Thought experiments (Gedankenexperimenten) are "facts" in the sense that they have a "real life" counterpart in the form of electrochemical activity in the brain. But it is clear that they have nothing to do with facts "out there." These things are not true.
But are they not true because they don't have anything to do with facts? What is the link between Truth and Fact?
One answer is that Truth has to do with the chance that something will happen. If true, it must happen, but if false, it can't happen. This is a world where everything is either good or bad. Must all possible events occur? Of course not. Would they still be true if they didn't happen? Does a true statement have to make sense in the real world?
From what you know, the answer is yes. We can't think of a thought that doesn't involve brainwaves. A statement that stays just a possibility seems to live in the middle ground between true and false. It's only true when it comes to be, when it happens, when it matches up with real life. If we could show that it would never happen, we would have had a good reason to call it false. This is the result of Aristotelian logic that has been used for thousands of years. Logical statements talk about the world, so a statement is not true if it can't be shown to have a direct connection to the world.
This approach, on the other hand, is based on some assumptions:
First, that the world has a beginning and an end. Saying that something that didn't happen can't be true is the same as saying that it won't happen (i.e., to say that time and space - the world - are finite and are about to end momentarily).
Second, people think that truth and falsehood can't go together. This one has been dead for a long time thanks to quantum and fuzzy logic. There are true and false things that happen in the real world. A particle can "be" in more than one place at once. This fuzzy logic doesn't make sense with what we know, but if there's one thing we've learned from physics in the last 70 years, it's that the world doesn't make sense with what we know.
The third idea is that the spiritual world is just a part of the physical world. We are like membranes with holes of a certain size. We focus on well-defined types of experiences, have limited (and evolutionarily biassed) senses, and are programmed in a way that tends to keep us alive until we die. We are not just outsiders looking in. In fact, the very idea of an observer is a matter of debate, as both modern physics and Eastern philosophy have shown.
Imagine that a crazy scientist has found a way to put a strong hallucinogen into all the water in the world. At a certain time, everyone on Earth sees a huge flying saucer. What about this saucer can we say? Is it true? Is it true?
There's a good chance that the saucer doesn't exist. But who says that? If this statement isn't made, does that mean it doesn't exist and isn't true? In this case (of the fake flying saucer), the thing that isn't said is true and the thing that is said by millions of people is obviously false.
Still, you could make the case that the flying saucer was real, but only in the minds of the people who drank the tainted water. What kind of being is this? What does it mean to say that a hallucination "exists"? The psychophysical problem is that there is no way to prove that a thought causes the brainwaves that go along with it in the real world. Also, this leads to an endless cycle of going backwards. If the brainwaves caused the thought, then who made the brainwaves? In other words, who (or maybe what) is thinking?
The subject is so complicated that it would be a guess to say that the mental is just a part of the material.
So, it's best to keep the ontological and the epistemological separate. But what's what? Epistemologically and statistically, facts are determined by aware and smart observers. Their "existence" is based on good ways of knowing. But we assume that even if there are no observers, facts will still exist and won't lose their "factuality," which is their real-life quality that doesn't change depending on who is looking at them.
How about the truth? It's clear that it's built on solid ontological ground. Something is true or it isn't, and that's the end of it. But then we realised that truth is a matter of the mind and can be affected by things like hallucinations. Also, the blurring of lines in quantum and other non-Aristotelian logics suggests either that true and false are only "in our heads" (epistemological) or that something is wrong with how we interpret the world, our exegetical mechanism (brain). If the latter is true, then the world does have true and false values that contradict each other, but the organ that helps us figure out what is true and what is false (the brain) has gone wrong. The paradox is that the second method also assumes that at least being able to tell the difference between true and false values depends on an epistemological detection device.
Can we think that something is both true and not true? Of course it can (remember "Rashomon"). Could it be the other way around? It can, yes. We call these things "visual or sensory illusions." Even the feeling of solidity is a trick of our senses. There are no such things as solid objects. (Remember the physicist's desk, which is 99.99999 percent vacuum with tiny granules of matter floating around.)
To bring these two ideas together, we have to let go of the old (and probably important to our sanity) idea that we can know everything about the world. We probably can't, and that's why we don't know what to do. There may be both "true" and "false" things in the world. It could be true that truth is what exists and lies are what don't. We will never know, though, because we can't know anything about the world as it is.
But we have everything we need to know about what's going on in our heads. There, the images of the real world start to take shape. We are used to these representations (concepts, images, symbols, and language in general) and mistake them for the world itself. Since we can't directly know the world (without the help of our interpretive tools), we can't tell when a certain representation corresponds to an event that is independent of who is looking at it and stays the same no matter who is looking at it. When we see an image, it could be the result of interacting with light outside of us (which is "real"), or it could be the result of a dream, a drug-induced illusion, fatigue, or any other number of brain events that have nothing to do with the real world. These are things that depend on who is looking at them, and if enough people agree, they are considered to be true or "to have happened" (e.g., religious miracles).
It doesn't make sense to ask if something is true or not unless it has to do with our internal world and our ability to observe. When we say "true," we mean "exists," "existed," or "will almost certainly exist" (the sun will rise tomorrow). But the only way to know if something exists is to think about it. So, truth is nothing more than a state of mind. Whether or not something exists can be seen and measured (the outside and the inside, the real and the mental). This gives a picture of the world that may be close to reality, but it may also be far from it.
