Not all cases have a referent "truth". That is, "actuality" is contextual; this is the central point I believe we should keep in mind.

An example where referent truth is present:
The capital legislation is exactly what I was referring to in my above post when I mentioned fixed logical systems that define "truth". In the legislation case, we have a record kept that is defined as "truth". Any schmuck with a 2 dollar city map can claim the capital of Ecuador is "Jinglefuck", but he would be wrong as the recorded "truth" of "Quito" is intersubjectively agreed upon. Intersubjective agreement is imperative in this case.

An example where referent truth is not present:
If my wife removed the vase 178 times during her cleaning process, she, in all practicality, wouldn't have kept a record. At work, despite this, I would say I know the vase is on the table. This means that even if my boss asked me at 3:34 if the vase was on the table, and I said "Yes, I know the vase is on the table", without knowing the vase wasn't going to be replaced on the table until 3:35, I would still be content with saying "I know...". This is because for all practical purposes the "know" in this context is a form of probability. The "truth" here is dynamic by it's very nature.

An example where referent truth is present, but "knowledge" is questionable:
A great majority of things we regard as scientific knowledge. The example I gave with Mars may sound farfetched, but I'm confident instances like these have occurred in the past. Particularly, as I noted, the "squaring the circle" problem. But, just to throw the example out there again: If scientists, through our current methods, deem Mars to be made of rock, can we not say this is scientific knowledge? Surely it would have to be intersubjectively agreed upon by scientists. Science is a method, so we do, by definition, have something to reference "truth" by - to a probability. If we regard Mars being made of rock as scientific knowledge, and then the human species discovers Mars is made of playdo 500 years from now, what then? Here we have "knowledge" being questioned and a referent truth present; we have what we at least think to be actuality.

So, when we just say, "Knowledge is JTB (Justified True Belief)", what are we actually saying? Is "truth" being considered from differing contexts?



ABC, please read above as this will also help our conversation.

To answer you, though: The case you brought up would be decided on intersubjective agreement. "Truth", in this case, does have a reference (see my last example), and those who work with the method (whatever science-related field) would come to a conclusion. The conclusion with the most authority we would deem scientific "knowledge".

That person, though, through his own methods (likely to be scientific in nature) has the potential to prove the earth is 6,000 years old. It's possible(not likely) that he could undermine all the research we've done on the aging of this planet and present a new case. If that case became popularized enough, we could deem that "knowledge". Hasn't this how things have always worked?

Besides the innerworkings of one's mind, if one mutters "knowledge", there is justification needed. So, belief, of course, isn't the only necessity. But, keeping in mind, that truth is muddy without clarification.

Or do you want to say that if I am in checkmate it is not possible for me not to be in checkmate?

it is possible in two ways that I am in checkmate, but that I am not in checkmate. Don't you agree?

Of course, I am not saying that it is possible that p and ~p are consistent. But I am saying that p, and it possible ~p, are consistent.

There is all the difference in the world between, possible p and ~p, and p and possible ~p. In the first, the scope of "possible" ranges over the entire sentence; in the second, the scope of "possible" ranges over only ~p. Thus the first is false, the second is true. Thinking that the first and the second are the same is to commit a modal fallacy. It is to switch the scope of the possibility operator without any reason.

If you merely believe or (some would say) know you are in checkmate, then it is possible that you are not. As you point out, 'I am in checkmate' is not a necessary truth. But if you are in checkmate, it is impossible for you not to be. That is a necessary truth, by the law of non-contradiction. It is logically impossible for something to be the case and not the case at the same time. In actual situations there is always some theoretical doubt, but you must be consistent about this; you can't ignore the doubt in one half of a statement ("I am in checkmate", period) and then assert it in the other half ("it is possible for me not to be in checkmate"). Do you see my point?



No; that is a simple logical contradiction, and thus necessarily false.



I take "p and possible ~p" to mean that p does apply and ~p may apply. It thus allows for two possibilities: (a) p only, and (b) p and ~p. But (b) is a contradiction.

I don't see why you say that both these propositions define "knowledge" as something I don't know. I have already said that ir I know that p is true, then p is true. I cannot know that p is true unless p is true. I think you would have to say why you say this.

Why cannot I be right, and therefore know, even if I realize that it is not impossible that I am wrong? So I can know I am right without being certain that I am right.

I have already agreed that it is logically impossible for p and ~p to be true, but if you like I will say it again, take it as said. But that should not be confused with a different statement, namely, it is possible that p, and possible that ~p. For that is obviously true. All that means is that p is true, and that p is a contingent statement and not necessarily true. Thus, it is possible that Quito is the capital and it is possible that Quito is not the capital even if, of course, it is true that Quito is the capital. There is a use of, it is possible that ~p that means, for all I know, ~p. But I am not using it that way. I am using possible ~p simply to mean (for one thing) that ~p is not self-contradictory. And isn't it true that Quito is the capital of Ecuador, and that it is not self-contradictory the Quito is not the capital of Ecuador. It is false that it is not, but it is certainly not self-contradictory, is it?

Thanks for your clarification. I now understand that you are not making a logical contradiction. However, I think you are mixing up logical and factual statements.

Logical: It is possible (i.e.non-contradictory) that Quito is the capital of Ecuador, and possible that it is not. Possible p and possible ~p.

Factual: It is highly probable that Quito is the capital of Ecuador, and highly improbable that it is not. Probable p and improbable ~p.

Or alternatively:

Factual: It is (beyond reasonable doubt) true that Quito is the capital of Ecuador, and false that it is not. p and ~(~p).

You cannot consistently derive "p and possible ~p", because that confuses two different things. The "p" describes what is the case (fact), while the "possible ~p" describes what logically could have been the case (as I now understand you to mean). But if we are going to ignore any theoretical doubt when talking about p, we must equally ignore it when talking about ~p. So if we state categorically that p, we must conclude that ~p is (now) impossible. As I said, we must be consistent. (Note that when we are talking about fact rather than logic, "possible" can only mean "maybe true for all I know".)

What we observe all around us is really only a fraction of the reality. We are hard wired if you like to perceive only what we need to, in order to survive. A frogs eye only sends messages to its brain if it sees movement.

We perceive more, take the electromagnetic spectrum, our visual cortex and eye observes just a tiny slit

Thanks for your clarification. I now understand that you are not making a logical contradiction. However, I think you are mixing up logical and factual statements.

Logical: It is possible (i.e.non-contradictory) that Quito is the capital of Ecuador, and possible that it is not. Possible p and possible ~p.

Factual: It is highly probable that Quito is the capital of Ecuador, and highly improbable that it is not. Probable p and improbable ~p.

Or alternatively:

Factual: It is (beyond reasonable doubt) true that Quito is the capital of Ecuador, and false that it is not. p and ~(~p).

You cannot consistently derive "p and possible ~p", because that confuses two different things. The "p" describes what is the case (fact), while the "possible ~p" describes what logically could have been the case (as I now understand you to mean). But if we are going to ignore any theoretical doubt when talking about p, we must equally ignore it when talking about ~p. So if we state categorically that p, we must conclude that ~p is (now) impossible. As I said, we must be consistent. (Note that when we are talking about fact rather than logic, "possible" can only mean "maybe true for all I know".)

Know doesn't mean "high probability". "High probability" means, high probability. "Know" means, it is true.

But why can I not know that p, and it be possible that I am mistaken? No reason that I can see.

Since you cannot know what is false, if the vase is not on the table, you cannot know is on the table. It does not matter whether someone takes what you say as implying that it is highly probable the vase is on the table. It does not matter how anyone takes what you say, for when you say that you know that something is true, but it is false, you have said what is false. Know doesn't mean "high probability". "High probability" means, high probability. "Know" means, it is true.

I don't think it is "muddy" when it is true that the cat is on the mat. It is true that there is a cat on the mat if, and only if, there is a cat, there is a mat, and the cat has a particular relation to the mat, namely the relation of being on the map. That is pretty clear, it seems to me.

If 'knowing that p' isn't probabilistic, then there shouldn't be a possibility of being mistaken - even if p is a contingent proposition. To say:

I know that p

and

Both p and possible ~p

is to conflate the indicative of 'knowing that...' with the counterfactual of the contingent proposition p.

If "know" means it is in fact true, it cannot turn out later to be false. If to know something is to believe something to be true that is in fact true, then to possess knowledge is to possess the truth. The indicative of p - not how p might have been.

Kennethamy - I seem to have been misled by your use of tenses. I think you mean that what you know to be true might now have been false if events had been different. It is true that Quito is the capital of Ecuador, but it was (not is) possible for it to be false. If that is what you mean, then of course I would agree, since we are talking about contingent truths.

If it was false, then how was it ever a "truth" at all? Are we saying that this *thing* cannot be false now, but can be false later?

Having knowledge bound by this "It must be true!" thing, I don't really get (as articulated in my last post).

"Truth" seems to be a metaphor for our desire to know, in many cases.

As life goes on, and we make mistakes and realize that most things are probabilities (I believe all things), then we replace T and F with, phrases like "I'm pretty sure", or "I think so", or "I am not sure", or even "I am positive", but we all learn that even the "I am positive", can end up being wrong.

If it was false, then how was it ever a "truth" at all? Are we saying that this *thing* cannot be false now, but can be false later?

Someone bound by logic will tell me, "A cannot be in X location and Y location at the same time!"

I didn't say it was false - I said it was possible (in the past) for it to be (now) false. In other words, in the past the matter had not yet been decided, but now it has.

"If A is in X location, then it is not the case that A is not in X location".

richrf,



Practically, most "truths" are probability. You can set up all the formal logic truth tables you want and I'll show you countless incidents where you can't "know" the "truth".