:up: :ok:

I just want to run this by you for your opinion.

You're right about the translation of "cogito ergo sum" as "thinking, therefore being". All Descartes claimed was proof of a "thinking thing". I want to take it a step further, if it hasn't been done already, by showing that this "thinking thing" can't be a material/physical entity with the aid of the fact that everything physical/material is dubitable i.e. the physical/material could be an illusion. If the physical/material could be an illusion, it can't be that the "thinking thing" Descartes proved as real is a physical/material because that leads to the contradiction the "thinking thing" is real AND the "thinking thing" could be an illusion (the physical/material).

Perhaps we need to consider what we mean by saying that the physical could be an illusion. We're aware of physical reality by a single means - through our senses. It is possible that our senses are being deceived or that we're hallucinating everything. Thus, it's possible that physical reality is an illusion, a hallucination. Ergo, everything physical is doubtable in re realness.

The Cartesian "thinking thing", however, is real and to doubt it is to confirm it (as the doubter). The question that naturally follows is whether this "thinking thing" is physical or non-physical. It can't be physical for the simple reason that the physical could be an illusion but we know the "thinking thing" is not all illusion.

1. All physical things are things that could be illusions
2. No "thinking things" are things that could be illusions
Ergo
3. No physical things are "thinking things"

What do you think?

That pretty well recapitulates Descartes' argument. If you read through the meditation where he develops this idea - the very first thing I read in formal philosophy studies! - then that's close to what he says.

The possibility of the world as a grand illusion is not a new idea in philosophy, either, but has been entertained for as long as philosophy has been contemplated. However Descartes' approach is very rigourous and thorough.

He goes on from that foundation to develop his doctrine of 'clear and distinct ideas'. I'd have to brush up the details, but I think he was driving at, in particular, mathematical concepts, which are capable of a far higher degree of clarity and distinction than, say, your happiest childhood memory, or what you like about New York (or whatever). By that means, being a Rationalist, Descartes wishes to assemble a kind of indubitable rational structure. No coincidence that Descartes is for this reason regarded as one of the founders of modern scientific method. He devised algebraic geometery, after all, which is fundamental to many of the sciences.

The problem with Descartes' conception of res cogitans was precisely that it was conceived of as a 'thinking thing'. And the reason that is a problem, is because it objectifies 'the thinking being' as something objectively real. And I don't think it is that - I think it transcends the subject-object distinction, because it is the very being within which the subject-object relationship arises in the first place - a critique which Husserl elaborates in his Crisis in the European Sciences ('Husserl regarded this objectivism as one of the greatest tragedies to befall philosophy' ~ ref). But the upshot is, I agree with your conclusion - that the notion of 'thinking things' is self-contradictory.

That there's an illusion means there's something, the mind, that perceives this illusion. — TheMadFool

thank you.

Kaarlo Tuomi

:up: :ok:

1. All physical things are things that could be illusions
2. No "thinking things" are things that could be illusions
Ergo
3. No physical things are "thinking things"

Premise 1 seems to be a contradiction, since under one understanding of "physical" things that are physical simply by definition are not illusions. The argument might need to be rephrased as
1. Anything that can be taken to be physical could be an illusion.
2. No thinking things are illusions
3. Thinking things cannot be taken to be physical things.

However, the argument thus stated does not rule out the possibility that thinking things are physical things, just that they cannot be taken to be such. Materialist philosophers love to point out this kind of epistemological/metaphysical distinction, as if it were clear cut. Anyway, to get to a conclusion that thinking things are not physical things, you would need an extra premise to the effect that if something is F then it can be imagined/conceived/taken to be F, which might be a little difficult to defend.

See my reply to hwyl above. If there's some kind of deception going on, it follows there's something that's being deceived and that's the thinking part. The skepticism is universal but the thing is to be skeptical implies the existence of a skeptic. — TheMadFool

What does this have to do with the material vs. Immaterial distinction? I asked what the difference was between them. You can claim to be a doubter, but what makes doubting immaterial and the world material? I wasn't asking if thinking exists or doesn't. I was asking what makes something immaterial which you claim makes material things nonexistent. If you are a doubter, then why not doubt that the mind is immaterial - whatever that means? Why couldn't I just say that the mind is material and therefore material things exist and the immaterial world doesn't exist, because you haven't defined what it means to be immaterial or material.

now explain how Descartes is able to prove, in your own words, "beyond the shadow of a doubt," that the voice he can hear is his? — Kaarlo Tuomi

It doesn't matter. Something exists that hears voices. By convention this something is called "I" in English. You can call it Tartenpion if you want to.

Premise 1 seems to be a contradiction, since under one understanding of "physical" things that are physical simply by definition are not illusions. — jkg20

If you speak of such things as "under one understanding", you draw a distinction between one sense of a word/term and another. Ok, although I'd like to know, if possible, what the various senses of meaning there are for "physical".

Google definition of "physical":

1. relating to the body as opposed to the mind.

2. relating to things perceived through the senses as opposed to the mind; tangible or concrete.

I'm focusing my attention on 2, but do include 1 in this, specifically the part where it says "perceived through the senses" and we know the senses are unreliable (think hallucinations) and can be deceived; if so, the physical could be an illusion.

I was asking what makes something immaterial — Harry Hindu

Please read my reply to jkg20 and Wayfarer.

1. All sensory perceptions are things that could be illusions

2. All physical things are sensory perceptions

Ergo

3. All physical things are things that could be illusions

4. No "thinking things" are things that could be illusions

Ergo

6. No "thinking things" are physical things

7. All "thinking things" are non-physical things (6 obversion)

8. All non-physical things are immaterial things

Ergo

9. All "thinking things" are immaterial things

I was asking what makes something immaterial which you claim makes material things nonexistent — Harry Hindu

Good question. I've been asking the same question to others without getting a proper answer. I guess you could say that an immaterial thing is something that can't be perceived through the senses in the way our bodies are. The immaterial then lacks all the properties that we assign to the material/physical e.g. the familiar qualities of mass and volume of matter are absent from the immaterial world.

One issue I have difficulty with is the meaning of "exist" when applied to the immaterial. The definition of "existence" is intimately tied to perception through the senses and perception through the senses has a deep association with the physical with the end result that it becomes difficult, if not impossible, to talk of existence without referring to the physical. Given this is the case, what could existence mean when used on the immaterial? What does it mean when I say that an immaterial "thinking thing" exists? A way out, the only way out perhaps, is to say that immaterial things are things that can't be perceived through the senses but are as "real" as the things that can be perceived through the senses, the physical world. Why don't you have a go at a definition of "exist" that includes the immaterial?

Given that we can cast doubt on the reality of the physical — TheMadFool

All the particulars of the physical, but not any physical whatsoever. One cannot imagine experiencing nothing at all — that is simply to not imagine — and the physical world just is the world of experience, so one cannot imagine there being no physical world at all, only that all the particulars one believes about the physical world should turn out to be different.

The stuff about the identity of the doubter is just a parallel to that. We can’t imagine being nobody to experience anything, and we can’t imagine not experiencing anything, so indubitably someone exists to experience and something exists to be experienced, even though all of the details of both of those are dubitable.

I want to take it a step further, if it hasn't been done already, by showing that this "thinking thing" can't be a material/physical entity with the aid of the fact that everything physical/material is dubitable i.e. the physical/material could be an illusion. — TheMadFool

That has been attempted already, by Descartes himself. It’s the whole foundation of Cartesian dualism.

That has been attempted already, by Descartes himself. It’s the whole foundation of Cartesian dualism. — Pfhorrest

Any ideas how Descartes argued for a non-physical "thinking thing"?

something exists to be experienced — Pfhorrest

This is questionable. There is no necessity for the physical - it could be an illusion.

Any ideas how Descartes argued for a non-physical "thinking thing"? — TheMadFool

Pretty much exactly how you did. "I can doubt that there is anything physical, but I can't doubt that I exist, so I can't be just a physical thing".

There is no necessity for the physical - it could be an illusion — TheMadFool

All of the particulars of it could be an illusion, but so could all the particulars of yourself. That there is something you are experiencing at all cannot be doubted, and more than you can doubt that someone is doing the experiencing; and the physical world just is the world that is accessible to experience, as opposed to supernatural things that are not amenable to experience.

I made a long post explaining this earlier in this thread, I'll quote it here again since I keep repeating this summary of it...

Descartes famously attempted to systematically doubt everything he could, including the reliability of experiences of the world, and consequently of the existence of any physical things in particular; which he then took, I think a step too far, as doubting whether anything at all physical existed, but I will return to that in a moment. He found that the only thing he could not possibly doubt was the occurrence of his own doubting, and consequently, his own existence as some kind of thinking thing that is capable of doubting.

But other philosophers such as Pierre Gassendi and Georg Lichtenberg have in the years since argued, as I agree, that the existence of oneself is not strictly warranted by the kind of systemic doubt Descartes engaged in; instead, all that is truly indubitable is that thinking occurs, or at least, that some kind of cognitive or mental activity occurs. I prefer to use the word "thought" in a more narrow sense than merely any mental activity, so what I would say is all that survives such a Cartesian attempt at universal doubt is experience: one cannot doubt that an experience of doubt is being had, and so that some kind of experience is being had.

But I then say that the concept of an experience is inherently a relational one: someone has an experience of something. An experience being had by nobody is an experience not being had at all, and an experience being had of nothing is again an experience not being had at all.This indubitable experience thus immediately gives justification to the notion of both a self, which is whoever the someone having the experience is, nd also a world, which is whatever the something being experienced is.

One may yet have no idea what the nature of oneself or the world is, in any detail at all, but one can no more doubt that oneself exists to have an experience than that experience is happening, and more still than that, one cannot doubt that something is being experienced, and whatever that something is, in its entirety, that is what one calls the world.

So from the moment we are aware of any experience at all, we can conclude that there is some world or another being experienced, and we can then attend to the particulars of those experiences to suss out the particular nature of that world. The particular occasions of experience are thus the most fundamentally concrete parts of the world, and everything else that we postulate the existence of, including things as elementary as matter, is some abstraction that's only real inasmuch as postulating its existence helps explain the particular occasions of experience that we have. — Pfhorrest

Or to quote from an essay I wrote in college:

The root of this problem is that I can only conceive of that which I could hypothetically perceive. That is to say that, if asked to conceive of something with no perceptual qualities, I am as unable to do that as I am unable to conceive of square circles — I don’t even know where to begin trying. So, as Descartes’ description of this thought experiment has no perceptual qualities different from the real world, it seems that all I am conceiving of is just the real world itself. But let us attempt, for the sake of charity, to put some more effort into conceiving of a situation where all my normal perceptions are false.

I could perhaps conceive of the real world, plus the ostensible belief that all of my perceptions are false. That is, I could conceive of myself apparently here in my room, writing this essay, and being disposed to say things like “all perception is deception”, or thinking those words, or agreeing with such statements. I can imagine how I might behave if I believed such a thing, other thoughts that I might think because of those beliefs, and so forth. Perhaps I would, as a result of those beliefs, become a religious person and start to attend church regularly. But as things in themselves, separated from our experience or perception of them, by definition have no perceptual qualities (being so separated from them), I cannot conceive of such things directly, and thus I cannot “clearly and distinctly” conceive of it being the case that something is in fact true or false. I can only conceive of what such a thing might look, sound, smell, taste, or feel like, and in this case the only differences as such between this conceived world and the real world are differences in my own behavior. It seems that all I have conceived here, and thus, all I have shown to be logically possible, is that I could believe that my experiences are entirely deceptive.

That is non-controversial, as anyone can believe practically anything they want, and showing that a belief is possible — merely that it would be possible to believe something, not that the thing believed is itself possible — is not helpful to Descartes’ argument.

Let’s try this again then, another attempt to conceive of all of my perceptions being false.

I suppose that I could conceive of myself apparently here in this room, writing this essay, and then suddenly, all my perceptions stop. I lose all vision, hearing, senses of touch and taste and smell, even my sense of kinesthesia or proprioception, even the residual images in my eyes and the sound of my own blood flowing in my ears. I imagine that I utterly cease to experience anything. But in conceiving of such a thing, it seems that all I am conceiving of is nothing at all.

As I can only conceive of things which I could perceive, when I conceive of not perceiving anything I have simply stopped conceiving entirely. This lack of conception — not inconceivability, but simply willful lack of conception — clearly does not prove anything. So let us modify this thought experiment. I do not imagine that this is what Descartes had in mind, but I feel obligated out of charity to give my best support to his argument, and in doing so thoroughly dismiss it when it still fails.

So I will now imagine that I am sitting here in this room, writing this essay, when suddenly my vision grows dark, my ears ring out into a dull monotone, my skin grows numb, and my sense of balance and space becomes skewed. Then my senses become refined again, and I find myself lying on a floor in a vast dark room, with a small, lanky, muscled figure grinning an evil grin at me. I imagine that he tells me that he is The Evil Genius, and that all of my experiences up until and including this very moment as I lie here before him are and always have been entirely false, that there is no material universe, and he and I are all that exists, utterly disembodied — even his visage before me now is a deception, as even he has no physical form. I imagine then that he tells me he will now return the normal stream of experiences, and I feel the sensation of rushing through the darkness above me as the little figure recedes into the distance and vanishes, and suddenly I feel a hard jolt as I am once again in my chair.

I imagine that I would then begin to wonder who had laced my food with drugs this evening. And I would be right to doubt the veracity of that experience, as even Descartes would agree, although for different reasons. I would doubt it because, on the surface, it seems utterly incompatible with my other experiences, and would require either a fantastic explanation such as those to be described below, or a more mundane explanation such as hallucinogenic drugs. In short, I can agree with Descartes at least that any individual experiences, or at least our interpretations thereof, are dubious. Descartes would likely doubt such a thing because he finds experience on the whole to be dubious. Either way, this imaginary me would find himself doubting the veracity of these extraordinary experiences, and though perhaps they might be the thing which planted the notion of universal deception in his mind, the fact remains that all that I am imagining when I conceive of this doubtful self is the possibility that I might, for some reason, believe all my experiences to be false. I still have not directly conceived of my experiences being false, and thus have not proven that to be logically possible. At this point I can still find no means by which to doubt that some material universe exists, even though my beliefs about the specifics of that material universe are dubious.

But I can imagine a situation which could demonstrate with irrefutable mountains of evidence that all my experiences up to the point of revelation had been false. I can imagine that as I sit here writing this, I once again become blind, numb and disoriented and wake up in a room with this lanky Evil Genius, yet instead of returning me to my normal set of experiences, he takes me out of this large dark room and shows me the world as it really is. I can imagine seeing nightmarish landscapes and ominous buildings, and being told that I am to live here now until I die, for he and I are the only people in this desolate world, and everything up until now has been signals fed into my brain to allow me to believe that I was living a life on Earth. I can even imagine that I am not human, that I have a small form like his, as we are perhaps the last of some dying alien race. Perhaps Earth and humanity never existed and were merely a fantasy conjured up to spare me this hideous existence. I concede that it is entirely conceivable, and thus logically possible, that the world which I am in fact experiencing right now is not the real world. But even in conceiving this, I have not conceived that the physical world does not exist. Merely, I have conceived that the physical world is nothing like what I thought it was. But still I am conceiving of it existing. I can even conceive that the above world might itself be a deception, that perhaps I am a really brain in a vat being experimented on by scientists. Perhaps those scientists and my vat are themselves not real, and that entire world is in fact inside the Matrix. I can imagine as many layers as I like, but at some point I must always conceive that some physical world exists.

To do otherwise is simply to conceive nothing, as shown earlier, which does not prove anything.

It seems that I simply cannot conceive of no material world existing at all. — Inconceivable, or: You Keep Using That Word, I Do Not Think It Means What You Think It Means

nd also a world, which is whatever the something being experienced is. — Pfhorrest

one cannot doubt that something is being experienced, and whatever that something is, in its entirety, that is what one calls the world. — Pfhorrest

Well, it all turns on the nature of experience. In my humble opinion there are three parts to experience which I'll explain with sight and a flower:

1. The experiencer (sentient beings with eyes)
2. Experiencing (seeing the flower)
3. That which is experienced (the flower seen)

Descartes accepts the truth of 2, experiencing, but he realized that 2, experiencing, could occur without 3, that which is experienced, as when an evil demon manipulates our minds which I assume is Descartes' way of saying that experiencing is possible without 3, that which is experienced: we could see a flower even when there's no flower at all.

When I talk of the physical, the material world, I'm referring to existence of 3, that which is experienced, independent of both 1, the experiencer, and 2, experiencing. Since 2, experiencing, is possible without 3, that which is experienced, it follows that 3, that which is experienced, the flower, could be an illusion, unreal, the evil demon playing tricks on 1, the experiencer.

Of the 3 parts of experience, Descartes' cogito ergo sum proves, with 100% certainty, the reality or the existence of 1, the experiencer. 2, experiencing, is self-evident to all. What's neither self-evident nor inferable is 3, that which is experienced, as existing without 1, the experiencer, and 2, experiencing.

My point is that even if you're not actually experiencing a flower, your experience of what seems to be a flower is still an experience of something. People mis-perceive all the time, but perception is not sensation. You're sensing something, even if your perception of what that something is, is wrong.

So you can't really have 2 without 3, you can just have 1 misinterpret 2 to get at the wrong 3, but there's still some 3 or another that 2 is the experience of.

still an experience of something — Pfhorrest

I understand what you mean: you identify experiencing with that which is experienced as the following statement

So you can't really have 2 without 3 — Pfhorrest

indicates.

My question is how do you explain hallucinations which are instances of 2, experiencing, without 3, that which is experienced?

More importantly, how can you prove, with certainty, that our senses are 100% reliable, which you must if you believe that "you can't really have 2 without 3"?

2. relating to things perceived through the senses as opposed to the mind; tangible or concrete.

I'm focusing my attention on 2, but do include 1 in this, specifically the part where it says "perceived through the senses" and we know the senses are unreliable (think hallucinations) and can be deceived; if so, the physical could be an illusion.

Note the "tangible or concrete" in definition 2. Things which are tangible and concrete are generally put in opposition to those that are merely illusory.

2. All physical things are sensory perceptions

No materialist is going to accept this premise. The most you will get them to accept is that physical things can be objects of sensory perceptions.

Things which are tangible and concrete are generally put in opposition to those that are merely illusory. — jkg20

Agreed but I didn't contest that.

No materialist is going to accept this premise — jkg20

That means the statement "all physical things are sensory perceptions" is false which implies the truth of the statement: some physical things are not sensory perceptions. Please name some.

That means the statement "all physical things are sensory perceptions" is false

No, it means it might be false and certainly a materialist is going to claim that it is false.

some physical things are not sensory perceptions. Please name some.

I'm not a materialist, I invite those who are to respond fully. However, let's kick the ball rolling by offering up "the football in my shed". Seems like a reasonable candidate to me. After all, when I look at the football in my shed there might be a sensory perception of that football, but that does not entail that the football is that sensory perception.

No, it means it might be false and certainly a materialist is going to claim that it is false. — jkg20

Prove it. Sorry. Ok

I'm not a materialist, I invite those who are to respond fully. However, let's kick the ball rolling by offering up "the football in my shed". Seems like a reasonable candidate to me. After all, when I look at the football in my shed there might be a sensory perception of that football, but that does not entail that the football is that sensory perception. — jkg20

Physical definition: relating to things perceived through the senses as opposed to the mind; tangible or concrete. — TheMadFool

Is the following argument better?

1. All physical things are things perceived through the senses

2. All things perceived through the senses are things that could be illusions

Ergo,

3. All physical things are things that could be illusions

4. No thinking things are things that could be illusions

Ergo,

5. No thinking things are physical things

The problem with your argument is that materialist believe matter is not an illusion!

The problem with your argument is that materialist believe matter is not an illusion! — Gregory

Matter could be an illusion.

Their position says it can't be an illusion lol

If matter is an illusion, then ye the mind is not material. That's axiomatic

Their position says it can't be an illusion lol — Gregory

What's their argument?

It's their premise so your argument doesn't work. It's a consistent position

It's their premise so your argument doesn't work. It's a consistent position — Gregory

So, if I take a proposition, even a controversial one, as a premise, it shuts down the opposition? I could make atheism cease to to "work" by making "god exists" a premise. :chin:

Materialist don't agree with your premise so the argument fails

But the "certainty" Descartes arrives at isn't knowledge! KILPOD - knowledge implies the logical possibility of doubt.