I would define metaphysics as follows: anything left over that won't be explained by more rigorous fields. To the extent that it has value, the field of being and content has been removed from metaphysics by physics, phenomonology, etc. To the extent that it has value, the field of causation and origins has been stolen by science generally and cosmology and evolutionary biology in particular. To the extent that they have value, the constants of nature have been annexed by physics. If any idea in metaphysics is found to have any value, it ceases to be metaphysics and becomes something else. Metaphysics is then all of the ideas that will never be found to have any value. I'd put them in the following groups:

Metaphysics of the gaps: This Kantian metaphysics relies on things being unknown, such as having an incomplete picture of how mind arises from physical constituents and processes.
Metaphysics of the unfalsifiable: This relies on the outside chance that an unjustifiable idea might be true, such as the existence of God.

Metaphysics of ignorance: This relies on the metaphysician not knowing or pretending to not know how something is so they can continue on the basis that it is not, such as the evolution of species or the arrow of time (although some metaphysical questions regarding the arrow of time fall under MotG). The difference between this and MotG is that the latter claims justification via the gaps, whereas this tends to insist on purely metaphysical (i.e. not useful) approaches to well-understood problems.
Metaphysics of the impossible: This relies on considering only scenarios that are logically impossible or factually untrue, such as the "do otherwise" scenario of anti-determinist free will formulations.

You can do metaphysics then by picking one of the above, say: that the root cause of the creation of the universe is unknown. Despite the fact that everything we do know about the start of the universe comes from astronomy, cosmology, particle physics and the like, the next step is to disregard all of this and insist on a completely useless framework for understanding how it might occur. When asked to justify the framework, you can do so in any of the above four ways: claim that there is no hard evidence for an alternative solution; claim that your solution cannot be disproven; claim that any reference to non-metaphysical knowledge is out of scope, inferior, or invalid for epistemological reasons; and finally claim that anything that follows from your proposal that seems invalid doesn't matter because it's ab initio, therefore independent of how things are or can be in reality. — Kenosha Kid

via Jose Benardete, I think the most concise definition of metaphysics I know - at least in it's classical guise:

"Metaphysics in its classic sense has always been understood to be the rational investigation of the eternal order. Central to that investigation is the distinction between that which is eternal and that which is perishable, and though metaphysics addresses itself to both of those grades of being, its primary concern lies with the eternal, so that if there is nothing eternal, or if nothing eternal can be known, then metaphysics is an impossibility. The distinction between the eternal and the perishable may be said to be a cosmological one, in that the concept of time is cardinal to it.

That distinction may be translated into what might be styled ontological terms, as a distinction between the necessary and the contingent. What is eternal must also be necessary, and in this sense metaphysics is the science of being qua being, or of being as such, or of being insofar as it is necessary. If there is nothing which is necessary, or if nothing necessary can be known, then metaphysics is impossible." ("The Analytic A Posteriori and the Foundations of Metaphysics") — StreetlightX

Meta-physics :
The branch of philosophy that examines the nature of reality, including the relationship between mind and matter, substance and attribute, fact and value.
1. Often dismissed by materialists as idle speculation on topics not amenable to empirical proof.
2. Aristotle divided his treatise on science into two parts. The world as-known-via-the-senses was labeled “physics” - what we call "Science" today. And the world as-known-by-the-mind, by reason, was labeled “metaphysics” - what we now call "Philosophy" .
3. Plato called the unseen world that hides behind the physical façade: “Ideal” as opposed to Real. For him, Ideal “forms” (concepts) were prior-to the Real “substance” (matter).
4. Physics refers to the things we perceive with the eye of the body. Meta-physics refers to the things we conceive with the eye of the mind. Meta-physics includes the properties, and qualities, and functions that make a thing what it is. Matter is just the clay from which a thing is made. Meta-physics is the design (form, purpose); physics is the product (shape, action). The act of creation brings an ideal design into actual existence. The design concept is the “formal” cause of the thing designed.
5. I use a hyphen in the spelling to indicate that I am not talking about Ghosts and Magic, but about Ontology (science of being). — Gnomon

"Ontology" is a word often used here and elsewhere. What does it mean? This from online, "Branch of metaphysics concerned with identifying, in the most general terms, the kinds of things that actually exist." The more I think about this definition the less I understand it. And implied is that it is a species of, metaphysics. These are often referred to as sciences, but that doesn't seem right: what would they be sciences of?

Two words, then: metaphysics and ontology. Metaphysics, from online: "Branch of philosophy concerned with providing a comprehensive account of the most general features of reality as a whole; the study of being as such."

Ontology comes from the Greek ῶν (on), being, and λόγος (logos), knowledge.

It's well known that Metaphysics is also the name of an Aristotelian treatise, and almost as well known that the title, Metaphysics, says nothing about the contents of the treatise, not being Aristotle's title, it having been applied long afterwards and meaning "the books after the Physics."

And this thread is not about Aristotle's Metaphysics specifically. It is about what we understand now or can or should understand now about these words. If Aristotle speaks to that, then that's welcome. But in that case what he says is a matter of fact and the question goes to relevance. The distinction is that in one sense, while Metaphysics is the non-committal title of an ancient book, metaphysics is a modern name. Of what, exactly, I'm hoping I'll learn as this thread develops.

I'm hoping that certain difficulties with the two words will become apparent and that we can quickly dismantle problematic definitions. What, then, we end up with I'm curious to see.

Both seem concerned with "the most general terms" and "the most general features." Being and existence are the two most general terms, and I am not even sure what a "general" feature is. So we can say of something that exists, that it is. And no doubt much more, but everything else, it seems to me, devolves to non-general predicates. And of being itself, what predicates does that have?

Ontology seems self-limited, then, to the proposition that being is - and no more than that can be said. And metaphysics, pending a good definition for a "general" feature, seems about in the same circumstance. That is, that they're both empty - almost empty - concepts. At least as defined above. Is that the final word? — tim wood

In recent discussions, it has become clear to me that I have no clear idea of what metaphysics is. So I've come here, to ask the experts.... :wink: Seriously, can we have a stab here at defining and describing metaphysics? Does it have, as I suspect, many definitions that have evolved over years, and maybe within particular disciplines?

I think the everyday use of "metaphysical" is something like this:
Metaphysical
(popularly) abstract, abstruse, or unduly theoretical.
Incorporeal; supernatural.
— Collins English dictionary

But I think we need something better than "stuff that's a bit weird" for our use, don't we? :wink:

Accepting that "metaphysics" is used to describe quite a lot of philosophical thinking, the 'definition' that means most to me is one I thought I read in Pirsig's first novel. I've looked for it recently, and can't find it. Maybe I invented it? Anyway, I got the impression that if we start from all thought, ideas, and so forth, and we start to divide it, in order to reduce the pieces to bite-size. We might divide Everything into (say) Subject and Object. Then we would proceed to make further cuts. This process of deciding how to subdivide Everything is metaphysics.

But I'm sure you've got better ideas than this. What are they? What definition(s) of metaphysics do you find the most useful and meaningful? — Pattern-chaser

I like the answer that says its just an attempt to clarify what is. 30 years of reading books on physics, especially QM, but GR etc as well, and philosophical writings on it by people like Wittgenstein (conventionalism), Poincare (conventionalism as well), Turing (applications were paramount. But had a magnificent debate with Wittgenstein about one of the most fundamental of things - math - https://www.britishwittgensteinsociety.org/wp-content/uploads/documents/lectures/Turing-and-Wittgenstein-on-Logic-and-Mathematics.pdf . Its ironic that before being a philosopher Wittgenstein used applied math all the time as an aeronautical researcher), Weinberg (realist - science is progressing towards something), Kuhn - well I am sure you get my drift - I still have no firm idea. I think its one of those things you need to read and form your own view - if you can - like I said I can't. I recently found a little known discussion between Dirac and Heisenberg that helped me quite a lot:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.485.9188&rep=rep1&type=pdf

I side with Dirac in that what is, is never really known, we just continually advance theories about it. Weinberg thinks we are advancing towards something, I think he is right, but bowed if I can justify it.

To me it's maddening we cant even pin it down well. — Bill Hobba