If mental constructs exist then I guess a fortiori consciousness must also exist.

If mental constructs exist then I guess a fortiori consciousness must also exist. — Pantagruel

Per the rule above, as idea. But I wonder if you'd care to make the argument that consciousness is some kind of material thing, for it must seem that while ideas may exist, and come and go, that that which has them cannot be as ephemeral, or as ephemeral in the same way. Nice point, either way!

Yes, I thought that consciousness "having" an idea ought to be different from conscious qua idea. Unless we are saying that an idea can have an idea?

Yes, I thought that consciousness "having" an idea ought to be different from conscious qua idea. Unless we are saying that an idea can have an idea? — Pantagruel

I think you're on to something. Now make the case! I'm in between, because I suppose that existing things inhere in something somehow. Per above, material or idea. Are we thus obliged to subsume idea and consciousness under the material existence of the brain? And it must seem, then, that every question of being then is at the same time a question of materiality - which it may be! On the other hand, consciousness a fortiori calls for a something that is conscious....

If you might stub your toe on it, then it's difficult to see how it isn't. — tim wood

Argumentum ad lapidem (English: "appeal to the stone") is a logical fallacy that consists in dismissing a statement as absurd, invalid, or incorrect, without giving proof of its absurdity.

Ad lapidem statements are fallacious because they fail to address the merits of the claim in dispute. The same applies to proof by assertion, where an unproved or disproved claim is asserted as true on no ground other than that of its truth having been asserted.

The name of this fallacy is derived from a famous incident in which Dr. Samuel Johnson claimed to disprove Bishop Berkeley's immaterialist philosophy (that there are no material objects, only minds and ideas in those minds) by kicking a large stone and asserting, "I refute it thus." This action, which is said to fail to prove the existence of the stone outside the ideas formed by perception, is said to fail to contradict Berkeley's argument, and has been seen as merely dismissing it. — Wikipedia

To add to which, the basic nature of ‘material things’, if that is presumed to be atomic matter, is itself unresolved at this point in history. The apparent solidity of the atom has dissolved into uncertainty and probability; Russell even observes this in his concluding chapter of HWP. Meanwhile the irreducible nature of mind has been restored to philosophy, in movements such as semiotics, quantum baysianism, and many other forms.

So I’m afraid your ‘argument ad lapidiem’ is not going to succeed.

I don't think we have to assume reductionism. Chemical properties emerge from physical systems which have evolved to a certain level of complexity, but chemical properties are not reducible to physical properties. They are undeniably real, and form the basis of further empirical inquiry. So why should consciousness be any different than that?

So I’m afraid your ‘argument ad lapidiem’ is not going to succeed. — Wayfarer

I wonder if you misread. I merely say that if you stub your toe on it, then it's hard to argue that the thing that you stubbed your toe on does not exist.

I don't think we have to assume reductionism. Chemical properties emerge from physical systems which have evolved to a certain level of complexity, but chemical properties are not reducible to physical properties. They are undeniably real, and form the basis of further empirical inquiry. So why should consciousness be any different than that? — Pantagruel

Consciousness then as manifest in a process? That makes some sense. there are things that require minima or maxima of constraint to exist, below (or above) which, they don't.

I wonder if you misread. — tim wood

It is exactly the point of what I wrote. Do you understand why Samuel Johnson said that of George Berkeley's philosophy, and why his response is regarded as fallacious?

Well, to start with, there's the tile in the southwest corner of my bathroom, and then the tile just to the east of that, and then the tile just to the east of that, and so on, until about 50 tiles later we get to the southeast corner of the bathroom. And then we move a row north and do it all again, and so on.

Or is that not the sort of thing you have in mind?

I'll leave it to someone else to list each grain of sand.

I offer here what I think is an exhaustive listing (i.e., why it might be a short thread).

1) All material things.
2) All other things existing by reference, but not material, as ideas/mental constructs. — tim wood

Just for fun, trying to think of some"thing" that falls outside these two categories...

What about the relationships between "things"? They can be physical or abstract, but either way, seem to be a different type of "thing"? Or maybe not...I am not entirely convincing myself either way, haha.

This should be a short thread that generates little controversy. The idea is to list as many differing kinds of existing/existence/existing things as we can think of. Part of the goal is to identify which things/classes of things may be reasonably said to exist, and also both to weed out unsupportable claims and to rule out "things" for which there is no direct evidence.

Now for some guidelines, all of which are tentative and offered to facilitate reasonable colloquy, and that are amendable for cause.

1) We need a word of convenience to refer to the what it is we shall be listing. The word "thing" irresistibly suggests itself. Being mindful that our usage will inevitably include reference to things not usually either called things or regarded as things - understanding the ambiguity - we adopt "thing" as being merely a pointer word, itself agnostic as to the thing referred to.

1a) Material existence shall be an absolute qualification for existence - the materiality, obviously, being demonstrable. If you might stub your toe on it, then it's difficult to see how it isn't.

2) It must seem as if a lot of things will be almost automatically included into the list of things that exist. The earth, a pencil, brick, chair, airplane, & etc. There's no need to list multiple individuals if they may all be entered as a class. And in this there may quickly emerge a taxonomy of sorts, of existing things. Classes of things, then, supersede individuals, they being included mutatis mutandis in the class.

3) It's possible that some contention may arise as to whether a candidate thing exists, which may include reference to the how of the existence claimed. For example, two, the number, may be claimed to exist, the question of how or in what form then arising. Platonists may claim that two has some super-sensible existence as a Platonic form. For present purpose all such, for inclusion in a listing of existing things, must be listed as ideas/mental constructs - the existence of two as an idea being self-evident, and any claim beyond that being no more than a claim. The test here being demonstrability, and the further from being self-evident the candidate being, the more rigorous the demonstration ought to be. Or in short, the thing either exists self-evidently (which may be subject to challenge), or some demonstration proves its existence, the proof based in self-evident propositions. No Voodoo, no woowoo.

I offer here what I think is an exhaustive listing (i.e., why it might be a short thread).

1) All material things.
2) All other things existing by reference, but not material, as ideas/mental constructs. — tim wood

thats fair. Pencils do in fact exist.

Do you understand why Samuel Johnson said that of George Berkeley's philosophy, and why his response is regarded as fallacious? — Wayfarer

Because Johnson did not understand that Berkeley was referring to the so-called "philosopher's substance" and thought instead that he was referring to the stone itself.

I'll leave it to someone else to list each grain of sand. — Terrapin Station

There's no need to list multiple individuals if they may all be entered as a class. And in this there may quickly emerge a taxonomy of sorts, of existing things. Classes of things, then, supersede individuals, they being included mutatis mutandis in the class. — tim wood

???

What about the relationships between "things"? They can be physical or abstract, — ZhouBoTong

A physical relationship? Care to say how that is?

Do you understand why Samuel Johnson said that of George Berkeley's philosophy, and why his response is regarded as fallacious?

— Wayfarer
Because Johnson did not understand that Berkeley was referring to the so-called "philosopher's substance" and thought instead that he was referring to the stone itself. — tim wood

No, I don't think that's it.

Your OP starts with:

Material existence shall be an absolute qualification for existence - the materiality, obviously, being demonstrable. If you might stub your toe on it, then it's difficult to see how it isn't. — tim wood

which is basically the claim that 'the existence of material objects is indubitable'. But it was just this claim which Berkeley calls into dispute. He does this by claiming that what we think to be stones and other external objects are really ideas and sensations in our own minds. He precisely denies that there are material substances at all.

Samuel Johnson claims to have refuted this by simply kicking against a large rock, exclaiming 'I refute it thus!' But his 'refutation' is said to be fallacious, insofar as it simply assumes that Berkeley's claim is wrong or nonsensical, without offering any real rebuttal of it. (Hence the designation of it as 'argumentum ad lapidiem', the argument from the stone.)

In a more general sense, you're simply assuming a position of common-sense realism, as if that is the sine qua non of philosophy, proper; and then venturing that anything we might care to claim exists, must meet the criterion of being either a material existent, or an idea in the mind.

What you don't see, is the sense in which this realist paradigm is itself a kind of construction, in the sense understood by critical philosophy (e.g. Schopenhauer's 'vorstellung', meaning 'representation' or 'idea'.) Critical philosophy does dare to call into question the existence of what we would normally assume to be real - that is its understanding of what philosophy does. Whereas, you're starting from a pre-critical, or non-critical, stance of naive realism, and challenging others to show what's wrong with it (which I am endeavouring to do).

For example, two, the number, may be claimed to exist, the question of how or in what form then arising. Platonists may claim that two has some super-sensible existence as a Platonic form. For present purpose all such, for inclusion in a listing of existing things, must be listed as ideas/mental constructs - the existence of two as an idea being self-evident, and any claim beyond that being no more than a claim. — tim wood

I think the point here, is that natural numbers are the same for all who can count. So in that sense, they're not 'ideas' in the sense of being 'internal to the mind'; they're not dependent on my mind or yours. But at the same time, they are 'intelligible objects', in other words, any system of numbers or symbols we use, must have a constant referent, otherwise our maths will be wrong. And maths is predictive of reality, so it extends beyond what is simply in my mind or yours, but at the same time, the kind of reality it has is purely intelligible, i.e. can only be grasped by a rational mind.

So what you're really trying to wrestle with in this OP, is the whole question of ontology - of what is the nature of existing things. But you're starting from the unquestioning assumption that what we can sense to be real, is the sine qua non of what exists; whereas, once we begin to acknowledge the reality of such mental objects as numbers and logical laws, then it becomes clear that what we can encounter as an external object might only be one aspect of reality as such, and may not even comprise its fundamental constituents.

So you could just make the top-level class "stuff" and leave it at that.

Or in other words, classes/kinds/types are simply a matter of how we want to conceptualize things, how we want to divide them up.

This the first thing from the internet:
"George Berkeley's philosophy. George Berkeley is an Irish philosopher (1685-1753) of English descent, best known for the doctrine that there is no material substance and that things, such as stones and tables, are collections of “ideas” or sensations, which can exist only in minds and for so long as they are perceived."

The key phrase is "no material substance." The ideas of stones & etc., are indeed ideas, but the underlying reality of them was not the target of Berkeley's attack. I recommend some research on this for concision and clarity. Had Johnson understood, which he did but in an upside-down way, instead of kicking anything, Boswell would have quoted him as saying, "Damn right!"

As to the claim of the indubitability of the existence of material objects like stones, are you going to argue that they do not exist, period? Even at the start, one might ask what it was, exactly, that you were arguing did not exist - and then we're off on a tour of rabbit holes. So you may as well announce yourself here: does anything exist, or does everything not exist? Of existing things, if there are any, are all, some, or none, material objects?

In any case, no one argues that the stone simply does not exist, certainly not Berkeley.

He precisely denies that there are material substances at all. — Wayfarer

In this you get exactly the point, you just don't yet know it.

In a more general sense, you're simply assuming a position of common-sense realism, as if that is the sine qua non of philosophy, proper; and then venturing that anything we might care to claim exists, must meet the criterion of being either a material existent, or an idea in the mind. — Wayfarer

I do not see philosophy as being altogether detached from reality. That would be just a game. At the moment I'm not interested in playing a game - maybe someone else.... As to the two criteria suggested above, do you have categories of existence to add? My own view is that categories cannot simply be asserted without some convincing argument, else we be without any criteria and the concept of existence thereby meaningless.

Are numbers a category? You can't show me one, nor demonstrate the existence of any absent mind - or so I think. Have at it. (And why limit yourself to natural numbers? Why not all numbers?)

...once we begin to acknowledge the reality of such mental objects as numbers and logical laws.... — Wayfarer

But you have to have the underlying ideas before you can even approach these. Yes, the laws are real - as ideas. If you wish to demonstrate that they are not ideas, then you cannot have ideas to demonstrate them. Try kicking one? How do you have two without mind?

Maybe I should offer a tentative definition of existence, or at least that which falls out of my two categories above: objects of thinking or sense or some combination, but in combination reducible to either object of thought or sense by parts.

So you could just make the top-level class "stuff" and leave it at that.

Or in other words, classes/kinds/types are simply a matter of how we want to conceptualize things, how we want to divide them up. — Terrapin Station

Maybe, as the collection of everything that exists includes everything that exists, but does that help? As to classes and types, do you really have a problem having a class of sand that includes as members all the individual grains of sand? Of course, if you insist that it is all just how we want to conceptualize, that puts it "all" into the category of ideas.

A physical relationship? Care to say how that is? — tim wood

Block A is next to block B.

Rope C connects blocks A & B.

Force X effects object Y

Even if it takes language to express the relationship, it does physically exist (right?)...Am I making any sense?

The key phrase is "no material substance." The ideas of stones & etc., are indeed ideas, but the underlying reality of them was not the target of Berkeley's attack — tim wood

Of course it was. I have a BA including two years of undergraduate philosophy, I understand it perfectly clearly, thank you. It is the independent existence of the objects of perception which is precisely what is called into question by Berkeley. What you say is 'the underlying reality' is simply your realist assumption speaking - you haven't gotten to the point of what exactly is at issue, which is precisely the sense in which they have, or do not have, any underlying reality. And Berkeley claims they don't. If you don't find that shocking, or if you think that Berkeley is just playing with words, then you're not getting it.

Maybe I should offer a tentative definition of existence, or at least that which falls out of my two categories above: objects of thinking or sense or some combination, but in combination reducible to either object of thought or sense by parts. — tim wood

Clearly that is what you think, but it is not informed by philosophical analysis.

Don't we need a definition of what it means to "exist" before we can proceed with an inquiry like this? The difficult thing is to get a definition which we can all agree on. If you define "exist" as "being material" then you'll be accused of being a materialist begging the question. So I propose something like "being present' as defining what it means to exist.

There are two distinct ways of being present. One is to be at a certain place, and the other is to be at a certain time. Therefore I suggest that there are two different ways of existing.

Some of the typical categories that seems to come up regularly ...

real and fictional
maybe existentially mind-independent and mind-dependent (qualia?)
spatial (left to right, top to bottom, front to back) and process (starts and ends, comes and goes)
interactees and interaction (and transformation)
self (indexicals) and other
particulars (examples) and generals (abstractions)
maps and territories (models and evidence)

... or some such like.

The difficulty I have is that the relationship is no thing separate from the objects themselves. Two stones are near each other, and no others are close. That must be two, yes? No. the two is in the mind of the observer who associates the idea of two with the two stones. No mind, no two, is my argument. And similarly with anything that is called a relationship.

But you also mentioned force. And I'm thinking about that. Force does not seem an object. The apprehension of the manifestation of the presence of a force could be called an idea, but I think that misses the point.

I'm looking on line for a definition of force , but haven't found a good one. How would you define "force?"

Berkeley presents here the following argument (see Winkler 1989, 138):
(1) We perceive ordinary objects (houses, mountains, etc.).
(2) We perceive only ideas.
Therefore,
(3) Ordinary objects are ideas.
The argument is valid, and premise (1) looks hard to deny. What about premise (2)? Berkeley believes that this premise is accepted by all the modern philosophers. In the Principles, Berkeley is operating within the idea-theoretic tradition of the seventeenth and eighteenth centuries. In particular, Berkeley believes that some version of this premise is accepted by his main targets, the influential philosophers Descartes and Locke. (https://plato.stanford.edu/entries/berkeley/#2.1.1)

Thus, for example, a certain colour, taste, smell, figure and consistence having been observed to go together, are accounted one distinct thing, signified by the name apple. Other collections of ideas constitute a stone, a tree, a book, and the like sensible things; which, as they are pleasing or disagreeable, excite the passions of love, hatred, joy, grief, and so forth.
As this passage illustrates, Berkeley does not deny the existence of ordinary objects such as stones, trees, books, and apples. On the contrary, as was indicated above, he holds that only an immaterialist account of such objects can avoid skepticism about their existence and nature. What such objects turn out to be, on his account, are bundles or collections of ideas. An apple is a combination of visual ideas (including the sensible qualities of color and visual shape), tangible ideas, ideas of taste, smell, etc.[12] The question of what does the combining is a philosophically interesting one which Berkeley does not address in detail. He does make clear that there are two sides to the process of bundling ideas into objects: (1) co-occurrence, an objective fact about what sorts of ideas tend to accompany each other in our experience, and (2) something we do when we decide to single out a set of co-occurring ideas and refer to it with a certain name (NTV 109).

Thus, although there is no material world for Berkeley, there is a physical world, a world of ordinary objects. This world is mind-dependent, for it is composed of ideas, whose existence consists in being perceived. For ideas, and so for the physical world, esse est percipi.(https://plato.stanford.edu/entries/berkeley/#3.1.1)
-----------------------

"There is a physical world, a world of ordinary objects." if Berkeley affirms the physical world of ordinary objects, then what, exactly is it he denies. My answer, 1) that the ideas that correspond to the ordinary objects are themselves material substance, and 2) that there is no philosopher's underlying material substance as described by Locke.

--------------------
Locke on ‘pure substance in general’
Locke expresses this idea as follows:

The idea then we have, to which we give the general name substance, being nothing, but the supposed, but unknown support of those qualities, we find existing, which we imagine cannot subsist, sine re substante, without something to support them, we call that support substantia, which, according to the true import of the word, is in plain English, standing under or upholding. (II xxiii 2)

The traditional rationale of Locke’s doctrine of ‘substance in general’ is as follows. Properties—or, in Locke’s terms qualities—must belong to something—‘cannot subsist…without something to support them’. Of course, they belong to objects, but what are objects over and above their properties? The special category of substantial form, as found in Aristotle, is rejected. All that seems to be left is a bare ‘something’, which on pain of regress, has no properties in its own right, except the property of being the owner or support of other properties.(https://plato.stanford.edu/entries/substance/#MedAccSub)
---------------------------

Clearly that is what you think, but it is not informed by philosophical analysis. — Wayfarer

Am I to suppose that you are arguing that the stone does not exist? Nor do I claim to have made an analysis, but just to have thought about existence and what can be said to exist, and how. Have I erred somewhere? Do stones demonstrably not exist? That would be tricky ground. Do ideas not exist? And are there other categories I've overlooked? @ZhouBoTong mentions above forces. I'm thinking forces are non-material existing things, but I'm not sure, nor have I figured out the consequences.

Don't we need a definition of what it means to "exist" before we can proceed with an inquiry like this? The difficult thing is to get a definition which we can all agree on. If you define "exist" as "being material" then you'll be accused of being a materialist begging the question. So I propose something like "being present' as defining what it means to exist. — Metaphysician Undercover

I offered this above as tentative:

Maybe I should offer a tentative definition of existence, or at least that which falls out of my two categories above: objects of thinking or sense or some combination, but in combination reducible to either object of thought or sense by parts. — tim wood

"Being present." Hmm. The test I'm using is negation. For my two, that is, if not an object of thought or a material object, then not existing. For "being present" it would be, if not present then not existing. Hmm again. Will you accept an amendment to, "Having the capacity to be present in some sense or some way"? Meaning that lacking any such capacity means non-existence. Is that what you meant? Sorry to make it longer.... But that will just establish existence or non-existence. Maybe the manner of the existence will also place it in a taxonomy of existing things.

For my purposes and understanding, the test for existence and type ought to be a comprehensive test that will among other things preserve the integrity of the concept of existence, such as it has. Else everything exists in whatever way anyone claims, and that's not much good.

As this passage illustrates, Berkeley does not deny the existence of ordinary objects such as stones, trees, books, and apples. On the contrary, as was indicated above, he holds that only an immaterialist account of such objects can avoid skepticism about their existence and nature. — tim wood

So do you accept his ‘immaterialist’ account? Because it certainly seems hard to reconcile with your 1(a).

So do you accept his ‘immaterialist’ account? Because it certainly seems hard to reconcile with your 1(a). — Wayfarer

I recognize that world-class philosophers operate within their schools of thought, about which my own knowledge is equivocal. So I try not to got there. If we have an argument, it would be over what you say v. what I say, not what someone else wrote a long time ago, filtered through claims about that subject matter. Those thinkers can certainly instruct, but the lesson needs be taken with a modicum of care The question to you is, Does the stone exist?

How about 'stupidity'? It seems very real to me.