Sensible things can be divided. Or at least, they can if they are physical things - that is, if they take up space. For anything that takes up some space can be divided in two. One can have half a mug, half a piece of cheese, half a molecule, and so on. But not half a mind. Well, if all things that are extended in space can, by their very nature, be divided and one's mind cannot be divided, then one's mind is not extended in space and is thus not a sensible object. (This venerable argument, versions of which can be found in Plato, Descartes and Berkeley among others, seems by itself sufficient to establish that the mind is immaterial, not material). — Bartricks

Significantly, both mug and mind are concepts. They are not actual things that exists independently and each have various aspects. Depending on how you cut a mug in half it may more retain or lose its ‘mugness’. If you cut it vertically it will no longer be able to function as a mug. It you cut it horizontally it can still function as a mug, though a shorter one with less capacity. In a very real sense the vertically cut mug is no longer a mug.

Moving on to minds, it just so happens that there are brains that have been medically split.
According to Lizzie Schechter, assistant professor of philosophy and philosophy-neuroscience-psychology at Washington University in St. Louis, “The impression that a split-brain subject has two minds is correct”. I won’t bother posting the evidence for her conclusion. If split-brain research interests you it’s easy to look up. Cutting the corpus callosum doesn’t produce two identities, however, so if your concept of a mind requires a human self-identity this example may be inadequate. Of course that would mean that you don’t regard most species as having minds because they don’t possess human minds with our sense of self.

ll your life you've depended on your senses, never doubted them — TheMadFool

Of course. What else could I do? These were and are my senses. What's the use or purpose doubting them? What could I gain from such a thing? In fact, if I did such a thing, on a constant basis, I wouldn't be able to write these lines, or any lines, for that matter. I would be living in an asylum! :smile:

normal mental state
— Alkis Piskas
How do we know that we are normal? — TheMadFool

What's there not to undestand?
Normal = "Conforming to a standard; usual, typical, or expected" (Oxford LEXICO)
And I talked about our normal state, not normal state in general. Our personality, the basic characteristics of our behaviour and all that depend on and are dictated by our mental state. Which, i a sane person, is stable in general and under normal conditions. Not only ourselves but also others can recognize it. (I warn you: Don't ask me what do I mean by "normal conditions" because I won't answer it! :grin:)

TheMadFool makes a good point and they can all happen to an entirely healthy person — Mark Nyquist

Certainly they can. But then, these indicate an abnormal condition, as I said. And certainly, one cannot trust his senses in such a condition. (I have already explained all that. Most probably you have not read my whole post ...)

I think this is on topic and a little study on how thoughts can go wrong.
Philosophy might have something to add as far as insights into troubleshooting psychosis. Maybe just a little off topic.

So, just to be clear, you're claiming that doing things to the brain does not affect the mind?

Significantly, both mug and mind are concepts. — praxis

No they're not. 'Concept' is another word for 'idea'. Mugs are not ideas. We have the idea of a mug. But the mug itself is not an idea. Likewise for the mind. We have the idea of a mind. And minds have ideas. But minds are not ideas.

Moving on to minds, it just so happens that there are brains that have been medically split. — praxis

Er, no. Brains have been split. Minds, no. Again, what the hell do you mean by half a mind?

Those brain splitting cases actually underline - if underlining it needed - that minds cannot be split. If your brain is split and both hemispheres hooked up to waiting empty heads, where would 'you' go?

These are the options:

You'd sense or in some other way acquire information about the world through both. But there's still one 'you' right.

You'd go with one hemisphere and not the other. Still, only you.

You'd go with neither.

Those are the only conceivable options, yes?

I mean, here's a thought experiment for you. Let's say I owe you $1m. I then go and have half my brain removed and destroyed. Do I now owe you half a million?

No, right? I owe you $1m still. And that's because I haven't been split.

ll your life you've depended on your senses, never doubted them
— TheMadFool
Of course. What else could I do? These were and are my senses. What's the use or purpose doubting them? What could I gain from such a thing? In fact, if I did such a thing, on a constant basis, I wouldn't be able to write these lines, or any lines, for that matter. I would be living in an asylum! :smile:

normal mental state
— Alkis Piskas
How do we know that we are normal?
— TheMadFool
What's there not to undestand?
Normal = "Conforming to a standard; usual, typical, or expected" (Oxford LEXICO)
And I talked about our normal state, not normal state in general. Our personality, the basic characteristics of our behaviour and all that depend on and are dictated by our mental state. Which, i a sane person, is stable in general and under normal conditions. Not only ourselves but also others can recognize it. (I warn you: Don't ask me what do I mean by "normal conditions" because I won't answer it! :grin: — Alkis Piskas

Two points:

1. Skepticism (Are you sure?)

2. Plato's allegory of the cave (Who is normal?)

We have the idea of a mug. But the mug itself is not an idea. — Bartricks

Correct, the “mug itself” is not a mug without the idea of a mug.

minds are not ideas — Bartricks

I wrote that ‘mind’ is a concept.

Again, what the hell do you mean by half a mind? — Bartricks

I didn’t say anything about half a mind.

You'd sense or in some other way acquire information about the world through both. But there's still one 'you' right. — Bartricks

That’s about it, apparently. You seem to believe that a mind is only a mind if it possesses human self-awareness and identity.

I mean, here's a thought experiment for you. Let's say I owe you $1m. I then go and have half my brain removed and destroyed. Do I now owe you half a million? — Bartricks

Under the circumstances $500k seems fair to me.

I wrote that ‘mind’ is a concept. — praxis

The word 'concept' and the word 'idea' are synonyms. And mugs are not ideas. Think of a mug. That thought is an idea. It's not a mug. If you don't believe me, try and pour some tea in it.

I didn’t say anything about half a mind. — praxis

So be clear then: do you think minds can be divided? If you accept that they cannot be, then my argument goes through and you should agree that minds are not extended entities (and thus are not our brains - and so everything you said about dividing brains was irrelevant).

If you think they can be divided, then explain to me what the hell half a mind is.

That’s about it, apparently. You seem to believe that a mind is only a mind if it possesses human self-awareness and identity. — praxis

Er, where did I say that? What are you on about?

Under the circumstances $500k seems fair to me. — praxis

So I can reduce my debts by having bits of my brain removed. Okaay. What about a haircut?

Think of a mug. That thought is an idea. It's not a mug. If you don't believe me, try and pour some tea in it. — Bartricks

If my concept of a mug is not a mug then how can I reliably recognize mugs? I assure you I’m quite good at recognizing mugs. Maybe you don’t think I can tell the difference between a mug and an idea? Or perhaps you’re confusing my mental representation of a mug with my mental representation of an idea?

do you think minds can be divided? — Bartricks

I can appreciate Lizzie Schechter’s conclusion about split-brains, that “The impression that a split-brain subject has two minds is correct”, because I don’t think that a mind requires human self-awareness and identity. Please don’t ask me to repeat this again.

If my concept of a mug is not a mug then how can I reliably recognize mugs? — praxis

So if I recognize Tim because I've got a photo of him, Tim must be a photo?!? There's how one grasps and uses a concept and then there's what the concept is 'of'. These should not be confused. You are confusing them. The concept of a mug is not a mug. Have you tried pouring tea into it yet?

Maybe you don’t think I can tell the difference between a mug and an idea? — praxis

Yes, that is exactly what I think - and it is demonstrably true. You have stated several times now that mugs are concepts - ideas. They're not. We have the idea of a mug, but a mug is not an idea.

I have a photo of Tim. But Tim is not a photo. I have the concept of a mug. But a mug is not a concept.

You think it is, right? It isn't.

I can appreciate Lizzie Schechter’s conclusion about split-brains, that “The impression that a split-brain subject has two minds is correct”, because I don’t think that a mind requires human self-awareness and identity. Please don’t ask me to repeat this again. — praxis

Be clear: do you think minds can be divided?

Two points:
1. Skepticism (Are you sure?)
2. Plato's allegory of the cave (Who is normal?) — TheMadFool

How do these points answer my question "Should I be in a constant doubt of my senses"? Sould I doubt that I see a tree in front of me? Should I doubt about the existence of these exact words I am writing just now? I can't make it simpler than that. Sorry.

***

Re "Skepticism (Are you sure?)": Wouldn't that get into an endless questioning: "Are you sure you are sure?", "Are you sure you are sure you are sure?" ... :grin:

Re Plato's allegory: A very good allegory indeed. But Socrates talks here about higher levels of reality. The persons in the cave use the senses they have. They don't have other ones to chose from. That's all they have. To trust them or not makes absolutely no sense. (All of us have jumped to a lot of levels of reality in our life. But in each new level, and for the period it lasts, that's all we have. We can't do otherwise. Except continuing our way up to higher levels ... )

BTW, both your points, esp. skepticism, refer to knowlegde, in general. Nothing to do with senses, which is our subject! (This is what can happen when one gets trapped into a position that he cannot defend anymore: he changes subject! And, honestly, I don't like that. It's not fair, esp. for thinking people and in philosophical discussions.)

To trust them or not makes absolutely no sense. — Alkis Piskas

That's why :point:

I don't mean to burst your bubble and I know this is hard but [...] — TheMadFool

Well, you still didn't burst my bubble and it was still not hard! (Or maybe, did it turn as a boomerang against yourself? :smile:)

For me, this is just a discussion, which, besides other things, makes me know you better! :smile:

If I look to your brain I can nothing but conclude that the thinking you perceive finds place inside the brain inside of you. YFor you, on the other hand, thinking finds place inside of you. Not inside your brain.

Well, you still didn't burst my bubble and it was still not hard! (Or maybe, did it turn as a boomerang against yourself? :smile:)

For me, this is just a discussion, which, besides other things, makes me know you better! :smile: — Alkis Piskas

You contradict yourself, a telltale sign that it is beyond your ken. Don't worry, we're in the same boat. It's extremely difficult to break a habit that we've developed even before we could think properly i.e. from infancy and reinforced over a lifetime.

A simple question should get the point across: Is depression really an illness? Is there joy enough in this world to be happy, let's even lower the bar, content or is it the other way round? Think about it. Either this shocks or it won't. If it does, I've done my job and if it doesn't then, too bad, you're like some of those folks who had only seen white swans in their life and come to the conclusion there are no black swans.

I mean, here's a thought experiment for you. Let's say I owe you $1m. I then go and have half my brain removed and destroyed. Do I now owe you half a million?

No, right? I owe you $1m still. And that's because I haven't been split. — Bartricks

Slight digression, but a similar thought experiment. Suppose someone gave you a bunch of shit, then said you liked it so you owe them, then destroyed half your brain as repayment, then tortured you until you die from it, would you owe them half a million dollars? Certainly not $1m! (Bonus question: what if this was all caused before you were born?)

A person thinks. Not a brain.

I've never seen a brain think, or reflect or cognize. But people, on the other hand, do all these things. — Manuel

This is clearly the right starting point. (I don't agree that it answers the question, but I'm not sure the question is a good one.)

Minds causally interact with the sensible world. That much seems clear to everyone. — Bartricks

No it does not.

I, a person who has a mind, causally interact with the sensible world. You, another person with a mind, causally interact with the sensible world. @Manuel has this right. We can do so because we also have bodies, each a particular body that is ours and no one else's. But "my mind" and "my body" are me considered only in certain aspects -- that is, they are abstractions. I, a person, am the concrete particular. A body without a mind is not a person; a mind without a body is at best an hypothesis, at worst a superstition.

The concept of a mug is not a mug. — Bartricks

I have a good mental representation of a mug, if I may say so myself, and I can assure you that it’s a mug and not a piano or whatever.

Have you tried pouring tea into it yet? — Bartricks

I’ve imagined it, just as you are now imagining it.

Be clear: do you think minds can be divided? — Bartricks

You talk about half a mind and a divided mind. Split-brains, to my mind, are a good example of a divided mind. It just so happens that there are also people with half a brain.



Going back to your mug, if I cut it in half horizontally the bottom half will still be a functional mug, though it will have half the capacity and the handle won’t work so great.

You talk too much! :smile:

Clearing up the issue may help formulate the question. :wink:

You talk too much! :smile: — Alkis Piskas

Yes, I've often been told that.

That's half a brain. Christ. This clearly isn't going to be fruitful.

What on earth are you on about?

That's half a brain. — Bartricks

Which is similar to half a mug. Half a mug is a diminished (loss of capacity & function) mug, right? Half a brain is a diminished (loss of capacity & function) mind, is it not?

What on earth are you on about? — Bartricks

It's a long story lol

The reference to Bishop Berkeley came up a while ago and Bartricks knows about it. I would expect Bartricks would like to pay his debts in Berkeley Dollars.

Is that what you're working with? Listen Halfy, physical things can be divided. Minds can't. Therefore minds are not physical things.
A mug half full is not half a mug. You think less than I do. That doesn't mean you're less of a mind than I am.

What are you on about. I, a person, am my mind and I interact with the sensible world. So causation takes place between my mind and the sensible world.

Now, if my sensations are giving me an awareness of a physical world, then causation is taking place between my mind and a physical realm. Which, as my mind appears in numerous ways demonstrably to be immaterial and not physical,would be evidence that causal transactions are possible between radically different kinds of thing.

On the other hand, if we have independent reason to think no causal transactions can take place between radically different kinds of thing, then the fact my mind interacts with the world my sensations are telling me about constitutes evidence that such a place is mental and that I am interacting with another mind rather than with a realm of extended objects.

It is only the narrow minded and dumb who think causal interaction is evidence of the mind's physicality. And I case Praxis reads this, minds cannot actually be narrow.

I, a person, am my mind — Bartricks

No need to repeat the entire argument. This was plenty.

What does it mean? Is it English?

If you are your mind, then I can substitute "Bartricks's mind" for "Bartricks", salva veritate.

"Bartricks's mind has just made another post in this thread."

I take it you believe that is a reasonable thing to say.