This is about "Things in themselves" a concept which is easy to misunderstand. Let me see if I can do it justice.

A "Thing in itself" is 'reality'. It is "What is". What we do as people is observe light, air vibrations, etc, then piece together a coherent assessment of "That thing in itself" that we can process and make sense of. But if you think about it, the "Thing in itself" is not the light bouncing off. The falling tree does not make sound, the air from the crash does. As such, it is impossible to know what "A thing in itself" is. Its that upon which we represent with our definitions, beliefs, assumptions, and knowledge.

Generally, the debate is, "Can we know what a thing in itself is?" Can we know what reality is, apart from our interpretations of that reality? And the answer is "No". What we call "space" has no directionality, as directionality is related to our interpretation. It doesn't mean that space doesn't exist or that something like "up" doesn't exist 'in itself'. It just means that our interpretation of what is, that exists without contradiction, still isn't "what is".

And this makes sense right? If you can only interpret something, you can't know what the something is without interpretation. In a more relatable sense, you can't actually 'be' another consciousness than yourself. You can interpret another human being, make beliefs about them, assessments, etc., but you can never understand what it is like to be "That person in themselves". And to really make sure this is understood, it does not mean that "That person in themselves" does not exist. It just means you're ability to understand and know about it is limited by the aspects of information and interpretation.

So ok, lets see if we can make the above conversation make more sense then a late night edible conversation.

this basic argument in the 1768 essay is that Leibniz’s view does not enable one to distinguish between a left handed glove and a right handed glove, insofar as the relations of all the parts to one another are the same in both cases. — SEP on Leibniz

Ok, so the glove can fit a right hand or left hand. That's the thing in itself (which we shouldn't be able to know). We ascribe to that glove, "Its a right handed/left handed glove", but because there is nothing innate in the glove itself that would necessitate that its right or left handed, we can make a belief, but not a solid claim of "that's what it is in itself".

Yet if God had created just one glove, it would have been one or the other. — SEP on Leibniz

What he's doing here is noting that the glove was made with intention. So the design does not convey the intent of the glove, but the designer had an intent for the glove. This is pulling the idea that 'things in themselves' are of course intelligently designed. And if you understand the what I noted above, you get into some absurd logic. Essentially even though we interpret reality, God actually understands and knows reality as it is 'itself'. How? Magic. And continuing to create a reasonable argument with magic ends in nonsense.

Another way to look at it is that God is another stand in for 'conscious intelligent being'. And its Gods interpretation that the glove be used for right hands only, so therefore its a right handed glove. But God would still need the concept of right and left handed that does not exist in 'the thing in itself'. Generally when you pull God into a conversation, it gets weird. I'll try to leave that aspect out to make it more intelligible.

Right-handedness and left-handedness are not merely anthropic concepts since nature itself insists on handedness in twining plants and the shells of snails. But which direction is right and which is left can only be established by a conscious, embodied being. As he expresses it in the Prolegomena, “The difference between similar and equal things which are not congruent…cannot be made intelligible by any concept, but only by the relation to the right and left hands, which immediately refers to intuition” — SEP on Leibniz

In other words if there were no hands, we would not be able to ascribe that a glove was for a right or left hand. But since there are hands created by nature, we know there are right and left hands in themselves. Nature doesn't ascribe to it that, "This is the right hand", but it there are hands that exist on each side of the body. Our interpretation or 'intuition' is to know them as right and left hands. Nature doesn't know them as that, as nature does not ascribe to them anything more than they are. The mistake here is to think that there is another concept 'in itself', or as God would ascribe. A thing in itself has no concept, it just 'is'.

It is not clear whether this orientational analysis implies that wherever there is space there must also be sentient beings with pairs of incongruent parts, as well as top-bottom and back-front asymmetry. — SEP on Leibniz

So again, to know something is 'right or left' is a human concept based on relation. "Right" is what we call 'that horizontal direction' in relation to left which is 'the complete opposite direction' from a particular origin viewpoint. "Right" and "left" do not exist, according to the above, as 'things in themselves'. They are pure concepts based off of relations of our interpretations of things in themselves.

So that being the case, if right and left are conceptual relations, doesn't that mean that top, back, depth, height, and space in general is just a concept based on the relations that a cognizant being creates? Yes. But does that mean the things in themselves are not related to other things in themselves, as they are? No. Does putting God or Forms into the mix make it more confusing then it needs to be? Yes. :)

Ok, so now to finally answer your question!

On what basis do you make this distinction? Is it a matter of experiencing the world through a human body? Or is there something objective about it? — frank

The objective basis is 'the thing itself'. We have 'hands' in themselves. How we interpret them is up to us. We could call them "quack and bark" hands if we wanted. We could say that hands involve the forearm. We part and parcel our interpretation of reality as we wish. As long as our interpretation is not contradicted by the thing in itself's existence (I can cut my hands off and they will still work does NOT match reality) then we're good.

Ok, so now to finally answer your question!

On what basis do you make this distinction? Is it a matter of experiencing the world through a human body? Or is there something objective about it?
— frank

The objective basis is 'the thing itself'. We have 'hands' in themselves. How we interpret them is up to us. We could call them "quack and bark" hands if we wanted. We could say that hands involve the forearm. We part and parcel our interpretation of reality as we wish. As long as our interpretation is not contradicted by the thing in itself's existence (I can cut my hands off and they will still work does NOT match reality) then we're good. — Philosophim

Yes, the question is whether or not space has mind-independent directions. That question doesn't appear to be answered by noting that we have hands. I think you're agreeing that space does not have any innate directionality (in the same way there is no unmoving reference point out there). Adding more objects doesn't fix that. So there is no "up" in itself.

Adding more objects doesn't fix that. So there is no "up" in itself. — frank

There is a distance between a set point in itself, and another set point in itself. "Up" is an interpreted relation between our observation view point, and that relation. So yes, "Up" does not exist in itself, but the Earth, and the distance to space for example, does exist in itself.

There is a distance between a set point in itself, and another set point in itself. "Up" is an interpreted relation between our observation view point, and that relation. So yes, "Up" does not exist in itself, but the Earth, and the distance to space for example, does exist in itself. — Philosophim

Right. "Up" is observer dependent. That one's a little harder for me to grasp than left-right. :grin:

I distinctly remember struggling with this for at least weeks, maybe longer, as a 4-5 year old. Knowing there was a difference, looking at my hands, thinking they looked the same. How do I know which one's my left one? I can't tell. They look the same.

Those were weird times man, what a trip.

Left-right confusion is surprisingly common. I have known three otherwise smart adults who can't tell the difference and need constant prompting. According to Wiki 15% of people have LRC.

On what basis do you make this distinction? Is it a matter of experiencing the world through a human body? Or is there something objective about it? — frank

I think of myself as having two halves and I know the left is the side I don't write with. I think that's how I tell the difference. Is it objective? It's certainly an intersubjective agreement shared by culture - a tool we use to organise space. While there might be some who are confused as to which is which. Those who can tell will always agree as to which is which. Does that make it objective? Of course, further complicating this is that left or right change depending upon one's position or perspective - they are not like compass points.

I think of myself as having two halves and I know the left is the side I don't write with. I think that's how I tell the difference. Is it objective? It's certainly an intersubjective agreement shared by culture - a tool we use to organise space. While there might be some who are confused as to which is which. Those who can tell will always agree as to which is which. Does that make it objective? Of course, further complicating this is that left or right change depending upon one's position or perspective - they are not like compass points. — Tom Storm

I guess the point is that it's not mind-independent. We need a conscious entity (or two) in order for directionality to exist. All by itself, space doesn't have directions like left and right. That's kind of mind-blowing if you're used to thinking in terms of absolute space.

All by itself, space doesn't have directions like left and right. — frank

That seems intuitively true.

That seems intuitively true. — Tom Storm

So it would go back to the hand you write with, unless you're left handed? :grin:

I am left-handed. Many of those strengths appeared by what the right hand did better. I write on paper left-handed but many other tasks, like playing piano or cutting with scissors are better done with the other side. It seems to me there is a dynamic where the two sides are using the oppositional quality for a kinesthetic affect.

But which direction is right and which is left can only be established by a conscious, embodied being. — SEP on Leibniz

Sure. But this is true of everything - everything expressible as a concept.

Yes, the question is whether or not space has mind-independent directions. That question doesn't appear to be answered by noting that we have hands. I think you're agreeing that space does not have any innate directionality (in the same way there is no unmoving reference point out there). Adding more objects doesn't fix that. — frank

I'm not sure how this fits into this discussion, but there is a physical property - chirality - the technical term for handedness.

I call any geometrical figure, or group of points, 'chiral', and say that it has chirality if its image in a plane mirror, ideally realized, cannot be brought to coincide with itself. — Lord Kelvin

Certain chemicals - primarily organic compounds - form chiral pairs. Generally, but not always, they behave the same chemically. Chirality is also a property of some subatomic particles, e.g. the spin of an electron.

That doesn't change the fact that deciding which direction you call right and which left is a matter of convention, but it's a convention that makes some sense. 90% of people are right-handed. Left-handed people were sometimes considered sinister, which means "left."

You can however tell that one glove is the chiral opposite of the other. If the gloves have palm and back, then you can certainly tell which is left and which is right. And if they don't, then it doesn't make any difference, since you can turn left into right by the simple expedient of turning the glove inside out.

The supposition is that somehow therefore consciousness is essential to telling left from right, but the case for this cannot, I think, be made. All that is needed is an arbitrary point from which to assess the chirality of the glove.

Ok, so the glove can fit a right hand or left hand — Philosophim

I'm not sure I follow. As Banno says:

If the gloves have palm and back, then you can certainly tell which is left and which is right. — Banno

Gloves look very different depending on which hand they are supposed to fit.

If the question is whether 'left' and 'right' exist independently of any specific spatial observation point, I can't imagine how they could. What would anything be 'left' or 'right' of? They are relational terms. But I sense I'm misunderstanding a deeper philosophical question.

As it happens, I am one of those unfortunate souls who often gets confused between left and right. But, of course, I never confuse 'up' with 'down' or 'backwards' with 'forwards'. (Not that I'm suggesting those directions are any more independent of an observer! Just an observation).

Ok, so the glove can fit a right hand or left hand
— Philosophim

I'm not sure I follow. As Banno says:

If the gloves have palm and back, then you can certainly tell which is left and which is right. — cherryorchard

Because the authors were not talking about gloves with palms and backs. They were specifically providing examples of gloves that had no distinct indicators that they were for left or right hands. Think of disposable plastic gloves that medical providers use if that helps.

If the question is whether 'left' and 'right' exist independently of any specific spatial observation point, I can't imagine how they could. — cherryorchard

This is the important part. But does that mean a right and left hand don't exist? No. The issue is in trying to describe 'things in themselves'. You really can't. Any descriptor or knowledge of a thing in itself is going to be a representation. So we can know there is reality, just not know what it is if we could not interpret and represent it in some way that relates to us.

Because the authors were not talking about gloves with palms and backs. They were specifically providing examples of gloves that had no distinct indicators that they were for left or right hands. Think of disposable plastic gloves that medical providers use if that helps. — Philosophim

That makes perfect sense – sorry for misunderstanding. But in the case of those sorts of gloves, there are no ‘left’ or ‘right’ gloves, any more than there are ‘left’ or ‘right’ socks. I don’t see why we need to imagine the glove floating in an empty container. Nor would the addition of a human spectator answer the question of whether it is a left or right glove – it is neither.

The supposition is that somehow therefore consciousness is essential to telling left from right, but the case for this cannot, I think, be made. All that is needed is an arbitrary point from which to assess the chirality of the glove. — Banno

Being in a quadruped body is the basis for the distinction. Directionality is something we give to space. It doesn't have that on its own. Some responders to this thread have said that this is blatantly obvious, others like me, arrived at it intellectually, but it still seems weird, then there are people who reject it?

I don’t see why we need to imagine the glove floating in an empty container. Nor would the addition of a human spectator answer the question of whether it is a left or right glove – it is neither. — cherryorchard

Its a thought experiment used to convey an underlying idea. You're making an innocent mistake of focusing too much on the specifics of the thought experiment, and not what its trying to get at. The specifics of the thought experiment are irrelevant as long as you understand the main idea its trying to convey.

The point is that sometimes the existence of a thing does not innately imply things we ascribe to it. We ascribe direction based on points of origin, or use. But only a conscious being can construct a point of origin or use. Do left and right describe things in themselves, or are they purely constructs of an intelligent observer?

But only a conscious being can construct a point of origin or use. — Philosophim

:up: It's a kind of relativity.

This is interesting from stack exchange.

Being in a quadruped body is the basis for the distinction. — frank

Quadruped? That's my problem then. Not enough feet.

Directionality is something we give to space. It doesn't have that on its own. Some responders to this thread have said that this is blatantly obvious, others like me, arrived at it intellectually... — frank

You reached it as a conclusion to some argument? This?

Consider a container in which a single glove is floating. Is it a right-handed glove or a left-handed glove? We can insert various new items into this space-container, e.g., an anorak, a scarf, a shoe, but only the insertion of a human observer into the space will permit an answer. — SEP on Leibniz

It's wrong. If the glove has a palm and a back then we can tell its chirality. If it does not have a palm and back then inserting an "observer" does not help. The judgement will depend on which side the glove is seen from, not on the fact of there being an observer. It's not necessary to "insert an observer" to settle the issue; simply choosing a point on this or that side of the glove will suffice.

"Directionality" results from there being more than one point in a space. The minimum number of points sets the dimensionality - two points, one dimension, three points, two dimensions, four points, three dimensions. No observer is needed.

But only a conscious being can construct a point of origin or use. — Philosophim

This looks to be a play on "use". Only conscious beings construct. But that tells us nothing about space.

If the conclusion here is supposed to be that space cannot exist without conscious beings, and hence that some form of antirealism must be true, then it is very unconvincing. There's a notion hereabouts that our explanations are incomplete until consciousness is introduced, and an ensuing drive to bring consciousness in to all sorts of discussions, to somehow prove that consciousness is something special. As if the fact of one's own consciousness were not extraordinary enough! As if you somehow need to demonstrate your existence, as well as to live it! But of course you cannot doubt your own consciousness, so all such supposed demonstrations are besides the point. It's an example of a misplaced need for certainty, as if that the glove is left-handed were more evident than that you are conscious. I find such approaches extraordinarily muddled.

It's not necessary to "insert an observer" to settle the issue; simply choosing a point on this or that side of the glove will suffice. — Banno

How can you have choosing going on with nobody to choose?

Quadruped? That's my problem then. Not enough feet. — Banno

Tetrapod.

How can you have choosing going on with nobody to choose? — frank

Your observer is reduced to a point. That is all that is needed.

How could this discussion go on without you and I? If your purpose is to prove that there are observers, then it seems to me that your argument is superfluous. That there is a discussion is sufficient.

Your observer is reduced to a point. That is all that is needed. — Banno

So you have an observer.

No. We have a point.

We have a point. — Banno

Which point?

Any point.

Any point. — Banno

So you have a point. Now what?

Now you have chirality.

Now you have chirality. — Banno

I don't see what you're talking about. Where's the point?

Anywhere off the plane.

https://en.wikipedia.org/wiki/Chirality_(mathematics)