You do not know ghosts do not exist in the same way you know a 1000 foot tall elephant does not exist, or that you know what a sandwich is, or that water is good for you to drink, or that the sky looks blue, or any number of a million other things that we know from direct experience or logic.
I suppose you might say you know that Jupiter is a planet in our solar system in the same way you know ghosts do not exist, since both beliefs are generally supported by science and not verifiable for yourself. Then again you can get a telescope and look at Jupiter in the night sky sometimes. Of course that doesn’t prove it is really what science says it is or that their knowledge is infallible about it.
You at least admit that ghosts could be real. Your standard is to believe whatever science is saying in terms of consensus. How many scientists do you think believe in the existence of ghosts? It is more than zero. But consensus, as long as the majority say something you will align yourself to it. That leaves a person vulnerable to when the consensus is wrong, or strongly motivated to cover up certain things.
If most scientific funding comes from the government directly or indirectly, and there are certain outcomes of research that are praised and rewarded while others are discouraged or disparaged and can lead to the loss of your funding and your loss of respect in your field, do you think that acts as a powerful motivator and incentive structure affecting research results and who gets published? If you admit to this, how do you personally deal with this fact when it comes to you blindly believing in scientific consensus?
For myself, I don’t really care about the scientific consensus so much as I trust my own beliefs and logic and experiences. Those are number 1 for me, scientific consensus is number 2 at best. The issue of ghosts is interesting because it is not some little fringe thing, like asking how many people have seen unicorns in their life. While the answer to that is non-zero too, and would be interesting to follow up about, the issue of ghosts is orders of magnitude greater. We are talking about significant percentages of the human population across the entire planet. Going back throughout history. Across cultures and religions and races and age and belief systems. You are comfortable dismissing all of that because scientific consensus says it is not true, that is up to you. I am not comfortable dismissing it. So just like with the case of Jupiter, which I fully acknowledge might not exist or might exist differently than what science tells us, I also acknowledge ghosts might be real. Do I know they are real? No. Do I believe they are real? Yes I think it is more likely than not that something about ghosts is real, although we probably do not understand it very well.
In terms of reasons why ghosts and experiencing them might not be more common, here are a few reasons. Remember that each one of these by itself acts as a reason or cause to dismiss the experience, so adding all of these up together means the burden of going from “people are experiencing ghosts” to “you hear about it in a way that is validating and makes sense to you personally as being true” is almost impossible to happen even if ghosts are actually real and some people really are experiencing them:
(Hint, this thought experiment requires you to assume for the sake of argument that ghosts are in fact real and that some people do in fact experience ghosts for real),
Physical limitations: if ghosts are real, they are probably somewhat rare to experience. Whatever causes a ghost to appear to us is something dependent on combination of unlikely causes, and seems to occur only for brief moments of time. Additional physical limitation is that ghosts seem to be somewhat averse to being recorded by electronic instruments such as cameras, although EVPs may have more luck. But in any case it is physically more difficult to record a ghost than it is to record normal physical objects.
Mental bias: the mind tends to dismiss things that are far outside of its comprehension. Even if you did experience a ghost, your brain would probably try to refuse to see or acknowledge it, or later you would likely believe it was a hallucination or dream.
Social bias: if you tell someone you saw a ghost, most of them will laugh at you or think you are crazy or stupid. Just like how you insulted everyone who believes they saw a ghost as “low IQ”, that dismissive insulting attitude is commonplace. This acts as another reason why, even if someone did experience a ghost for real, they are not likely to talk about it.
Media bias: even if someone overcomes the previous three limitations and talks about their experience of seeing a ghost, media publications and news are not going to report it or will report on it only in a short and often dismissive way.
Scientific bias: the scientific community is not going to take this seriously. If a scientist does a study that seems to give evidence for ghosts, the rest of the scientific establishment will dismiss it out of hand and that scientist may lose his reputation, funding or position. Adding in the physical limitations from the first point here, this adds another layer of difficulty with replicating results, which is exacerbated because the amount of research being done in this area is very very small to begin with.
Government bias: even if scientists managed to produce convincing research about the existence of ghosts, it is likely the government would act to suppress or ban this from public knowledge. Paranormal or psychic phenomenon would be considered, if believed to be true, something inherently powerful and needing to be controlled and managed by the authorities. They do not want people believing in crazy things that make them harder to control, and the government also acts to limit what we know of in reality. There are tons of examples of the government covering up research, think what they did to Tesla’s research when he died. If the government realized ghosts were real they would most likely do their best to cover this up from the public and study it in secret for their own purposes.
You would need to pass through each one of those limits, and consistently over time for large numbers of people, to finally have a situation where someone like you would live in a world where it makes sense for you to admit to the existence of ghosts. The scientific consensus, media, government, social attitudes, and physical limitations would all need to be on your side. But instead, they are all against you. It makes sense why you do not believe in ghosts, especially since you have seemingly not experienced a ghost for yourself.
For me, I am open minded enough to understand the logic of the setup and situation. I combine the layers of barriers or limits I just explained, with the fact that these are multiplicative and not merely additive (all of the limits would need to be overcome for ghosts to become reasonably believed in by you), along with the sheer huge number of people who had these experiences and the consistency of many of the experiences, and combine that with many of the personal first hand reports I have heard or read about people experiencing ghosts seem very believable and cannot easily be dismissed by appealing to hallucination, drugs or other factors like that.
I also think the idea of ghosts makes logical sense. At least it is not logically impossible, and it seems absurd to me to believe there is nothing after death and nothing at all to anything spiritual or non-physical, as if everything we see or measure with our material instruments is all that exists. Like with the electromagnetic spectrum we experience just a small area of it. Reality does not need to limit itself to our perceptions or beliefs, and in fact many people have reported seeing ghosts anyway so the argument could be that it is foolish to automatically dismiss that out of hand by calling all of those people liars or crazy.
That is the basis for my view. I take all of the above points together and come to the objective, unbias conclusion that ghosts could certainly be real and in fact based on the totality of all of the above points taken together it seems likely to me that something exists which is what people call ghosts. I don’t know what that thing is, I don’t even know that it really does exist. But I am not prepared to claim knowledge that it does not exist, because that would require me to dismiss all of the above points and call every single person who says they saw a ghost either a liar or crazy. Which I am not prepared to do. I have no personal motivation to align with the scientific community nor to believe it should be followed unquestioningly, I have seen too many examples of its errors and its biases, shady practices stemming from improper incentives and funding needs. Money runs modern science, the big doners and big institutions and big government control the purse strings and so they will tend to get the results they want.
I will believe what scientific consensus says when it makes sense to me and when I do not see a lot of institutional bias and reasons why that consensus might be manipulated or incentivized in a certain direction.
And you might be surprised there are a lot of scientists who do believe in ghosts, and who are still doing and reviewing research into the subject:
https://www.spr.ac.uk/publicationsrecordingswebevents/recordings-spr-events-audio-video
Of course they may not be comfortable sharing their results with everyone, because they happen to live in a world and climate that is made up of people like you. People who will dismiss and mock them before taking the time and patience and neutrality to think about and look at the idea seriously. Which again is not me saying that I know they are right. But it is me saying that you and people like you are a barrier to this knowledge being widely accepted and known if indeed it does happen to be true.