"Metaphysicians want to know what the world is like, and tend to ask questions about what sorts of things exist (e.g. are there numbers?), as well as what sorts of things are fundamental (e.g. is everything made of simple elements?). "

https://philpapers.org/browse/metaphysics

David Lewis:

"I believe, and so do you, that things could have been different in countless ways. Ordinary language permits the paraphrase: there are many ways things could have been besides the way they actually are. I believe that things could have been different in countless ways; I therefore believe in the existence of entities that might be called ‘ways things could have been.’ I prefer to call them ‘possible worlds.’ (1973a: 84)

https://plato.stanford.edu/entries/david-lewis/

Here's the first article I've seen that discusses the possibility of determining whether alternate universes might exist. It still seems a reach.

In mathematics, a dynamical system might proceed to evolve along alternate paths at points of bifurcation. But what happens in math may be mere fiction in the physical world.

Here's the first article I've seen that discusses the possibility of determining whether alternate universes might exist. It still seems a reach.

In mathematics, a dynamical system might proceed to evolve along alternate paths at points of bifurcation. But what happens in math may be mere fiction in the physical world. — jgill

The idea of the multiverse is what I think possible worlds refers to. There is no universe, just multiple universes.

"Metaphysicians want to know what the world is like, and tend to ask questions about what sorts of things exist (e.g. are there numbers?), as well as what sorts of things are fundamental [nature of reality] (e.g. is everything made of simple elements?). "

https://philpapers.org/browse/metaphysics — Jackson

:up: Nice!

I think that metaphysics, whatever meaning you give to it, has the defect of being bound to being: in certain contexts it is almost a synonim of ontology. The consequence of being bound to being is that it ignores time and subjectivity. Along history metaphysics was criticized by historicists, because, by trying to understand how things are, it looses sight of the fact that things, rather than being, are becoming (Heraclitus). As a consequence, about any metaphysical system of ideas, we should never forget that it is itself conditioned by its own being immersed in the flowing of becoming, changing.
The problem raised by subjectivity is similar, because the fact that anything we think of is conditioned by our subjectivity makes our thoughts dependent on the variability, unreliability of subjectivity.
In other words, the defect of metaphysics is its intention to reach a system of ideas that is expected to be stable, definitive, ultimate, objective, reliable, solid.
We can mean metaphysics in a more flexible and humble perspective, but in this case it seems to me that what we are doing is not philosophy, but science. When science makes its hypotheses, it doesn’t build them with the intention of reaching an end to research. On the contrary, science makes hypotheses as simple intruments to acquire better and better knowledge of the world, without any intention to stop.
So, I would say: if you suppose, for example, that the moon is a planet, just to see how this idea works in comparison to the results coming from observation through technical instruments, then “the moon is a planet” is a scientific hypothesis, which means, there is no intention to make it the ultimate, fundamental system of ideas about the moon.
If you say “the moon is a planet” with the intention to build an assertion that should resist to any criticism, any objection, any doubt, so that, if different conclusions come from observation, we should think that most probably observation is wrong, then you are trying to build metaphysics.
If we think that 2+2=4 is an eternal truth, indesctructible, unassailable, impossible to question, then you are thinking of it in a metaphysical way. As such, this kind of thought has the defect that not only tomorrow 2+2 might give a different result, but also our thoughts about it might change, because ideas are subject to time, change, becoming, as well as anything else.
This way, any attempt to build a system of ideas, with the intention to reach something stable, is metaphysics. So, even when I say that everything is subject to change, if I treat this assertion as a stable and permanent theory, I am doing metaphysics as well.

I think that metaphysics, whatever meaning you give to it, has the defect of being bound to being: in certain contexts it is almost a synonim of ontology. The consequence of being bound to being is that it ignores time and subjectivity. — Angelo Cannata

I do not think that is true.

Along history metaphysics was criticized by historicists, because, by trying to understand how things are, it looses sight of the fact that things, rather than being, are becoming (Heraclitus). — Angelo Cannata

And that is doing metaphysics.

Any statement about how the world is, is metaphysics. Say, here are the limits of knowledge, is metaphysics.

In other words, it seems to me that metaphysics just lack self-criticism.

In other words, it seems to me that metaphysics just lack self-criticism. — Angelo Cannata

Can you give an example? I mean, lots of philosophers publish papers on metaphysics and criticize each other.

Here's the first article I've seen that discusses the possibility of determining whether alternate universes might exist. It still seems a reach.

In mathematics, a dynamical system might proceed to evolve along alternate paths at points of bifurcation. But what happens in math may be mere fiction in the physical world. — jgill

The idea of the multiverse is what I think possible worlds refers to. There is no universe, just multiple universes. — Jackson

In my understanding, possible worlds are different from the multiverse. Possible worlds are metaphysical entities while the multiverse is, at least purportedly, science. It is also my understanding that neither possible worlds nor a multiverse associated with quantum mechanics are even theoretically observable. A multiverse associated with cosmic inflation may be.

In my understanding, possible worlds are different from the multiverse. Possible worlds are metaphysical entities while the multiverse is, at least purportedly, science. It is also my understanding that neither possible worlds nor a multiverse associated with quantum mechanics are even theoretically observable. A multiverse associated with cosmic inflation may be. — T Clark

A possible world is a logical structure, so a multiverse would qualify.

Since the very beginning they could have used better self-criticism. Think about Aristotle, for example: why didn’t he ask himself “Why should things be the way I am describing them, matter and shape?”. Plato as well: it is strange that, in the cave myth, he didn’t realize that the one who looks outside the cave is in the same conditions of the ones inside it: every position is conditioned by itself. And Descartes: how is it possible that he didn’t realize that his assumption “I think, then I am” was so highly exposed to criticism? We can even notice that already at their time there were people criticizing their thoughts: think about the sofists, for example. Aristotle knew the problem raised by the sophists; nonetheless, he just carried on, with the result that his philosophy is easy to be demolished. I even think about Heidegger: he criticized the traditional ideas about being, but he also talked about “authenticity”: how didn’t he realize that this concept is extremely similar to the idea of “truth”, which is again exposed to his very own criticism, just on a different level? The simple question that most of them, surprisingly, ignored, is: why should things be just the way I am thinking they are?

A possible world is a logical structure, so a multiverse would qualify. — Jackson

From what I've seen, multiverses are proposed as physically existent entities, not logical ones. If a parallel universe is not physically observable, one of three conditions apply 1) It is metaphysics and useful, 2) It is metaphysics and not useful, or 3) It is meaningless. In my understanding, multiverses associated with quantum mechanics are not even theoretically observable.

From what I've seen, multiverses are proposed as physically existent entities, not logical ones. If a parallel universe is not physically observable, one of three conditions apply 1) It is metaphysics and useful, 2) It is metaphysics and not useful, or 3) It is meaningless. In my understanding, multiverses associated with quantum mechanics are not even theoretically observable. — T Clark

I don't agree. But I am not an expert on physics and cannot cite current research. That said, a parallel universe is not part of multiverse theory. I think of it this way. If we say there is one universe we have to explain why there is nothing which unifies that reference other than 'all that exists.'

I don't agree. — Jackson

You don't agree that multiverses are proposed as physically existent entities or you don't agree with my exposition on metaphysics?

If we say there is one universe we have to explain why there is nothing which unifies that reference other than 'all that exists.' — Jackson

Are you saying that the universe/multiverse distinction is only one of language? I don't think that's what you're saying. Let's define "universe" as everything that is or previously was observable, at least in theory.

Are you saying that the universe/multiverse distinction is only one of language? I don't think that's what you're saying. Let's define "universe" as everything that is or previously was observable, at least in theory. — T Clark

Right, I am saying that is an indeterminate reference.

My interest is Leibniz's concept of possible worlds. Now, at 'time' (event) of the Big Bang, life on planet earth was possible even though there was no planet. So it is a possible world.

So, I would say: if you suppose, for example, that the moon is a planet, just to see how this idea works in comparison to the results coming from observation through technical instruments, then “the moon is a planet” is a scientific hypothesis, which means, there is no intention to make it the ultimate, fundamental system of ideas about the moon.
If you say “the moon is a planet” with the intention to build an assertion that should resist to any criticism, any objection, any doubt, so that, if different conclusions come from observation, we should think that most probably observation is wrong, then you are trying to build metaphysics. — Angelo Cannata

As a scientist , one understands the meaning of ‘moon’and ‘planet’ in relation to an overarching theoretical orientation than offers a predictive astronomical account. One’s
technical instruments, how they are used to observe and measure, contribute to the production of the theoretical orientation itself. Even as ‘there is no intention to make it the ultimate, fundamental system of ideas about the moon”, the wider metaphysical assumptions informing the general aasumptions concerning the moon and its connection with astronomical theory is left unexamined by that science. No amount of openness to disconfirmation via evidence will by itself alter that overarching metaphysics to the extent the scientist is not aware of the fact that observation and disconfirming evidence are moves within the frame. Changing the frame is not simply a matter of being beholden to evidential results from
one’s measuring instruments, since those instruments are themselves expressions of the frame.

I think it is good to clarify the following things.

The aim of metaphysics is to go beyond physics, beyond science, to get some stable, unassailable truth, that must be impossible to reach by science. If it is possible to reach it by science, then it is subject to all the changes that science is able to bring, like new discoveries, new instruments, new evidence. As such, it is not metaphysics, it is science.
So, if we realize that “the moon is a planet” is something that can be proved or disproved by science, then it is not a metaphysical truth.
An example of truth not reachable by science is this one: the ultimate meaning of the world is to be an instrument to make humans happy. Or: the world was created by God. The purpose of these statements is to reach levels of knowledge that science is unable to reach. This way, metaphysicians feel that they have found a remedy to two problems of science: 1) what science says is changeable by new discoveries; as such, it is not stable, it has not the absolute reliability of eternal truths; 2) science is unable to give us any knowledge about transcendent things, like God, meaning of existence, spirit, interpretation of life.

Science can deal with metaphysical concepts, but when these concepts are dealt with by science, the aim of research about them is not to find anything stable: science has no interest in finding stable things; science has interest in making research based of measurable evidence. So, for example, science can be interested in dealing with the meaning of human existence, insofar as it is possible to find in this question some measurable elements, like, for example, statistics, history, geography. In this context, science is not interested in finding a meaning of existence that must be the ultimate, the definitive one.

After having clarified these things, we can go on by exploring how weak or strong metaphysics is.

The aim of metaphysics is to go beyond physics, beyond science — Angelo Cannata

That is just not true.

I am interested in seeing how it is not true, according to what philosophers.

I am interested in seeing how it is not true, according to what philosophers. — Angelo Cannata

What articles or books in metaphysics are you referring to?

The aim of metaphysics is to go beyond physics, beyond science
— Angelo Cannata

That is just not true. — Jackson

Sounds reasonable to me. How about this?

“In seeking a comprehensive account of everything, metaphysics is continuous with science, going beyond particular scientific theories.”
(Metaphysics of science between metaphysics and science, Michael Esfeld)

“In seeking a comprehensive account of everything, metaphysics is continuous with science, going beyond particular scientific theories.”
(Metaphysics of science between metaphysics and science, Michael Esfeld) — Joshs

Sorry, did not understand that. Why does metaphysics have to be about science?

You can have a look here, as an example.

You can have a look here, as an example. — Angelo Cannata

I know this roils some, but Wiki is not a good source for philosophy.

Anything can be not good for anyone. Can you say any source that is good for you and shows that what I said is wrong?

Many scholars say Aristotle did not name his text "Metaphysics." Or that it simply referred to what he wrote after the Physics.
In the Metaphysics Aristotle describes the project as "first philosophy." Or, analysis of basic concepts.