memes

This is just an identity paradox, which the literature is full of them, and I find Plato's solution way less convincing than the holistic solutions presented by people like Engels and Bohm.

The holistic solution is to argue that "identity" really doesn't exist. There was never a "river" to begin with. Reality is just not actually divided up into autonomous objects. As Bohm argued, autonomous objects are human inventions. We create them because talking about reality as a whole, all at once, is not physically possible with our finite brains. We have to break it up into chunks to talk about it, and it is a mistake to confuse those chunks for reality, as if reality really contains autonomous objects moving around within it.

This was something Engels also cautioned against, outright rejecting identity for a simple reason. Imagine you say that this particular tree is represented by the variable A. Well, the moment you have said the tree is A, the tree has already changed a bit, it's not what it was before, so it is now ¬A. If you say both A and ¬A are the same, that's logically inconsistent. If you say the tree at the instantaneously later time should be considered a different variable B, then you no longer have a single "tree" but an infinite number of distinct objects, which contradicts with the notion of there being a single tree.

Indeed, he points to many other problems, such as the fact that you cannot meaningfully draw a concrete border for where the tree begins in space and where it ends, and where it begins in time (when it was "born") and when it ends (when it dies). If you zoom in closely enough, the border between the "tree" and everything else becomes fuzzy and ill-defined, and its transition from a seed to a tree, and from a tree back to the earth, also is a gradual process without a well-defined boundary. Engels thus concludes that for formal logic to make sense at all, we intentionally have to ignore the real complexity of the world. If we say the tree is A, for example, we have to first ignore the flow of time and treat it completely static, and we have to not zoom in too closely so that we don't notice the issue with ill-defined borders, so on and so forth.

The conclusion is, again, that objects don't really exist. There is no "tree" or "river" that is a well-defined, static and unchanging object like the variables in formal logic, A or B or X or Z. This is where your Plato point breaks down. You replace the ill-defined river with another definition including an ill-defined "shape of the landscape," which is also changing all the time just as much as the river does, with no singular and consistent "shape of the landscape," and its very precise shape is impossible to rigorously define even at a single time instant.

Although, the philosopher Jocelyn Benoist, who does take a similar approach, disagrees with the framing of saying that "objects don't exist," because a philosophy that just says no thing exists can be linguistically confusing, so there should be some meaningful way to refer to the existence of real objects.

He makes a distinction between abstract objects, which do not exist in reality and are only a human construct part of our language, and real objects, which is when the linguistic symbol is employed in a Wittgensteinian language game, and thus is imbued with a context.

For example, Benoist would say that, if you are talking about a river in the abstract, it does not refer to anything real. But the word "river" serves as a socially constructed norm that can be used to judge reality to be something, and thus can be employed in a social setting. If I see a river and point to it, and say, "look at that river over there," the river is now not just an abstract symbol, but it is a symbol pointing to something in a real world context, where people can really observe its glistening surface, dip their toes in it and feel its cold water, etc.

It's meaningful to talk about real objects only if we are implicitly or explicitly imbuing that object (as a symbol) with a real-world context (where the symbol is employed to identify something in real-world experience) through the social practice of identification, which is the purpose of objects, to serve as a norm by which to judge reality by. The real object is thus the object + the context in which it is employed.

You missed the part where metaphysicians claim that what they are doing isn't metaphysics at all, but science and logic, or something along those lines.

No, I didn't. I agree with that. I have literally written an entire book criticizing how people conflate the mathematical models of modern physics with philosophical interpretations of those models, and then pretend their metaphysics is not philosophy but something "proved by the empirical evidence."

The book was motivated precisely by the question I raised in my previous comment: does the common man's position really have to be abandoned?

Philosophers, including physicists who write philosophy, very commonly point to modern physics as establishing the need to abandon certain common worldviews and adopt a new metaphysics. But they often present this not as metaphysics, but as something directly established by empirical reality, such that questioning it is treated as equivalent to denying science.

One example is the dominant interpretation of special relativity, which claims that space and time are ontologically relative. We can experimentally verify that clocks drift from one another exactly as the mathematics predicts, such as when two airplanes fly in opposite directions and meet again. The conclusion is then presented as empirically proven: space and time themselves must be relative.

But John Bell pointed out in "How to Teach Special Relativity" that the same mathematics can be given a different philosophical interpretation while preserving the same empirical predictions.

You can instead assume that spacetime is absolute, while objects in motion undergo physical effects that cause moving clocks to slow and rulers in the direction of motion to contract. The measurements of rods and clocks would then be emergent properties produced by absolute space and time plus these physical effects. The mathematics remains the same, but its ontological interpretation changes.

If physicists object that such an absolute rest frame could never be experimentally identified, that does not prove it does not exist. It means only that its existence is empirically undetermined. At that point, the usual response is Occam's razor: if we cannot directly detect such a frame, we should eliminate it from our ontology.

My point is not that this is wrong. It may be a perfectly reasonable philosophical choice. My point is that Occam's razor is a philosophical argument.

You have not empirically proven that space and time are relative. You have shown that relativity follows from the mathematics given a particular interpretation of what the mathematics represents. Choosing that interpretation over another requires an additional philosophical argument. If there were motivation to make an argument in response (which is a whole other topic, but I argue one can mount a strong counterargument), then it would lead to a philosophical debate, and that debate could not be settled empirically.

This is the broader point I am making: the same mathematics can be compatible with multiple ontological interpretations. Empirical evidence can constrain those interpretations, but it does not necessarily determine them uniquely.

So, if you are an extremely conservative skeptic who refuses to abandon the common man's worldview unless doing so is strictly necessary, you can always ask whether the new worldview actually follows necessarily from the mathematics and empirical evidence.

Often, it doesn't. The physical evidence motivates the metaphysical debate, but it does not wholly determine its outcome.