1_treefall
"If a tree falls in a forest, and no one is around to hear it, does it make a sound?"
Have you ever tried to solve this riddle?
I don't mean in the cheeky literalist way, where the answer is yes because a tree falling must produce a vibration of some kind, and sound can be defined as a result of vibration.
No, the intent of the riddle is to consider the provability of the circumstances surrounding an event where there is no evidence nor witness. It's a riddle because it's common sense that a sound would happen without an observer, but that that assumption could potentially be in error.
So what if I say yes and you say no? Before addressing the conflict, take a step back and ascertain whether there even is a conflict. Did we imagine the same tree? The same forest? Because the riddle is such a simple line of text, the details are left entirely to imagination; I suggest that, no, the chances of us imagining the same scenario are infinitely small. Effectively there can be no singular correct solution because there is not a singular scenario to reference.
Now, I have to go into why any of that matters. If you look at the wording of the riddle, you'll see why it is not sufficient to accept a single subjective conclusion. "does it" may as well be "will it", which is much different from "can it". This means that it must be proven with no exceptions. Naturally, this leads one back to the literalist realm of answers, but I'll ask you to ignore that for now in favor of examining a different idea: how real must the scenario be?
With heavy reliance on imagination, one could easily imagine a set of extravagant - even supernatural - circumstances that could force a certain answer. The riddle does not exclude such things explicitly. So the riddle is impossible to solve, because it will always be possible to imagine at least one scenario for both "yes" and "no".
Implicitly, you're supposed to think of a realistic scenario, of course. However, imagination must be a factor because it is linked to observation, which is absolutely a factor. We are not machines; we process and configure our sensory data into observations - likewise we can imagine an event without direct sensory data while being able to imagine what the sensory data from the event would be. So what makes something real? I will posit that an objective reality is not necessary to validate the quality of "real"; that a daydream is just as real as the tree and the forest featured in this riddle.
Even if the premise scenario were changed from text to a mute video, answers could vary. Even if you and I both stood watching it in real life, our answers could vary! It sounds silly - obviously if there are multiple direct observers, it's not even a riddle anymore, just a comparison of factual data. Let me put a twist on that. Let's say there are 100 observers for this real event, and that you are 1 of them. Afterwards, everyone is asked if the fall of the tree made a sound - and all 99 of the others say "no" while you say "yes". Would you doubt yourself? Would you doubt them? Something is clearly not right. But who is wrong, why are they wrong, and how can anyone prove it? It's not actually provable without reading everyone's minds. No, I will suggest a simpler explanation to circumvent this problem: the existence of objective reality is entirely unverifiable because everything must be an interpretation of one's subjective reality. In other words, there is only a problem when one asserts that all observers of an event must have the exact same experience - further, that every observer can have wildly different and contradictory experiences from the same set of stimuli. ...And that is from a scenario of minimal imagination.
If you think about this for a minute, it might not seem very useful. I will add another metric: belief/certainty. If you and I observe an event and conflict in our interpretations, but I am less certain of my interpretation than you are of yours, then your reality is more real than mine is (as far as that event is concerned). This does not necessarily mean that your subjective reality is closer to objective reality than my subjective reality, but that wasn't a goal anyway. So what does it mean when your certainty exceeds mine within (relatively) the same boundaries? It means that the determining factors of what is reliably real to you were more thoroughly crystallized than the similar factors were for me. One common interpretation of what this means is that the reality you experienced has more details that can be recalled than the reality that I experienced. So it is possible to dismiss my answer of "yes" based on my inferior certainty (whether this is wise is another matter).
Finally, while it's simple enough to place two beliefs on a scale and compare them, what of the earlier example of 99 contradicting realities? To make the same dismissal based on certainty, it is not sufficient to make 99 individual comparisons. The exact formula I cannot properly suggest, but let's speculate a simple sum in order to complete the point. The total sum certainty of all 99 contradictions would need to be inferior to the certainty you have in your reality - a tall order.
In loose summary, the answer to the riddle is "Whatever I say the answer is, and the burden of proof is on everyone else, but only to believe I'm wrong more strongly than I believe I'm right."
2_the range of conviction
Extending the previous section into the realm of verifiable things, we can find other metrics of complication. Here, I will talk about the range of conviction. Not a physical range of distance. A measure of how readily one's belief in something can be re-affirmed, and at what depth it can be re-affirmed. Because, much like a person might check a dictionary when they're unsure about a term's definition, a person might have some strategy/source by which they can check each of their beliefs.
Example: the logic trick of "every apple in my hand is red". The point of the quote is just a lesson in the rules of logic, but the cornerstone of it involves direct verification. It's meant to be said in person, while showing that there is nothing at all in your hands. While the layman gets caught up in assumptions to create confusion over how the statement can't be true when there are no apples at all, the person familiar with logic recognizes it as a true statement so long as there is no verifiable contradiction. That is, the logic student will immediately check for non-red apples held in the person's hands.
Briefly, I should explicitly say that the layman's confused view is not a factor here, as can be extrapolated from the previous section. Because they imagined a different claim than was made, they can no more contradict the logic student than two people imagining different trees could contradict each other in the previous section. It isn't a worthless view, but it isn't important for this section.
When the claimant is only a few meters away, this is trivial to verify with the naked eye. What if they are 100 meters away? The naked eye won't be a reliable method of verification. A tool could be used, like binoculars. What if they are 100 kilometers away? You can't reliably view it with your eyes then, without some extravagant setup. Perhaps you could use satellite imaging, if you trust there to be highly accurate color portrayal. You could even have a third party verify in person and send you a message to verify. Isn't this weaker, though? Not simply because of great physical distance, but because the verification strategy had to change to something with at least a slightly larger margin of error. Now, what if they were in an undisclosed location? You can't verify at all, unless you make character judgements about them to assume their claim is true or false.
The range of conviction is pretty much the same - it's the measure of how reliable any method of verification is.
I should go ahead and mention "CE field", as a term I've made up. It stands for Chimerical Equity field, which by definition, chimerical equity just means 'things have a weird way of working out' (or even 'the lord works in mysterious ways'). Applying the concept to a "field" only really makes sense as I explore some of the specific factors here - this is all just a long explanation of what I summarize as chimerical equity. Now, while I mentioned earlier that the range of conviction shouldn't be imagined as a literal physical range of distance, you can imagine it being close enough, as proximity can just be another method of verifiability. This is to say that the range of conviction acts as the soft boundaries of every CE field.
3_conflict and compromise between competing realities
So far, I have not addressed any sort of conflict or compromise between competing realities. It's simple enough to just claim that two realities fail to have sufficient overlap to generate any sort of conflict or demand a compromise, as there's pretty much always some difference, however minute. But this is not useful. Demanding 100% of details match, or even 99% of details matching, this is just an academic quibbling over influence, simulacrum, and etc. Well, let's be more interesting, starting here.
We could stick with the example of the falling tree from section one, or we could use something like a movie that is interpreted differently between multiple viewers. Perhaps the movie example would work better, as it more easily escapes hard science (and so we do not have our time wasted by literalists). Let's say you and I both watch a movie, and that afterwards, we speak of what the future holds for the characters of the movie. This demands two major factors, I think: imagination and understanding.
Understanding is knowing how the particular setting of the movie operates, along with an understanding of all the characters. There is of course going to be a lot of unspoken knowledge drawn upon here, as you and I probably have very different views on human psychology, social dynamics, and other such things - but we have to let this go unless we are going to have a lengthy discussion about some movie I just made up (and most people would balk at such a discussion in the first place, so I don't believe I am being lazy here).
Imagination, here, I am meaning more one's ability to process knowledge entirely within their mind. It's pretty closely tied to understanding, but a strong imagination can sort of make up for poor understanding, and vice versa. When we try to determine the future of characters from this movie we watched, we both must literally imagine one or more speculative futures.
So let's say that we both come to drastically different conclusions of what the future for those characters holds. This is essentially the divergence of one reality into two different realities. The two realities occupy the same space, though, so the divergence creates a conflict that must resolve. That space is the imagined future of the movie. While the future is theoretically uncertain, it is lazy to bring that up as a final point, so we are going to dismiss it and demand some certainty - this is the future of a fiction, after all, I don't think it is unreasonable to affirm a future that has no method of hard verification. We have our own intuitive systems for verifying such things. It is basically the "Does this make sense?" test. When we tell each other our imagined futures, the listener automatically will consider and determine if it makes sense. They will reference their own understanding, imagination, but also some subtler cues like the storytelling abilities of the speaker, or personal bias between us.
I think it's a fair assumption that any product of our imagination and understandings will make sense to us...let's go ahead and say that "making sense" is a numerical trait by percentage, and that anything we come up with, will be 100%. A 0% would be something that has some fundamental contradiction to us, and sounds like nonsense. Well, even though we both shared our 100% ideas with each other, we are not left with two 100s. We have something more like one 100 and one 90; we each are confident in our own imaginings, but find the other to be lacking in some way. Okay. But we are not content to just write the other person off as wrong, so we discuss our ideas. Gradually, that 90 becomes a 95 as we absorb additional data, and the additional data brings our 100 down to a 99. While we could probably discuss it long enough to reach equality, we probably will stop after becoming bored. Once that 100 stops being 100, anyway, it is evidence that the idea we once had full confidence in is no longer representative of our understanding and imagination; we must re-answer the question to re-attain that 100. And on so doing, we can share our answers and influence one another in a cycle moving towards an equilibrium (likely never reaching it), but it's a little less boring than just direct discussion.
Well, what's the point, right? Check this out: the summary affirmation of a reality is the total sum of "does this make sense" by all observers. If your numbers perfectly reflect my numbers, then we maintain a conflict. This is not realistic! It is much more realistic for one of us to gain a stronger affirmation than the other. That is the process of compromise between two competing realities, even though it's been represented as a compromise between two observers. I would like to assert that competing realities naturally move towards compromise, but the rate at which they do so is entirely dependent upon subjective affirmations of observers (not merely how many observers observe the idea, but how much each observer cares). The state of reality in absence of observation is the only true "objective reality", but it is unobservable and so not really able to be discussed without continuously destroying the topic we chase.
Of course, just because something is not realistic, does not mean it never happens. If we maintain a perfect conflict between our views, then the next step is to introduce additional observers and/or additional data. Every such addition greatly decreases the likelihood of a maintained conflict. I don't want to get into it in this section, but one can also create their own observers to help tip the scales.
I would like to point out that this has nothing to do with the truth. This is about the affirmation and denial of a reality. A reality being denied is not the same as it being false. By contrast, a true reality is not necessarily one that is affirmed. The ever-present philosophical pursuit of Truth is not here, and does not belong here.
One more thing. Realities still compete with each other, even without mutual observers clearly existing, because the observer is only the source of affirmation and denial. Affirmation and denial change the.."strength" of existence, so to speak. But they are not used to turn nothing into something or something into nothing. An idea (and by extension, a reality) may exist with zero observers - no, I will go as far as to say that infinity ideas and realities exist, even if no one has observed them.
4_distributed belief structures
An interesting phenomenon occurs from the use of distributed belief structures. You can think of "distributed belief structures" as being like religion or folklore. It is a structure of belief (a set of ideas, even) that is distributed across multiple believers. As mentioned, the more affirmation an idea receives, the stronger it becomes, and the more real it is (but not necessarily more true). So an idea believed by many people is generally more real than an idea believed by one person.
We'll use an example of religion. Let's say there is a society, and that society develops its own religion. This society exists in a vacuum for now. All of the people in this society believe in their religion. To each of them, the ideas of their religion are reality. Their god really does exist, the evidence exists as well. Being a god, the god doesn't have to exist in the same way a person does. What sort of life does the god live? What does the god dream of? Does the god eat food? Does the god get cold during winter? None of these questions may be answered by the religion, but they gradually get answered by the imagination of curious believers. It's possible none of the questions get answered, if somehow all believers are unimaginative or lack curiousity. Either way, these answers or non-answers further develop or restrict what sort of existence their god has. The god is an idea, a shard of their beliefs - and so being, is subject to the imagination and understanding of all believers.
Putting it more plainly: gods are products of belief. Gods can live like men, or dogs, or titans, or cosmic horrors - anything, according to belief. This belief is rather like their lifeblood, or the metaphysical umbilical cord connecting idea to mind. The greater the belief, the stronger the god. The weaker the belief, the weaker the god. And so, the method of killing a god or an idea becomes clear: destroy all belief in it. The simple method would probably be genocide, followed by record destruction, monument erasure, and maybe even destruction of the destroyers. Well, I say "kill", but I'm talking about functional levels of existence; a "corpse" remains, forever, hidden in the unobserved.
Now, let's surround the above society by other societies which have different beliefs. The conflict of the beliefs only really apply where observers are confronted with the evidence of different beliefs. Ideas gradually get exchanged, as normal, and belief systems shift to accomodate new ideas or to reject them.
If the man-like god of one society attempted to walk into another society (outside the range of conviction of the believers), the attempt would fail. The god exists only within the range of conviction, so it would require a number of believers to come with it in order to succeed. But upon entering the range of conviction of opposing beliefs, the god would start to weaken. If all of those believers suddenly died, the god would disappear (effectively, the reflection of the belief would vanish) and reappear at some other location with a more stable belief structure (pretty much always the home society, or whatever location they believe it might happen). The god could potentially be killed, rather than the believers, but the possibility and process for that are really complicated because of all the precise beliefs involved. If the god were actually killed or disempowered or captured or whatever, and the believers of that god affirmed the results according to their beliefs, and then they go home and convince the rest of the society, then the fate of that single reflection becomes the fate of the idea, as there would be no contradictory belief to fall back on.
Just one contradictory belief would be enough to save the god, although the god would be very weak then, and likely unable to be reflected in any sort of manifestation. If this happened, there would effectively be a split of the original idea. The majority affirmation would uphold the existence of the captured/killed/etc god, while a minority affirmation upholds the existence of the original god. Those two beliefs contradict and reject each other, of course, and it's on such a scale that the majority basically "wins". Now, if exactly half of the society changed their beliefs while the other half did not, the society would basically split in two and probably have a civil war. Such a large, local rift would cause a conflict that can't compromise on its own. The people would have to settle it somehow. It is possible to have such a scenario result in a war of gods, as the believers' ideas get turned around to support their own affirmation by rejecting contradiction. It's be a big mess, of course, and quite possibly destroy all nearby landscape, depending on what sort of powers the gods were affirmed into holding. That kind of war of ideas actually has a clean metaphysical result, though, as it's plain to affirm the events unfolding in front of everyone's eyes.
Of course, being gods, if you start changing the state of their existence in these ways, you can quickly get some crazy results within the range of conviction. Like, if a god is controlling the rising of the sun, them dying means that the sun cannot rise again, creating an area of eternal night. Outside observers would probably have to affirm such an anomaly into their own belief structures, because if everyone around it rejected that it's happening, whole chunk of conviction territory (the space that's covered in eternal night) would be banished to an alternate reality or plane of existence - one where their existence is affirmed in some way by distant observers. This is pretty rare to happen, though, because most people will affirm bizarre events into their beliefs. And that rarity eventually standardizes the occasional bizarre event, so they are even more readily affirmed - often by being pre-emptively explained by belief structures created by people who have already affirmed several bizarre events.
Now, these kinds of distortions are only tied to physical spaces if the beliefs align just right. Most of the time, they will be tied to the range of conviction of believers. So, a person from the eternal darkness society, when they travel to another society, they would actuall appear to be cursed, as they slightly darken their surroundings as their personal reality rejects the sunlight around them. Like so, when that person looks up, they will never see the sun, even if everybody around them sees it. They won't recognize the shadows of others as being any stronger than moonlight could produce, and their vision will be somewhat impaired just like during the night. Artificial light like fire still works fine for them, so they may carry a lantern or torch everywhere, which could cause other sorts of rumors about them other than simply suffering a pitiable curse. They will probably make for poor burglars, as they don't understand that daylight exists for other people (they believe everyone is lying for some reason), so they would try to sneak in broad daylight. Similar to dimming light near them, they also dim the heat of the sun, so on the hottest summer day, they might be seen wearing heavy clothing. Maybe they'd be valued as portable air conditioners for field workers. This 'curse' would get stronger, the more eternal night believers are in the same place.
Now, if the society that the eternal night believer travels to rejects the effects of their beliefs (like, the society largely rejects the idea that darkness can follow a person, or that anomalies exist), then the effects shrink enough to where they can be excused as more believable phenomena. No matter how much it's rejected, though, the eternal night believer CANNOT see the sun or any sunlight, because that's the core of the belief they hold. You could trick them into believing that your society has built a false sun that only shines for them, though. But it's about those fundamentals. The beliefs that are deeply held resist contradiction, and the path of easiest compromise is generally taken. If every society got together and conspired to do so, they could effectively unify the world vision for even the eternal night believers, by tricking them on a massive scale. Gaslighting is a legit warfare tactic, but it's complex and abstract enough to where it's extremely rare (there will be no vast conspiracy to save the eternal night believers).
The situation isn't actually reversed if an outsider comes to visit the society of eternal night. Because the outsider has already affirmed the existence of the darkness phenomenon, it is real to them, but it plays by the rules of however they affirmed it into their own belief structure. If it's some wacky rule, like the zone of darkness is a bubble filled with poison gas and the ground covered in jewels, then they can hold their breath and pull out a bunch of jewels (that only those of similar belief could affirm the existence of). Though that'd probably lead to a lot of invading rogues, and potentially the ability for these eternal night believers to gain resistance to poison within the society which believes they live in a big poison cloud.
The flashy stuff has been covered, but there's a lot more subtle things going on with distributed belief structures. Like folklore or oral history. A lie told to children, if never corrected, becomes the truth for those children. Correction can become impossible if it concerns the past, like a tale of an ancestor's heroic military career. This sort of thing generally has little effect worth mentioning, but it leads into the next section.
5_prison of opinion
Something a little different happens with beliefs directed towards living people. Because the strength of conviction in belief is a greater factor than number of believers, and because it is usually safe to assume that people know themselves better than any other person, there is a natural resistance to the sort of alteration mentioned in the previous section. The resistance is greater the more confidence the target person has in their identity, basically.
Lying to yourself is ineffective because you don't truly believe it. Further, it's not as if people are consciously aware of what their actual beliefs are (unless you're a philosopher, perhaps). So even if you have 100% confidence in who you are, if it's built on a lie, it won't work well as resistance. "Fake it 'til you make it" does not work with this system because you can't fake your beliefs.
It should be obvious that the better you understand another person, the greater influence your beliefs about them will have. This is because the understanding puts your beliefs to the test, which thoroughly raises conviction.
Normally not possible, but if there is an exceptional case where, say, I understand you better than you understand yourself, your belief in yourself is still necessarily stronger than my belief in you. This is because of the experience of life; no amount of understanding can trump the conviction imparted by real experience.
So, if a person has a weak sense of self, they will end up getting warped by the beliefs of others who observe them. The weak sense of self, however, also makes such changes more noticeable to the person because lacking that internal grounding expands their internal sensory range. So this person with a weak belief in who they are will probably end up burning themselves out trying to actively deny this influence.
Psychology intertwines here a lot, and I'll have to leave it to your imagination for now, because it would be a very long section if I tried to cover all the exceptions and exploitations.
One more thing, though: none of that is the "prison of opinion". The real prison of opinion happens when you die. When you die, your personal reality goes with it, leaving only whatever stains it made on other personal realities. The afterimage of you still remains in everyone who knew you, and the accuracy of that image is based on their beliefs about you. Since you cannot provide any sort of contradiction or resistance, whatever they believe about you is your reality now. If they believe you went to a place of eternal torment or a paradise, it is true in their reality. There are most likely a bunch of these images at play, and they are now the primary influence on what your reality is - and there is literally nothing you can do about it, even if they believe you have the agency and power to do so in death.
Of course, it's not really you. You're dead. It's just the most "you" you that exists now. So it effectively is you. Well, what's the non-personal reality? There could be a hundred different beliefs about you. They can't all be reality within the same space (plane of existence); there has to be one. That one reality is basically a mish-mash of all of those beliefs, according to a compromise of beliefs. Only, no person can actually observe the resultant reality. As people talk about you (if they talk about you), they'll gradually share their beliefs with others and the ideas will intermingle as I've described previously.
For the average guy, this doesn't matter all that much. A folk tale about a giant man could eventually have enough belief to generate a giant skeleton as proof. But that won't happen as long as the person the folk tale is about is still alive. A hero can gain supernatural ability in response to people who believe in him. If it gets wild enough, he could be resurrected after death.
6_echoed observation
So I've established that you can't exactly force a person to change with belief, but there's a different sort of exception I need to cover: the creation of new people.
Let's say there is a city with some societal problems, and that they start blaming the mole men for it. The mole men weren't real, of course; it's just a scapegoat. But it's a successful scapegoat, and eventually it's a common belief in the city. Well, now mole men really do exist. They can exist now either as illusions or half-men.
Illusions appear to be real until scrutinized, at which point their existence will sort of implode due to contradictions. There's not much else to say about illusions, so I'll carry the example with half-men. Half-men are like empty shells of men, and the empty parts organically fill over time. Half-men can ultimately become able to generate CE fields.
While this process can be used to create monsters, that's not what's happening in this example. The belief is that the mole men are like men, but with twisted motives and unusual traits that allow them to flourish under the surface. While not coordinated, there will be some coherency in the general belief of how mole men live and why they keep sabotaging crops or whatever nonsense. Things will, of course, become worse for that city as their scapegoats get out of hand. Because it's become such a culural fixture for the city, though, it may be impossible to destroy the mole men - really depends on the details of all the beliefs.
But the mole men still exist with enough human traits to undergo natural progression through human invention. If they weren't believed to have a society, they'll probably invent it anyway. Given enough time, they'll have language, art, and tools. Now, this is most likely a disaster for this city, but with enough political will there could be negotiation and symbiosis. The only way for the organic evolution of these mole men to stop is total genocide. If that doesn't occur, they'll eventually be internally robust enough to have complex beliefs and CE fields. Once they gain the protection of CE fields, they gain the ability to contradict the beliefs they were imprinted with, also.
I should take a moment to point out that human psychology is absolutely necessary for these mechanics to function. If the mole men were just mindless monsters, they'd never really evolve. Similarly, if they held some incomprehensible alien psychology, they'd never really evolve. I'm basically categorizing life into three groups: human (even if not literally homo sapien), sub-human (like beasts and insects), and alien (like an eldritch abomination). Only the human group gets to generate the chaos of chimerical equity.
For your easy baked-in metaphor, there's a period of time there where the mole men can be manipulated by the city simply from them changing their beliefs about them, which are rooted in a refusal to accept responsibility (which would require some sort of cultural revalation or revolution). Metaphors make easy plots, and all that.
Now, that was the creation of believers. It can't be done directly, but it can be done. Next, there's an easier thing that can be created: observers. An observer doesn't necessarily have its own CE field, but it can have an echoed boost towards the belief of people observing those observers.
Example: say I believe that grass is razor sharp, and that I'm enough of a hermit to make it happen with conviction. If a dog walks on that grass and cuts up its paws on it, that's a direct affirmation of my belief. The dog was an observer - it observed the reality. Now, this is just normal psychology, but when a person has their beliefs affirmed by outside evidence, those beliefs become stronger. We can then say that having more observers leads to stronger beliefs.
That's simple enough to see, but there aren't always gonna be convenient observers like that. Observers can be created, though. It should be plain enough to understand how a half-man like the mole men can count towards observation. But illusions can perform this task as well. The illusions can also be entirely internal and mundanely psychological.
If I create a mental model that's really robust, like an imaginary friend, they can count as an observer easily because it's easy to get mental models to affirm your beliefs. A mental model isn't going to be as convincing as a real living observer, but it's enough for a little extra conviction.
To see it become a useful process, you just need a more elaborate example: say I believe I can shoot lasers from my eyes. Now say I have 100 squirrels paralyzed and forced to watch a specific location. I go to the location get a huge boost of affirmation if I successfully perform the feat (or rather, if I believe I convinced the squirrels...), and now I have really strong eye lasers. [there are systems in place to prevent this from happening on a large scale, but the explanation will have to wait for a future section]
7_stains
There's an additional factor to the range of conviction that CE fields have: stains. Put simply, every subjective reality leaves a sort of residue of conviction on objective reality. Previously, I mentioned that beliefs can cause instant distortions, and that fiction made real can return to fiction in the absence of belief. What I didn't mention was that the loss of reality on a fiction is gradual if there's no belief pushing the transition.
Consider an isolated village where oranges are believed to be blue. That village is wiped out by some disaster. Years later, an expedition group enters the territory of that village and finds blue oranges. They'll be a bit confused, but likely accept that it's just a weird breed of orange, which updates the fiction while preserving the prior trait of "oranges are blue". The exact time it would take in isolation for those oranges to become orange again is hard to calculate, but it's a factor of how strongly that village believed it. The change from blue to orange isn't instant, again, so even just the passage of a month (after the village is wiped out) will result in oranges that are slightly less blue. Eventually, that "stain" will be gone - as long as no one reinforces it.
This isn't limited to coherent beliefs. Strong emotions and memories also leave stains. Semantic quibbling, I guess - you could say those things hold conviction as well.
Some settings will have a sort of janitor crew to handle the stains. It helps stabilize the chaos of how reality works. Personally, I often put magic monsters in that role because it's a good excuse to bring in alien psychology and to generate easy thematic control. But not every setting should be like that; some will have other types of natural stain processing - you can think of it like a sort of immune system of objective reality. And settings that don't have that sort of system will have other things going on because of the stain buildups. I'm not really here to detail specific settings, though.
To be clear, even if the stains are instantly wiped clean, it won't amount to much difference if it's immediately influenced to go back the way it was by a CE field. Like trying to keep your hands dry while swimming, you'll technically have rapid fluctuations, but it's wasted effort that amounts to nothing.
It's not always as simple as the above example with the oranges, of course. Since CE fields aren't exactly a real 3d zone, there can be blind spots nearby and focus spots across the world. The belief could be contrived to be that the blue color indicates ripeness of an orange, or that while non-blue oranges exist elsewhere, the special blue ones have potent medicinal properties. These beliefs would have less conflict with the stronger beliefs of others about oranges, and allow a better chance of stain combination. Like trying to mix fluids, you aren't gonna get oil to stabilize together with water - you need to minimize contradictions and there's priority given to older stains. This is to sort of explain how reality sorts out what can be "true", even though there's no conscious will behind the process.
Stains always occur at the physical epicenter of a CE field, even if the same stain happens elsewhere. Example: belief that the moon is a monster. The moon itself receives stains (to a degree...), but the believer leaves a stain containing that belief everywhere they go. Only the direct stain on the moon can directly influence the reality of the moon. This is important to mention because stains are perceptible via CE fields, even if the individual doesn't understand the data they're getting. In practice, if that believer is just some crazy vagrant, then if you sleep in a place he slept the night before, you'll probably have a dream about the moon being a monster, or at least be more open to that idea - even if you simply dismiss it as a weird thought.
I should have mentioned this in an earlier section, but it's hard to stain things that exist in a state of fluctuation. This is because it depends on how the believer conceptualizes the thing. Like, let's say a river. How do you conceptualize that river? Is it the water flowing through it, the specific space covered by the water, a specific mental snapshot of the river, etc. All of those allow for different types of staining. If the river is conceptualized as the water flowing through it, then the river ceases to exist according to the stain if the water flow is cut off. If the river is conceptualized as the specific space covered by the water, then completely freezing over still allows it to continue existing and if you pick up mud from it it will count as the river being in your hand. If the river is conceptualized as the specific mental snapshot of the river, then it immediately stops existing except as an echo of the past, because all of that specific water has left the area of the image.
