consciousness?” and comments that if anyone can imagine this, it would merely amount to “image-mongery” (Sec. 390, p. 119 e). Such image-mongery, Wittgenstein seems to imply, would not show at all that in attributing consciousness to a stone one is making an intelligible statement. It would probably be pointless to try to “prove” that panpsychism is a meaningless doctrine. Any such attempt is liable to involve one in an elaborate and inconclusive defense of some controversial meaning criterion. However, it may be of some interest to explain more fully, without intending to settle anything, why not a few contemporary philosophers would maintain that the panpsychists do not succeed in asserting any new facts and in the end merely urge certain pictures on us.

To this end let us first consider the following imaginary disputes about the “inner” nature of a tennis ball. A holds the common view that the ball is made of rubber and not of living tissue, while B holds the unusual opinion that if we were to examine the inside of the tennis ball under a powerful microscope we would find a brain, a nervous system, and other physiological structures usually associated with consciousness. Furthermore, B maintains that if we listened very attentively to what goes on while tennis balls are in their can we would hear one ball whispering to the other, “My brother, be careful—don’t let them hit you too hard; if you roll into a bush on the other side of the fence you may spend the rest of your days in blissful peace.” There is genuine empirical disagreement between A and B and, as far as we know, A would be right if the ball or balls in question are of the familiar kind. Let us next suppose that C, after reading Paulsen and Waddington, becomes converted to panpsychism and starts saying such things as “the tennis ball is not a mere body—it has an inner psychic life, it is moved by love and hate, although not love and hate quite as we know them in human beings.” To an uncritical outsider it may at first appear, chiefly because of the images one associates with the word inner, that C, like B, is asserting the existence of strange goings on inside the ball, never suspected by the ordinary man or the physicist. In fact, however, if C is a philosophical panpsychist, he will not expect to find a brain or a nervous system or any kind of living tissue inside the ball, and he will disclaim any such assertion. Nor will he expect that tennis balls whisper gentle warnings to one another when they are alone. If he should start serving less forcefully in order to avoid hurting the ball, a professional panpsychist would undoubtedly advise him not to be silly, explaining that although their lives are governed by love and hate, balls do not get hurt in any sense that need concern a sympathetic human being. In other words, C does not disagree with A about what would be found inside the ball or about the ball’s behavior while it is in the can, and he is also not treating the ball any differently from the way A does—or at any rate no different treatment is logically implied by his opinion that the ball has an inner psychic life. B really contradicts A and, at least in the case of the balls we all know, he is quite certainly mistaken. C is not mistaken, but one begins to wonder whether he is asserting any facts not allowed for in the ordinary, nonpanpsychist view of the ball. A semantically sensitive observer might comment that ordinary people (and uncritical philosophers) are apt to suppose that they understand well enough what panpsychism asserts and that they proceed to dismiss it as silly or incredible (that is, as plainly false) because they regard panpsychism as a theory like B’s unusual opinion about the tennis ball. In fact, panpsychism is not like B’s opinion but like C’s, and the appropriate criticism seems to be not that it is a false theory but that one does not really know what, if anything, has been asserted.

SCHILLER. Let us now turn to the procedure of an actual panpsychist to see the full relevance of the preceding reflections. F. C. S. Schiller argued that inanimate objects, contrary to the usual opinion, take notice of other inanimate objects, as well as of human beings. “Inanimate objects,” he wrote, “are responsive to each other and modify their behavior accordingly. A stone is not indifferent to other stones” (Logic for Use, p. 447). Nor are stones indifferent to human beings: “In a very real sense,” he wrote elsewhere, “a stone must be said to know us and to respond to our manipulation” (Studies in Humanism, p. 443). It is “as true of stones as of men” that if you treat them differently they behave differently (Logic for Use, p. 447). It must be emphasized, however, that the responsiveness, the nonindifference, of stones is not quite what we mean when we talk about the responsiveness and nonindifference of human beings. How does a stone exhibit its nonindifference to other stones? Very simply: in being gravitationally attracted to them (ibid.). Nor are we “recognized” by the stone “in our whole nature.” It does not “apprehend us as spiritual beings,” but this does not mean that the stone takes no note whatever of our existence. “It is aware of us and affected by us on the plane on which its own existence is passed.” In the physical world we and stones share, “‘awareness’ can apparently be shown by being hard and heavy and colored and space-filling, and so forth. And all these things the stone is and recognizes in other bodies” (Studies in Humanism, p. 442). The stone “faithfully exercises” all its physical functions: “it gravitates and resists pressure, and obstructs ether vibrations, etc., and makes itself respected as such a body. And it treats us as if of a like nature with itself, on the level of its understanding, i.e., as bodies to which it is attracted inversely as the square of the distance, moderately hard and capable of being hit.” The stone does not indeed “know or care” whether a human being gets hurt by it; but in those operations that are of “interest” to the stone, as, for example, in house building, “it plays its part and responds according to the measure of its capacity.”What is true of stones, Schiller continues, is also true of atoms and electrons, if they really exist. Just as the stone responds only “after its fashion,” so atoms and electrons also know us “after their fashion.” They know us not as human beings but “as whirling mazes of atoms and electrons like themselves.” We treat stones and atoms as “inanimate” because of “their immense spiritual remoteness from us” and “perhaps” also because of “our inability to understand them” (ibid., pp. 442, 444).

Some of his readers, Schiller realizes, will “cry” that the views just reported amount to “sheer hylozoism,” but he does not regard this as any reason for concern. “What,” he answers, “if it is hylozoism or, still better, panpsychism, so long as it really brings out a genuine analogy,” and this, he is convinced, it does. “The analogy is helpful so long as it really renders the operations of things more comprehensible to us, and interprets facts which had seemed mysterious” (ibid., p. 443). Schiller illustrates his claim by considering the chemical phenomenon of catalytic action. It had “seemed mysterious” and “hard to understand” (presumably prior to the publication of Schiller’s “humanistic” panpsychism), that two bodies A and B may have a strong affinity for each other and yet refuse to combine until the merest trace of a third substance C is introduced, which sets up an interaction between A and B without producing an alteration in C itself. But, asks Schiller, “is not this strangely suggestive of the idea that A and B did not know each other until they were introduced by C, and then liked each other so well that C was left out in the cold?” To this he adds—and here surely not even the most hostile critic would disagree—that “more such analogies and possibilities will probably be found if they are looked for.” Nevertheless, panpsychism does not merely render the operation of things more comprehensible. It has a further virtue, to which Schiller alludes later in the same discussion: “The alien world which seemed so remote and so rigid to an inert contemplation, the reality which seemed so intractable to an aimless and fruitless speculation, grows plastic in this way to our intelligent manipulations” (ibid., p. 444).

Perhaps the most striking features of Schiller’s presentation are the constant modifications or retractions of what at first appear truly remarkable assertions. Inanimate objects are “responsive to each other,” but not the way in which human beings or animals are—they are responsive in being gravitationally attracted by other inanimate objects. The stone is “aware of us,” but not, of course, in the sense in which human beings are aware—it is aware on “its plane”; the stone “recognizes” other bodies and is “interested” in operations such as house building, but “on the level of its understanding”; it “plays its part,” but “according to the measure of its capacity”; atoms and electrons know us no less than we know them, but “after their fashion.” It is not, perhaps, unfair to say that Schiller takes away with one hand what he gives with the other, and it may be questioned whether anything remains. When one is told that the stone is aware of us one reacts with astonishment and is apt to suppose that a statement has been made that contradicts what an ordinary nonpanpsychist believes; but this turns out to be more than doubtful since the stone’s awareness, on its plane, seems to consist simply in being hard, heavy, space-filling, and colored. The stone makes itself respected and is interested in operations like house building, but in its own fashion, and this consists in gravitating, resisting pressure, and all the usual characteristics of stones, which are not questioned by those who do not subscribe to panpsychism. Schiller plainly believed that the panpsychist asserts (if he has not in fact discovered) facts about stones and atoms that are denied by, or whose existence is unknown to, the ordinary person and the materialist. He evidently did not believe that it was just a question of using words in different senses. But, if so, what are the facts he asserts and his opponents deny? Schiller’s qualifications remind one of a song in the musical Kiss Me, Kate in which a lighthearted lady sings of her numerous and constantly changing amorous involvements, adding at the end of each verse, “But I’m always true to you, darling, in my fashion; yes, I’m always true to you, darling, in my way.” How does the stone’s awareness in its own way differ from what other people would refer to as absence of awareness?

Empirical pretensions of panpsychists. Even if one is disinclined to go so far as to dismiss panpsychism as meaningless, there is surely good reason to dispute the empirical and pragmatic pretensions of certain panpsychists. We saw that Royce regarded panpsychism (among other things) as a hypothesis “to be tested,” but unfortunately he did not tell us anything about the way or ways in which this was to be done. Royce did indeed guard himself by maintaining that the mental processes in physical systems occur over “extremely august” temporal spans (The World and the Individual, second series, p. 226), so that a human being would be unable to detect a process of this kind. However, making the fullest allowance for this qualification and granting ourselves or some imaginary observer the “august” time span required by Royce’s “hypothesis,” this would still not do, since Royce omitted to inform us what such an observer should look for.

Schiller, it will be remembered, assured us that as a result of accepting panpsychism the previously “remote” and “rigid” reality “grows plastic … to our manipulations.” But he did not explain how and where these happy transformations would take place. Is a bricklayer who has been converted to panpsychism going to lay bricks more efficiently? Does a tennis player’s game improve if he becomes a disciple of Schiller? No, but perhaps the chemist will find catalytic action more comprehensible, and “more such analogies and possibilities” will make other “intractable” processes less “mysterious.” Regrettably, the opinion that panpsychism makes any of these phenomena easier to understand is the result of a confusion that hinges on an ambiguity in “comprehensible” and related expressions. Sometimes we attempt to make phenomena or correlations of events more comprehensible. In this sense, a phenomenon (for example, a certain disease or a plane crash) is comprehended or understood if its cause is discovered, and a correlation or a law becomes comprehensible if it is subsumed under a wider law (if, for example, the administration of a certain drug has in many cases been followed by the cure of a given condition, the correlation becomes comprehensible if we determine what it is about the drug that has this effect; and this is another way of saying that we subsume the correlation under a law). But at other times when we talk about making something comprehensible, we are concerned with explaining the meaning of theories or statements, not with the explanation of phenomena or of correlations. Unlike the first, this kind of problem may be regarded as pedagogical, and here all kinds of analogies may be helpful that do not or need not shed any light on the causes of the phenomena dealt with in the statements we are trying to make more comprehensible. It cannot, of course, be denied that an analogy such as the one Schiller offers may well make catalysts more comprehensible in this pedagogical sense—it may, for example, help schoolchildren to understand what a chemist is talking about. It is equally clear that such an analogy does absolutely nothing to make catalytic action more comprehensible in the earlier sense we mentioned, and it was surely in this sense that Schiller claimed panpsychism to make things less mysterious and easier to understand. It is difficult to believe that either Schiller or any other champion of panpsychism would be satisfied to have the theory regarded as no more than a pedagogical device in the teaching of natural science."

(Edwards, Paul. "Panpsychism." In Encyclopedia of Philosophy, vol. 7, 2nd ed., edited by Donald M. Borchert, 82-93. Detroit: Thomson Gale/Macmillan Reference USA, 2006. pp. 90-2)
<QUOTE

[Gertie]

There are intelligle ways to consider panpsychism.

We can simply see it as a possible explanation for conscious experience when asking the intelligle question - Is conscious experience an emergent property of physical stuff/processes, or is it fundamental?

We can consider whether there is ''something it is like'' to be a stone or a tennis ball? That's an intelligle question.

The problem in answering these intelligible questions, is that we don't know how to formulate an answer.

These aren't (currently, and perhaps in principle) scientifically testable questions.

And if there is 'something it is like'' to be a stone, we don't know what that might look like.

We can guess it might be something like experiencing gravitational pull, implying conscious experience plays a role a physical causality, which would make sense in terms of conscious experience being fundamental, but that might not be ''what it's like'' to be a stone, it's just a possibility based on something observable to us.

And it's true we have a physicalist explanation for gravity and stone behaviour which doesn't require the stone to have a ''what it's like to experience gravity'' .

However we have a physicalist explanation for the behaviour of conscious beings like humans too, which doesn't require humans having the experiential properties of ''what it's like to be a human''.

So the intelligibility problem doesn't lie in the possibility of panpsychism, if there is one it lies in the nature of conscious experience itself. That we don't have an explanation which fits our (current) physicalist model of what the world is made of and how it works. If we look beyond that model for the explanation, the explanation wouldn't be expected to be 'intelligible' in terms of the model. Or in terms comparable to ''what it's like'' to be something very different like a complex biological entity such as you and me.

Re overall credibility - what basis do we have to judge that on?

[Consul]

Is it plausible to adopt an anything goes principle of the non-uniformity of nature that renders all analogical inferences invalid? Why should we expect things very dissimilar from animals to have the same power to realize conscious states? Shouldn't we rather expect them to lack this power owing to their extreme physical dissimilarity?

That's a different point. The point here is that the one yardstick we have (similarity) to assess whether something is conscious, can't be used on very dissimilar things. So to use similarity to establish whether conscious experience is present isn't sound.
That does leave us with a potential anything goes problem. Because it's a problem the scientific method can't tackle, and inference from similarity can't either.
So we're left with trying to assess whether conscious experience is ontologically emergent or fundamental (or something else...?) by some other means. But the scientific method, and similarity, ain't it.

The method of comparison is part of the methods of science, and it is epistemically valuable precisely because nature isn't a realm of anarchy or chaos where anything goes.

("to compare" = "to mark or point out the similarities and differences of (two or more things); to bring or place together (actually or mentally) for the purpose of noting the similarities and differences" – Oxford Dictionary of English)

Panpsychism is like "pancorrosionism", the view that all chemical substances are corrosive independently of their molecular structure. Would any chemist take this view seriously? I don't think so. Scientific comparisons between chemical powers and chemical structures reveal objective similarities and dissimilarities between them, on the basis of which legitimate conclusions regarding what chemical substances have (or lack) what chemical powers can be drawn.

The analogical inference from my own consciousness to other human consciousnesses is well justified, given that we belong to one and the same species. It would just be absurd to believe that I am the only conscious member of my species. What a miraculous accident of nature that would be!

Again, that's a different point. You said there's nothing we know about the physical structures of computers, rocks and atoms which requires or justifies thinking of them as having conscious experience(well you shifted the goalposts to psychological subjects, but I'm not arguing for that).
I said the same can be said of humans. Therefore it's not a valid point.

Yes, it is, because we know that subjective experience is part of human psychology; so it's highly reasonable to include references to it in explanations of human behavior—not in all cases, but in many ones. For example, why did Mary go to the dentist? Because she couldn't stand the nagging toothache anymore.

Me shifting the goalposts…? Physicalistic panpsychism (with "pan-" taken quite literally) is the view that all physical objects are psychological subjects (subjects of mentality).

Why should we accept that panpsychistic anything goes premise with regard to the material substrates of consciousness?

Panpsychism is a possible explanation for conscious experience. You said if we start with the version of panpsychism you mention then analogical reasoning is pointless. I agree, and pointed out that even with analogical reasoning we don't know how to know if rocks, atoms, etc are conscious.

I reject the anti-analogical anything goes premise, because it presupposes panpsychism.

Anyway, panpsychism simply claims as a brute fact that all physical objects are mental subjects. It doesn't explain in any way how conscious states of single particles, atoms, or molecules are realized in and by them.

If a nonbiological phenomenon can be fully explained in nonpsychological/nonphenomenological terms, then consciousness isn't necessary for it. There are no known nonbiological phenomena the explanation of which requires the postulation of conscious events as explanatorily relevant causes or factors.

Again, the same can be said for humans.

No, it can't, because humans are known to be subjects of experience; and—pace epiphenomenalism—their experiences do seem to make a difference to their behavior or actions, such that it would be very unreasonable to exclude them from psychological explanations of human behavior. Can you imagine a psychotherapy that completely ignores what's going on in your conscious mind, including your thoughts?

If particle consciousness exists, then whatever experiences particles have, they must belong to the same basic kinds of experiences we have and know—sensation, emotion, imagination (cogitation)—; for otherwise they wouldn't be experiences at all, since by definition to be (phenomenally) conscious is to undergo some sensation, emotion, or imagination.

Simply saying all forms of consciousness must be like human/biological consciousness doesn't make it so. There might be 'something it is like' to be a particle or computer or daffodil which we wouldn't recognise precisely because it's not similar to 'what it's like' to be a human, or dog, or bat.

The meaning of our concept of subjective experience is determined with first-person, introspective reference to our own kinds of subjective experience; so if the so-called experiences of particles, atoms, molecules, crystals, rocks etc. are totally dissimilar and essentially different from human experiences, then you're no longer justified in calling them experiences, since they might then be something else, something nonexperiential
Postulating incomprehensible and inscrutable alien minds or consciousnesses is in effect no different from postulating alien somethings-I-know-not-what!

Why assume a particle would experience colours, or biological type sensations? I'm challenging the expectation it would be anything like biological consciousness. Even with biological species there's so much variety. I'd expect non-biological consciousness to manifest very differently.

If there is such a thing as particle consciousness, what kinds of particles are subjects of experiences, and what kinds of experiences do they have?

It's plainly self-contradictory to say that X is a subject of experience, but its experiences are neither sensations, emotions, nor imaginations (simulated sensations).

[Consul]

Me shifting the goalposts…? Physicalistic panpsychism (with "pan-" taken quite literally) is the view that all physical objects are psychological subjects (subjects of mentality).

According to mereological universalism, for any two or more objects there is another object which is their mereological sum. If this is true and panpsychism is true too, it follows e.g. that the sum of the moon and the Eiffel tower is an object which is itself (as a whole) a subject of experience. Does this sound absurd enough!

[Sy Borg]

Panpsychism is a dead end from the scientific perspective.

Yes, you already said that, and (as far as I can see or understand) you are correct to say so. But you have not answered, or even acknowledged, the question Sy Borg asked: "So the untestable is not worth considering as a possibility?"

Does panpsychism make any sense as a real (natural/physical) possibility? Is a world where it is true coherently imaginable and intelligible?
You can certainly think or say e.g. "Tennis balls are conscious beings" without contradicting yourself logically; but if you do, it is not clear that you really understand what you are thinking or saying. What can make a tennis ball conscious? How can a tennis ball become and be conscious? What kind of (conscious) minds do tennis balls have?

Sure, it does. But positing tennis balls as conscious misses the point.

I think this ultimately depends on whether one thinks qualia is real or just a distraction. It depends on whether thinks micro-consciousness is possible. Personally, I don't know if these things are true. Even if I consider the odds of it being true, it's not like considering the odds that an armchair is orbiting the Moon. In this case, we don't even know enough to consider the odds of panpsychism being true or not, or if looking at reality as conscious or not is a actually skewed perspective due to cognitive biases.

The nature of being is very strange and not readily apprehended by the scientific method. All I am sure about is that no one else knows either. I would support many of your ideas if they were presented as possibilities rather than facts, an acknowledgement that science in the 21st century still has a long way to go.

[Atla]

Psychological experience is what experience is like in advanced, alive nervous systems.
Experience in a rock could hardly be called psychological, I think it's better to imagine it as something like: a mostly still image of TV static.

The version of panpsychism where rocks and particles etc. have "individual minds" and "individual inner subjectivity" I find absurd to the nth degree tho.

[Consul]

There are intelligle ways to consider panpsychism.
We can simply see it as a possible explanation for conscious experience when asking the intelligle question - Is conscious experience an emergent property of physical stuff/processes, or is it fundamental?
We can consider whether there is ''something it is like'' to be a stone or a tennis ball? That's an intelligle question.
The problem in answering these intelligible questions, is that we don't know how to formulate an answer.
These aren't (currently, and perhaps in principle) scientifically testable questions.
And if there is 'something it is like'' to be a stone, we don't know what that might look like.
We can guess it might be something like experiencing gravitational pull, implying conscious experience plays a role a physical causality, which would make sense in terms of conscious experience being fundamental, but that might not be ''what it's like'' to be a stone, it's just a possibility based on something observable to us.
And it's true we have a physicalist explanation for gravity and stone behaviour which doesn't require the stone to have a ''what it's like to experience gravity'' .

However we have a physicalist explanation for the behaviour of conscious beings like humans too, which doesn't require humans having the experiential properties of ''what it's like to be a human''.
So the intelligibility problem doesn't lie in the possibility of panpsychism, if there is one it lies in the nature of conscious experience itself. That we don't have an explanation which fits our (current) physicalist model of what the world is made of and how it works. If we look beyond that model for the explanation, the explanation wouldn't be expected to be 'intelligible' in terms of the model. Or in terms comparable to ''what it's like'' to be something very different like a complex biological entity such as you and me.

Re overall credibility - what basis do we have to judge that on?

Yes, the question Are tennis balls mental subjects? is understandable. But as soon as you try to imagine a tennis ball actually being a mental subject by imaginatively ascribing mental properties to it, it becomes questionable that you really understand what you are imagining—especially when the "real essence", i.e. the material constitution, of tennis balls is fully known to you, such that you are aware that there is nothing in them which is remotely like a nervous system or a brain.

Imagining experiencing tennis balls seems as straightforward as imagining talking dogs, so we are inclined to believe that there is nothing impossible about them. Look, we can even see talking dogs in movies, so what's impossible here?! But this naive and superficial way of imagining or thinking collapses as soon as you take the real, natural/physical essence or nature of tennis balls and dogs into consideration. For if you do, you will see that there is a perplexing incompatibility between being a tennis ball and experiencing, and between being a dog and talking (in a natural language such as English). So when you imagine an experiencing tennis ball or a talking dog, there is just an imaginative illusion of real possibility. Panpsychism is guilty of committing ontological category mistakes by ascribing mental properties to things the having of which is incompatible with the things' physical essence or nature, with what kind of things they are.

[Consul]

…Panpsychism is guilty of committing ontological category mistakes by ascribing mental properties to things the having of which is incompatible with the things' physical essence or nature, with what kind of things they are.

Interestingly, most panpsychists regard their view as perfectly naturalistic; but their attributions of mental properties to all sorts of physical objects are actually no different from supernaturalistic (occultistic) ways of thinking, because they are equally ontologically counterintuitive:

QUOTE>
"[R]eligious concepts invariably include information that is counterintuitive relative to the [ontological] category activated.
'Counterintuitive' is a technical term here. It does not mean 'strange', 'inexplicable', 'funny', 'exceptional' or 'extraordinary'. What is counterintuitive here is not even necessarily surprising. That is, if you have the concept of cologne-drinking. invisible persons, and if everyone around you talks about these visitors, you cannot really register puzzlement or astonishment every single time it is mentioned. It becomes part of your familiar world that there are invisible persons around who drink cologne. In the same way, Christians and Muslims are not surprised every time someone mentions the possibility that an omnipotent agent is watching them. This is completely familiar. But these concepts are still counterintuitive in the precise sense used here, namely 'including information contradicting some information provided by ontological categories'. (...) [W]e must remember that the ordinary sense of the term 'counterintuitive' may be misleading. (The neologism 'counterontological' might be a better choice.)"

(Boyer, Pascal. Religion Explained: The Evolutionary Origins of Religious Thought. New York: Basic Books, 2001. p. 65)

"[T]here is only a rather short Catalogue of Supernatural Templates that more or less exhausts the range of culturally successful concepts in this domain. Persons can be represented as having counterintuitive physical properties (e.g., ghosts or gods), counterintuitive biology (many gods who neither grow nor die) or counterintuitive psychological properties (unblocked perception or prescience). Animals too can have all these properties. Tools and other artifacts can be represented as having biological properties (some statues bleed) or psychological ones (they hear what you say). Browsing through volumes of mythology, fantastic tales, anecdotes, cartoons, religious writings and science fiction, you will get an extraordinary variety of different concepts, but you will also find that the number of templates is very limited and in fact contained in the short list given above.
Indexing supernatural themes in this way has all the attractions of butterfly-collecting. We know where to put various familiar themes and characters in our systematic catalogue of templates, from listening trees to bleeding statues and from the Holy Virgin to Big Brother."

(Boyer, Pascal. Religion Explained: The Evolutionary Origins of Religious Thought. New York: Basic Books, 2001. pp. 78-9)
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[Pattern-chaser]

Panpsychism is a dead end from the scientific perspective.

Yes, you already said that, and (as far as I can see or understand) you are correct to say so. But you have not answered, or even acknowledged, the question Sy Borg asked: "So the untestable is not worth considering as a possibility?"

Does panpsychism make any sense as a real (natural/physical) possibility? Is a world where it is true coherently imaginable and intelligible?
You can certainly think or say e.g. "Tennis balls are conscious beings" without contradicting yourself logically; but if you do, it is not clear that you really understand what you are thinking or saying. What can make a tennis ball conscious? How can a tennis ball become and be conscious? What kind of (conscious) minds do tennis balls have?

I can't quite see what you're getting at here. Some kind of attempt at a reductio ad absurdum, perhaps? What is clear is that you have not answered the question. Again. Since I find it difficult to believe that you are unable to answer this simple question, I conclude that you choose to refuse to answer. I am at a loss to see why, though.