Hi Ken

very interesting, ....... (at the risk of digressing, we would inadvertently get into psychology..... even so, lets indulge) Beliefs are just one aspect of the mind's working. the relationship it has with the world is dubious.

I get a feeling, that you may have just articulated it well or further qualified what i said. Misrepresentation of facts or gaps in understanding in our mind is what is belief. (relationship or gap in here connotes the same). The moment the fact is revealed or learned or obseved or thought about (as true) than at that moment we see it as knowledge. True knowledge. Knowledge, of course can further be refined.

Now, about other minds........ My pleading to the O Poster, is simple. The existence of other mind cannot be disputed because he and I and you are presently conversing in an commonly known language called English in a world or tool or platform called internet.

The rest of the quest becomes academic, or a philosophers past time.

As I said, for a belief to be true, it has to correspond with some fact in the world. So, for instance, for the belief that the cat is on the mat to be true, the cat has to be on the mat. If there is a cat, but no mat, or a mat, but no cat, or a mat and a cat, but the cat is not on the mat, then the belief that the cat is on the mat is false. (As Aristotle pointed out, there are many ways to falsity, but only one way to truth). So, at least beliefs do have that truth (or falsity) relation to the world.

Of course, what we "see" as knowledge need not be knowledge at all. For us to know that some proposition is true, the proposition has to be true, and our belief that the proposition is true needs to be adequately justified. After all, even a true belief need not be knowledge, since a true belief might be just a lucky guess, and a lucky guess is not knowledge. So even if I believe that the cat is on the mat, and the cat is on the mat, that makes my belief true, but that need not mean that I know that the cat is on the mat.
Even if I think I know something, that doesn't meant that I do know that thing. I can be mistaken about whether I know just as I can be mistaken about my height, or about my weight. True knowledge is, of course, just knowledge. The true part is to indicate that it not only seems to be knowledge, but it is really, knowledge.

The existence of other minds not only can be disputed, it has been disputed. And if it has been, then it can be. What you mean, I think, is that it should not be disputed, because our justification for our belief is so strong that we can say that we know there are other minds. And that, of course, may well be true.

I don't know whether that is the real question, but Descartes held that the I was a mind or soul, and not a body. So he certainly did answer that question. In fact, Descartes presented an argument for the conclusion that the I was identical with the mind or the soul, but not the body. His argument was:

1. I can doubt I have a body.
2. But I cannot doubt I have a mind.
Therefore, 3. I am a mind (and not a body).

Truth is a relation between belief and the world. If my belief corresponds to how the world is, then my belief is true. If it does not, then my belief is false. Aristotle wrote: To say what is true is to say that what is, is, and to say that what is, is not. That seems right to me.

So, for it to be true that there are other minds is for my belief (or statement) that there are other minds to be so related to the world that it corresponds to how the world is.

That argument is formally deductively invalid, though it may nonetheless be deductively valid. Are you sure that is a good formulation of it? I read parts of Descartes's work and I seem to recall another argument concluding that "I am not my body". Perhaps you know it. I skimmed the text but didn't find it.

---------- Post added 10-29-2009 at 07:26 PM ----------



It's not beliefs that are true or false. It is propositions, that is, what is believed. Not being precise here adds confusion. Saying that it is beliefs that are true and false in themselves, sometimes make people think that when no one believes something, it is not true or false. That's very confused.

Well explained. I am with you mate.



Sorry,... i could not get anything of this......?

I cannot doubt that the postman is the person who delivers my mail.
I can doubt that the postman is a person who lives near me

Therefore, the person who delivers my mail is not a person who lives near me.

Obviously fallacious argument. And, of course has the same form as Descartes's argument. Therefore, Descartes's argument is fallacious.

Yes, Descartes also argues:

I can doubt I have a body
I cannot doubt I exist.

Therefore, I am not my body.

This is fallacious for the same reason as above.

This is deja lu all over again. I am using the term "belief" in the sense of what is believed, not the believing. And what is believed is identical with the proposition believed. So, yes we can call it the proposition believed.

Hmm.

What is the logical form of these arguments? It's a bit hard because of the ambiguity of "is". The "is" of predication and the "is" of identity.

Form of the first argumentTranslation from logic to english again
1. It is not the case that it is possible that I doubt that the postman is identical with the person who delivers my mail.

2. It is possible that I doubt that the person who delivers my mail lives near me.

Thus, 3. It is not the case that the person who delivers my mail lives near me.

Special language use
I am using a special way of expressing the propositions in english. I am working on a system using english but retaining the clarity of logic. The above should be pretty unambiguous and yet understandable by native english speakers. More on this in a future essay but some of the groundwork has been done in this essay (15 pages).

Form of the first argumentTranslation from logic to english again
1. It is not the case that it is possible that I doubt that I exist.

2. It is possible that I doubt that there exists a thing such that I have that thing and that thing is a body.

Thus, 3. I am not identical with my body.

Thoughts
These forms do not seem analogous. How did you conclude that they were? Of course my analysis may not show it and it is still the case, but what analysis did you use?

Notice the problem with the second argument. I had to interpret the doubted part as an indefinite object and thus not a particular. If it was the same particular that is used in the conclusion, then the sentence expressing (2) would read "It is possible that I doubt that I have my body." which seems unwanted to me.



Ok. I think you ought to be more precise when you write posts then. Obviously I can't force you. Using shorthands is useful, but mostly when the audience knows that you are indeed using shorthands. I suppose that many people reading your posts on this board do not know that you use "the belief is true" to mean "the proposition believed is true".

What does "deju lu" mean?

It is not "I think, therefore I am." but rather "I think, therefore you are."

For me Descartes 'I think therefore, I am' contains tacitly held premises (such as 'Everything that thinks is, or exists') something which Descartes strongly denied saying in that 'I think therefore I am' was not something that could be known through a syllogism but rather was something that we recognize as self evident but Descartes in my opinon fails to justify this.

Also Hobbes in his objections to Descartes Meditations made one very valid point in regards to the 'I' Descartes was trying to prove, that from 'I am thinking, I am thought' doesnt follow.

Hobbes was right about that. But that is a straw-man, since that was not Descartes's argument for his essence being thought. He had a different argument for that. It is true that Descartes denied that his argument was syllogistic, because it was objected that he was assuming that whatever thinks exists. (Actually, I think he should have admitted that, and held that was self-evident, since it is just a case of existential generalization which modern logic simply assumes). His shift to the defense that his existence is an "intuition" may have been his way of saying just that. That if there is a property, then something has it.

Formally:
(∃x)(Ti)⇒(∃x)(x=i)

Right you are! Only Plato did not think that was true.

For me Descartes 'I think therefore, I am' contains tacitly held premises (such as 'Everything that thinks is, or exists') something which Descartes strongly denied saying in that 'I think therefore I am' was not something that could be known through a syllogism but rather was something that we recognize as self evident but Descartes in my opinon fails to justify this.

Also Hobbes in his objections to Descartes Meditations made one very valid point in regards to the 'I' Descartes was trying to prove, that from 'I am thinking, I am thought' doesn't follow.

I've also been thinking of some alternative theories that involve the idea of "concept". To say that a duck exists in my room is equivalent to saying that the concept of a duck is exemplified in my room. To say that a duck does not exist in my room is equivalent to saying that the concept of a duck in not exemplified in my room.

In this way we also avoid putting predicates on non-existing things.

I don't feel sufficient proof has been given to validate the statement "i think, therefore i am" .