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

Please explain.

Something potentially exists; Something experiences this potential and exists in relation to it. Everything else is a relational construct derived from applying the scientific method in iterative cycles. Descartes’ statement of certainty is subjective, and therefore potential at best.

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

Is Descartes' position justified or not?

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. — TheMadFool

1. Isn't the mind part of the body, or are you saying that your body is an illusion? If so, then what is the cause of your pain when you experience it?

2. Other minds are perceived through the senses, therefore other minds are part of the illusion and all you are left with is solipsism.

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 — TheMadFool

By what means are you aware of your own mind if not by sensing it? What does "perceived" mean? In what manner are you aware of your thinking? What form does thinking and perceiving take to say that you perceive your mind?

Is Descartes position justified or not?

Absolutely not. His big mistake is to think that a foundation of indubitable certainty is required for knowledge. The kind of indubitable certainty he finds in the privacy of his own mind rules out the possibility of discovery, which is a necessary condition for knowledge. What Descartes takes to be knowledge is nothing of the sort, precisely because it rules out the logical possibility of doubt.

Interesting. So your claim is that if a proposition can be known, then it can be doubted. What about a proposition such as "No ant is an elephant"? Is there a way of doubting this? Obviously I mean more by "way of doubting this" than just uttering the expression "There might be an ant that is also an elephant". The doubt has to have some substance. If there is no substantive way to doubt it, does that mean it is not knowable as a proposition?

What about a proposition such as "No ant is an elephant"? Is there a way of doubting this?

Well yes, the logical possibility of doubt exists here, because to know that no ant is an elephant it's necessary to know what an ant is and what an elephant is. These are cognitive achievements. If it's (logically) possible to doubt what an ant is or to doubt what an elephant is, then it's (logically) possible to doubt that no ant is an elephant. Descartes would certainly have said that this sort of proposition can be doubted, which is why the Cogito arrives at the proposition that it does. But for Wittgenstein, "No ant is an elephant" would count as knowledge, because the possibility of doubting it is logically possible. Ants and elephants are things to be discovered in the world.

But how, knowing what "no ant is an elephant" means, is it possible to doubt it? Sure I may not know the meaning of "ant" and/or I may not know the meaning of "elephant" but then I simply do not understand the proposition that no ant is an elephant, it might just as well be the statement that no figgy is a wiggy. Once a proposition like that is understood is it possible to doubt it? For instance, I understand the proposition that ants run in circles when injected with amphetamines. I can also doubt it, since for all I know about ants they can are unaffected by amphetamines. This marks a distinction between kinds of proposition. Now, whether that is a distinction in kind or in degree or not is another matter.

Well yes, the logical possibility of doubt exists here, because to know that no ant is an elephant it's necessary to know what an ant is and what an elephant is. — Bunji

And how do you justify the proposition that things are not simply what is meant?
I can just say "that" is definitely not "this". Just look at the letters THAT THIS. You see the difference, right? What is different cannot be the same. It requires changing the subject from the concrete thing in question to it's essence to doubt this. But why would I want to change subjects?

But how, knowing what "no ant is an elephant" means, is it possible to doubt it? Sure, I may not know the meaning of "ant" and/or I may not know the meaning of "elephant" but then I simply do not understand the proposition that no ant is an elephant...

But it is precisely the meaning of "no ant is an elephant" that is open to the logical possibility of doubt! Knowing what the terms "ant" and "elephant" mean is integral to knowing whether this or that is an ant or an elephant. The word "ant" happens to refer to a certain type of insect, and "elephant" to a certain type of large, ruminant mammal, but it might have been otherwise (that it might have been otherwise is a logical possibility). It is logically possible that there might have been a type of ant called an "elephant", where the "ant" element of the word refers to an ant and the "eleph" prefix is a technical description of the type of ant it is. You know very well (as do I) that this is not the case, but that does not alter the logical possibility it might have been. You and I know that snow is white, but the logical possibility remains that it might not have been. (KILPOD = knowledge implies the logical possibility of doubt).

For Descartes, this logical possibility of doubt means that we don't actually know that "no ant is an elephant". Hence, the Cogito takes us beyond empirical propositions like that to a level of "certainty" that is logically immune to the possibility of error. Even if all my thoughts are false, including the belief that no ant is an elephant, the very fact that I think at all proves that I do at least I think. And I cannot think without existing, so all the while I think I must exist. I cannot doubt that I think, since to doubt that I think is to think.

But for Wittgenstein, this solipsistic elimination of the logical possibility of doubt eliminates the possibility of knowledge itself, because it takes us beyond the bounds of sense. What cannot even in principle be wrong cannot be right either. Language itself would gain no traction because no rules for the determination of meaning could be generated. Hence, contrary to Descartes, we do know that "no ant is an elephant" as well as we know anything. Such a proposition is part of our "world picture"; part of "the inherited background against which I distinguish between true and false". But that is only because what happens to be true might have been false, and vice versa.

And how do you justify the proposition that things are not simply what is meant? I can just say "that" is definitely not "this". Just look at the letters THAT THIS. You see the difference, right? What is different cannot be the same. It requires changing the subject from the concrete thing in question to it's essence to doubt this. But why would I want to change subjects?

The subject here is Cartesian doubt, which I am not trying to justify. Quite the reverse. According to Descartes the only certainty I have about THAT THIS is that I am aware of an image which appears to me as THAT THIS. It's open to doubt (according to Descartes), whether there is anything outside my own mind corresponding to the image (e.g. a computer screen with THAT and THIS written on it). It seems to me there's a difference between THAT and THIS, but my eyes could be deceiving me, or I could be imagining a difference that isn't really there, or I could be dreaming. These are all logical possibilities. But that doesn't mean they are real, sensible possibilities. I agree with Wittgenstein that entertaining such doubts is nonsensical; it undermines the very possibility of meaning, truth and knowledge. So I agree with you that the difference between THAT and THIS is as obvious as anything is. It makes no sense to doubt it. It is so manifestly obvious that it lies "outside the route of enquiry", as Wittgenstein would say. To say "I know that THAT is not the same as THIS" seems somehow ridiculous. It's the sort of knowledge that is so taken for granted that it wouldn't usually occur to us to claim it as knowledge. But it is still open to the logical possibility of doubt.

The case of "no ant is an elephant" is more complicated because reference is being made to things outside the words "ant" and "elephant" themselves. Just because there is a manifest difference between the words doesn't mean (necessarily) that there is a difference between the things that the two words refer to. It's a logical possibility that they could have referred to the same things, even though, in fact, they don't. This has nothing to do with essences. It has only to do with the distinction between what is in fact the case and what is logically possible.

According to Descartes the only certainty I have about THAT THIS is that I am aware of an image which appears to me as THAT THIS. — Bunji

And this already is where he changes subjects. He is not aware of the words anymore but silently makes the proposition those are perceived images. This changes the nature of things. But where did he get that undoubtable insight?
We know for sure there is THIS and there is THAT. And we know they are different.

It seems to me there's a difference between THAT and THIS, but my eyes could be deceiving me, or I could be imagining a difference that isn't really there, or I could be dreaming. — Bunji

Again, that is talking metaphysics. You do not take the things as they are anymore, but subsume them under some essence. But how would an assumed essence make THIS and THAT identical?

Therefor:

To say "I know that THAT is not the same as THIS" seems somehow ridiculous. It's the sort of knowledge that is so taken for granted that it wouldn't usually occur to us to claim it as knowledge. But it is still open to the logical possibility of doubt. — Bunji

No. The ability the differentiate the two is an obvious indicator of their difference. If you have
A = A and say "but in this case the A was a B" this leads to B = B. It is still the same. Even if I (obligingly) wrote A=B with "B not= A" this would only prove that such a thing cannot be - logically.

The word "ant" happens to refer to a certain type of insect, and "elephant" to a certain type of large, ruminant mammal, but it might have been otherwise (that it might have been otherwise is a logical possibility).

This seems a little beside the point. The sentence "Ants are not elephants" might have expressed a different proposition to the proposition that it actually expresses. No one is denying that, why would anyone deny it? But admitting that is not the same things as admitting the possibility of doubt concerning the proposition that the sentence actually does express. It is merely to allow the possibility that words used to express that proposition may have meant things other than they actually do. That is not doubt, that is just accepting alternative linguistic possibilities.

In any case, if you are attempting to lay down a necessary or sufficient or necessary and sufficient condition for what counts as knowable, you are not being very Wittgensteinian, at least not under one interpretation of what Wittgenstein was trying to do.

In conclusion, we can be certain of only one thing - the existence of minds - and we can always doubt the reality of the physical world, materialism. — TheMadFool

Matter is not real anyhow. At least not in the naive way our senses lead us to believe. A hydrogen atom is only a geometric condition that energy happens to be in. All that is really there is energy. The physical atom is only an image, a conjuring trick. A sophisticated trick but a trick nonetheless. Likewise with all physical things; they are a condition, not a substance. Reality is energy and mind.

By what means are you aware of your own mind if not by sensing it? What does "perceived" mean? In what manner are you aware of your thinking? What form does thinking and perceiving take to say that you perceive your mind? — Harry Hindu

It seems to me that none of the five senses are required to make us aware of our minds. The mind is conscious over and above the senses. In fact the senses are only a crude imitation of consciousness. Real consciousness is of the mind.

It seems to me that none of the five senses are required to make us aware of our minds. — EnPassant

Then by what means are you aware of your mind? What does it mean to say that you are aware of your mind? What is the relationship between you and your mind? Thinking takes the same form that your senses provide. To say that you are thinking about your trip to the lake means that a visual, auditory and tactile image of the trip to the lake takes form in your mind. If the world is an illusion, then so is thinking.

What would be the nature of Descartes demon? Is the demon not part of the world that is doubted to exist? Does not Descartes doubt the cause of his own doubt away?

It's not the senses that should be doubted. They work just as they were designed to work. It is our interpretation that should be doubted. Mirages don't go away when we realize what they are. They still persist. It's just that we now have a proper interpretation for why they exist and what causes them, to where it is predictable - it no longer is an illusion, but what is expected to happen thanks to the nature of light and how it interacts with our eyes.

1. Isn't the mind part of the body, or are you saying that your body is an illusion? If so, then what is the cause of your pain when you experience it? — Harry Hindu

The crux of Descartes' argument is that everything physical, that includes the body, could be an illusion. The experience of pain can't be thought of as deserving a special status, as I reckon you're implying, different from other sensations or sensory perceptions. The fact that people can hallucinate in visual, auditory and tactile modalities should inform you that all sensations, including pain, could be illusions.

By what means are you aware of your own mind if not by sensing it? What does "perceived" mean? In what manner are you aware of your thinking? What form does thinking and perceiving take to say that you perceive your mind? — Harry Hindu

I'm aware of my own mind through thinking: I think therefore, I am. The mind becoming aware of itself in Cartesian self-reflective fashion is distinct from sensory perception in the sense that in the former there's no intermediary, no middle man so to speak, the mind sees itself through itself, but in the latter, our senses are interposed between our minds and the so-called physical, if it even exists.

Absolutely not. His big mistake is to think that a foundation of indubitable certainty is required for knowledge. The kind of indubitable certainty he finds in the privacy of his own mind rules out the possibility of discovery, which is a necessary condition for knowledge. What Descartes takes to be knowledge is nothing of the sort, precisely because it rules out the logical possibility of doubt. — Bunji

I'm only concerned about the cogito ergo sum argument. Is it a sound argument or not?

Thinking takes the same form that your senses provide. — Harry Hindu

What about abstract thought? If you have a pain in your foot and you go to the doctor s/he might tell you that the pain is not really in your foot at all, it is in your brain. Why then, you could ask, does the pain seem to be in your foot? The doctor might go on to say that the brain contextualizes the pain and 'places' it in your foot. But it is not really in your foot...

But this argument can be extended to the mind: the pain is not really in your brain either, it is in your mind. From this it can be argued that the entire physical body is no more than a context; a physical context in which the mind experiences. In fact the entire brain-body-senses context is a physical context in which the mind's experiences are framed. But the mind can also think independently of the bodily context, as The Mad Fool points out.

I'm only concerned about the cogito ergo sum argument. Is it a sound argument or not?

"I think, therefore I am", is not a logically valid argument. To be valid it would need to take the form "If I think, then I exist. I think, therefore I exist." (modus ponens). If the premises of this argument are true, then the conclusion must also be true, but that is a mere tautology. The conclusion doesn't tell us anything more than the premises already tell us, so it doesn't give us any knowledge. Since the purpose of the Cogito argument is to provide a sound foundation of knowledge, it fails in that purpose even when transposed into a valid argument.

"I think, therefore I am", is not a logically valid argument. To be valid it would need to take the form "If I think, then I exist. I think, therefore I exist." (modus ponens). If the premises of this argument are true, then the conclusion must also be true, but that is a mere tautology. The conclusion doesn't tell us anything more than the premises already tell us, so it doesn't give us any knowledge. Since the purpose of the Cogito argument is to provide a sound foundation of knowledge, it fails in that purpose even when transposed into a valid argument. — Bunji

1. I think
2. If I think then there's a thinking thing
Ergo
3. There's a thinking thing

1 can't be denied. To deny 2 you'd need to have thinking without a thinking thing. Any ideas how to go about denying 2?

No. The ability to differentiate the two is an obvious indicator of their difference. If you have A=A say "but in this case A was a B" this leads to B=B. It is still the same. Even if I (obligingly) wrote A=B with "B not=A" this would only prove that such a thing cannot be, logically.

"A=B & B not = A" is a logical contradiction. It doesn't provide us with knowledge because it's nonsense. But if I say "Elephants are different from antelopes", that is either true or false as a matter of empirical enquiry, not of logical necessity. It provides us with knowledge because is true, but is not true of logical necessity (it is open to the logical possibility of doubt).

Any ideas how to go about denying 2?

Who's trying to deny it?

Any ideas how to go about denying 2? — TheMadFool

An assumption is made that everything would need a cause.

"A=B & B not = A" is a logical contradiction. It doesn't provide us with knowledge because it's nonsense. — Bunji

Exactly.

But if I say "Elephants are different from antelopes", that is either true or false as a matter of empirical enquiry, not of logical necessity. — Bunji

First of all, you have again shifted the subject of discussion from "an elephant" to elephants. This again is asking for essence. I do not need to /say/ what the difference between two objects is, it is enough for them to be distinguishable. To subsume particular objects under some concept of "type" is not necessarily a valid starting point. And yet this seems to be what you are always trying to do here.

But admitting that is not the same thing as admitting the possibility of doubt concerning the proposition that it actually does express. It is merely to allow the possibility that words used to express that proposition may have meant things other than they actually do. That is not doubt, that is just accepting alternative linguistic possibilities.

This simply begs the question of what proposition is actually being expressed. Knowing that x is an ant is not separable from knowing what "ant" means. The truth-conditions for the proposition "x is an ant" give the meaning of "ant", as Donald Davidson would say. To question whether or not x is an ant is to question what "ant" means. Suppose I say "The evening star is not the morning star." We know very well that this proposition is false, because as it happens "the evening star" refers to Venus, and so does "the morning star". But it might have been otherwise. The logical possibility of doubt exists there (i.e. of doubt that the proposition is false in this case). If I say "kestrels are not windhovers", how would you go about finding out if that is true or false? You may know already, or you may know what a kestrel is but not what a windhover is. If you didn't know what a windhover is, you'd need to look up the word "windhover", and then you'd find out that "windhover" is an alternative name for "kestrel". So then you'd know that "kestrels are not windhovers" is false. But it might have been true, just as "Ants are not elephants" might have been false.

In any case, if you are attempting to lay down a necessary or sufficient or necessary and sufficient condition for what counts as knowable, you are not being very Wittgensteinian...

Admittedly KILPOD does sound like a (proposed) necessary condition for knowledge. But then you'd have to accuse Wittgenstein of not being very Wittgensteinian. Here's a quote from Andy Hamilton's Wittgenstein and On Certainty (Routledge 2014): "KILPOD is stated at OC 58: " 'There is no such thing as a doubt in this case'...it follows from this that 'I know' makes no sense either" (also OC 41, 121-23). And OC 10 rejects the Cartesian view: "One thinks that the words 'I know that...' are always in place when there is no doubt, and hence where the expression of doubt would be unintelligible" - that is, where there is no logical possibility of doubt. His implication is that they are not in place in such a situation."

In other words, if "Ants are not elephants" were beyond the logical possibility of doubt, then "Ants are not elephants" would not count as knowledge. But because it's an empirical proposition, it is open to the logical possibility of doubt, so it does count as knowledge.

First of all, you have again shifted the subject of discussion from "an elephant" to elephants. This again is asking for essence. I do not need to /say/ what the difference between two objects is, it is enough for them to be distinguishable. To subsume particular objects under some concept of "type" is not necessarily a valid starting point. And yet this seems to be what you are always trying to do here.

First of all, the subject of discussion to which you refer was between myself and jkg20. Only you are insisting that I keep shifting the subject from "an elephant" to "elephants", even though jkg20 has also gone from "no ant is an elephant" to "ants are not elephants". That's because jkg20, unlike you, understands that the two propositions are logically equivalent. You can't say "no ant is an elephant" without subsuming particular objects under the type-concepts of "ant" and "elephant". "No ant is an elephant" means not a single object of the type "ant" is an object of the type "elephant". This of course is a true proposition. But we have to understand what ants in general are and what elephants in general are in order to know that it is true.

Secondly, to talk about "elephants" (as opposed to "an elephant") is not "asking for essence". To assume that concepts of type involve "essences" is a specifically Platonic assumption, against which Wittgenstein is well known for arguing in his later philosophy. You may have noticed my frequent references to Wittgenstein in my discussions with jkg20 (the purpose of which is to establish an anti-Cartesian position. Descartes was an essentialist.

Only you are insisting that I keep shifting the subject from "an elephant" to "elephants", even though jkg20 has also gone from "no ant is an elephant" to "ants are not elephants". — Bunji

If I point to a thing and label it an elephant I do not need to know what an elephant is besides the one thing I pointed to. So the proposition system you cite is not the criteria to call things elephants in the first place. So with Descartes. If we call the environment we live in "world" this is the definition of "world". It cannot be something else as this would imply a definition would be different from the thing. But the thing was the definition to start with.
If we take the proposition system of "elephantness" (see the essence) and /ask/ if a given object is an elephant this must either be true or not. If this is true and the object /later/ turns into an ant this just means the elephant turned into an ant. Nothing more nothing less.

If I point to a thing and label it an elephant I do not need to know what an elephant is besides the one thing I pointed to.

In order to correctly label it an elephant, you need to know that the thing you point to is an elephant. So you at least need to know what an elephant looks like. Otherwise you're just talking about pointing to something, which could be anything, and labelling it an elephant. If you didn't know any facts about ants or elephants, you wouldn't know to label an elephant as an elephant rather than as an ant.

Is there a distinction between doubting the proposition that a sentence expresses, and doubting what proposition that sentence expresses? It seems to me that there is, but that it is a distinction that threatens to be collapsing under your defence of KILPOD.

To question whether or not x is an ant is to question what "ant" means.

Well, that depends on the reference of "x" doesn't it? I can imagine being uncertain whether a particular thing referred to by x in the expression "x is an ant" is indeed an ant or whether in fact a termite, for instance. That would be a case of questioning whether x is an ant or not, yet it is not, at least not clearly, a question about what "ant" means. It would be more natural to think that it was a question as to whether, given that the meaning of "ant" and "termite" are agreed, the x should be classed as one or the other. There might be cases where it really is not clear even to experts whether the x should be classed as an ant or a termite, and there one might think that it is actually the meaning of the terms that is being brought into question as well, but that is a very specific kind of case.

Who's trying to deny it? — Bunji

Then we have no disagreement. :up:

An assumption is made that everything would need a cause. — Heiko

I don't think this is Descartes' assumption. It looks like Descartes is supposing that thinking has a cause and that cause is the "thinking thing" but, in my humble opinion, this is an incorrect application of the axiom of causality. When we investigate the cause of a fire (the cause of thinking) we must first accept 1) there's a fire (thinking) and 2) something that's on fire (the thinking thing). We then try to find out what caused the something that's on fire (the thinking thing) to burn/catch fire (thinking). The something that's on fire (the thinking thing is part of the event (something is thinking) and can't be used as part of the causal explanation for the said event.