Evidence versus Proof

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kennethamy
 
Reply Tue 17 Nov, 2009 11:24 am
@Emil,
Emil;104071 wrote:
I think it's close to being a category error to say that a proposition is certain. The only thing I can imagine that to mean is that the proposition is necessarily true.



Yes. Descartes held that he was certain that he existed. But Descartes certainly did not think that the proposition that he existed was a necessary truth. He thought that the only existential proposition that was a necessary truth was that God exists. (Descartes did not think that he was God). It seem to me that to say that p is certain is just a loose way of saying that I am certain that p. A different question is whether I am certain of all necessary truths. It seems to me that the answer to that must be, no.
 
Emil
 
Reply Tue 17 Nov, 2009 12:10 pm
@kennethamy,
kennethamy;104089 wrote:
Yes. Descartes held that he was certain that he existed. But Descartes certainly did not think that the proposition that he existed was a necessary truth. He thought that the only existential proposition that was a necessary truth was that God exists. (Descartes did not think that he was God). It seem to me that to say that p is certain is just a loose way of saying that I am certain that p. A different question is whether I am certain of all necessary truths. It seems to me that the answer to that must be, no.


I agree.

As for being certain of all necessary truths, I agree. That implies that the correct analysis of epistemic certainty is not the first one that I mention in my essay.

---------- Post added 11-17-2009 at 07:12 PM ----------

fast;104088 wrote:
This post is just to note another difference between being infallibly certain and confidently certain.

1. Certain (infallible): I am certain means I am infallible.
2. Certain (confident): I am certain means I am confident.
3. Certain (particular): another discussion

Observation 1: In regards to number 1 above, Amy is either certain or she isn't. In other words, she's either infallible or she isn't. There's no in between--no degrees of certainty; hence, no degrees of fallibility.

Observation 2: In regards to number 2 above, Bob is confident, but not as confident as Amy, yet more confident than Charles. In other words, there are varying degrees of confidence; hence, there are varying degrees of certainty.

Conclusion:
1. Certain (infallible): no varying degrees of certainty or fallibility.
2. Certain (confidence): varying degrees of certainty and confidence.


Basically what I wrote in my essay. Except that about the word "certain" being used to mean particular. I should mention that too.
 
Zetherin
 
Reply Tue 17 Nov, 2009 12:26 pm
@fast,
Emil wrote:

That phrase is a case of misusing language.


Ya gotta fight fire with fire sometimes, man!

Quote:

Well. I did tell you to learn logic first, and then discuss things. You're doing it backwards.


That's right, I am doing it backwards. I'm planning on contemplating tough logic problems for another decade. Then, ten years down the line, I'm going to start formally learning logic. Ya know, actually open a logic textbook or something. In this way, I will stay thoroughly confused for as much time as possible (heck, I should really increase this to about 20-30 years) before understanding what all the formalizations mean. If all goes as planned, right before I die I'll have just understood things I was contemplating for the better part of my life.

This is the philosopher's way.

Sorry, I'll stop posting here - you guys write, I'll read! Very Happy
 
fast
 
Reply Tue 17 Nov, 2009 12:59 pm
@fast,
Here's some more thoughts on the matter:

I can be confident that p, but not only that, I can be confident. Of course, if I'm confident that p, then I'm confident (for being confident that p implies being confident), but that I'm confident doesn't imply that I'm confident that p. For example, I can be a somewhat confident person in general without being confident that p, so there is a distinction. In fact, I am a confident person, but not so confident that p-depending on what p is, of course.

The point of that was simply to illustrate a difference between being confident and being confident that p. Notice how the distinguishing point holds true for being certain; hence, when using "certain" to mean confident, I can either be certain or certain that p; thus, I can either be confident or confident that p. There are more combinations.

But, this doesn't strike me as correct when talking about fallibility. It just doesn't ring true to the ear. Yes, we are fallible, so yes, we are not certain, but because "fallible that p" doesn't make sense to me, neither does "certain that p" make sense when using "certain" to mean infallible. What in the Quito does "John is fallible that p" mean?

So (or to recap), in regards to being certain (confident), I can be certain and thus confident, and on top of that, I can be certain that p and thus be confident that p; however, in regards to being certain (infallible), I can be certain (at least in a world where God allows it) and thus I can be infallible, but to go that extra mile and say that I can be certain that p (or infallible that p) seems to be stretching things a bit too far.

Yet, I can't escape that Kennthamy has done just that when he said: "For John to be certain that p, is for it to be impossible that John is mistaken that p." The only explanation I have is that it need not ring true to the ear for it to be so.

I'm okay with saying "certain that p" when "certain" means confidence, but I'm not so fine with saying "certain that p" when "certain" means infallible. I'm okay with being certain meaning being infallible, but that "that p" part has got to go.
 
Emil
 
Reply Tue 17 Nov, 2009 03:42 pm
@Zetherin,
Zetherin;104097 wrote:
Ya gotta fight fire with fire sometimes, man!



That's right, I am doing it backwards. I'm planning on contemplating tough logic problems for another decade. Then, ten years down the line, I'm going to start formally learning logic. Ya know, actually open a logic textbook or something. In this way, I will stay thoroughly confused for as much time as possible (heck, I should really increase this to about 20-30 years) before understanding what all the formalizations mean. If all goes as planned, right before I die I'll have just understood things I was contemplating for the better part of my life.

This is the philosopher's way.

Sorry, I'll stop posting here - you guys write, I'll read! Very Happy


Very Happy

It's really not that hard to learn logic. Unless you are not a gifted person for symbols. Some people are afraid of symbols.

Maybe the continental philosophers' way...

---------- Post added 11-17-2009 at 10:44 PM ----------

fast;104109 wrote:
Here's some more thoughts on the matter:

I can be confident that p, but not only that, I can be confident. Of course, if I'm confident that p, then I'm confident (for being confident that p implies being confident), but that I'm confident doesn't imply that I'm confident that p. For example, I can be a somewhat confident person in general without being confident that p, so there is a distinction. In fact, I am a confident person, but not so confident that p-depending on what p is, of course.

The point of that was simply to illustrate a difference between being confident and being confident that p. Notice how the distinguishing point holds true for being certain; hence, when using "certain" to mean confident, I can either be certain or certain that p; thus, I can either be confident or confident that p. There are more combinations.

But, this doesn't strike me as correct when talking about fallibility. It just doesn't ring true to the ear. Yes, we are fallible, so yes, we are not certain, but because "fallible that p" doesn't make sense to me, neither does "certain that p" make sense when using "certain" to mean infallible. What in the Quito does "John is fallible that p" mean?

So (or to recap), in regards to being certain (confident), I can be certain and thus confident, and on top of that, I can be certain that p and thus be confident that p; however, in regards to being certain (infallible), I can be certain (at least in a world where God allows it) and thus I can be infallible, but to go that extra mile and say that I can be certain that p (or infallible that p) seems to be stretching things a bit too far.

Yet, I can't escape that Kennthamy has done just that when he said: "For John to be certain that p, is for it to be impossible that John is mistaken that p." The only explanation I have is that it need not ring true to the ear for it to be so.

I'm okay with saying "certain that p" when "certain" means confidence, but I'm not so fine with saying "certain that p" when "certain" means infallible. I'm okay with being certain meaning being infallible, but that "that p" part has got to go.


With "fallible", you need to use another preposition, "about". "Fallible about p".
 
fast
 
Reply Tue 17 Nov, 2009 04:06 pm
@fast,
No, I think "certain that p" translates fine into "certain that the proposition p is true." Maybe it's just redundant. Being infallible implies that I can't be mistaken regardless of p, so adding "that p" adds nothing that I didn't already know, yet I can hardly blame him for being explicit.

Such implication isn't there in regards to confidence, as it doesn't imply that because I'm confident that I am confident that p.

At any rate, it was just some thoughts.
 
Emil
 
Reply Tue 17 Nov, 2009 04:51 pm
@fast,
[QUOTE=fast;104141]No, I think "certain that p" translates fine into "certain that the proposition p is true." Maybe it's just redundant. Being infallible implies that I can't be mistaken regardless of p, so adding "that p" adds nothing that I didn't already know, yet I can hardly blame him for being explicit. Such implication isn't there in regards to confidence, as it doesn't imply that because I'm confident that I am confident that p.

At any rate, it was just some thoughts.[/QUOTE]


There is a difference between being infallible and being infallible about p. The difference is that the first means to be infallible about all p.

Besides you are wrong about confident too. Being confident that p does not imply being confident (in general). One can be confident about some proposition and not be confident in general.

This damn font and size changing... The default font and size seems to be Times New Roman size 3. Just manually pick that in all posts.
 
fast
 
Reply Wed 18 Nov, 2009 09:56 am
@Emil,
[QUOTE=Emil;104148]There is a difference between being infallible and being infallible about p. [/QUOTE]Yes, I agree.

[QUOTE]The difference is that the first means to be infallible about all p.[/QUOTE]Yes, and that implies that one is infallible about p.

Being confident, however, doesn't imply being confident that p.

[QUOTE]Besides you are wrong about confident too. Being confident that p does not imply being confident (in general). [/QUOTE]Uh. But, I agree with that!

[QUOTE]One can be confident about some proposition and not be confident in general.[/QUOTE]That's right, but being confident doesn't imply being confident about p whereas being infallible does imply being infallible that p.

So, they are not parallel.

[QUOTE]This damn font and size changing... The default font and size seems to be Times New Roman size 3. Just manually pick that in all posts.
[/QUOTE]I'm working on it. Sometimes, it won't let me scroll down to times new roman; either that, or it just takes too darn long (a cousin to too long). I'm on dial up, and that makes getting around on this forum horrific.
 
Emil
 
Reply Wed 18 Nov, 2009 10:10 am
@fast,
fast;104314 wrote:
Yes, I agree.


Good.

fast;104314 wrote:
Yes, and that implies that one is infallible about p.

Being confident, however, doesn't imply being confident that p.


Agreed.

fast;104314 wrote:
Uh. But, I agree with that!


Maybe. But you wrote, just before:[INDENT] "I can be confident that p, but not only that, I can be confident. Of course, if I'm confident that p, then I'm confident (for being confident that p implies being confident), but that I'm confident doesn't imply that I'm confident that p. For example, I can be a somewhat confident person in general without being confident that p, so there is a distinction. In fact, I am a confident person, but not so confident that p-depending on what p is, of course." (My emphasis)
[/INDENT]
fast;104314 wrote:
That's right, but being confident doesn't imply being confident about p whereas being infallible does imply being infallible that p.

So, they are not parallel.


Agreed.

fast;104314 wrote:
I'm working on it. Sometimes, it won't let me scroll down to times new roman; either that, or it just takes too darn long (a cousin to too long). I'm on dial up, and that makes getting around on this forum horrific.


I think I found a solution. Every time you are done writing. Mark all the text and press the reset formatting symbol in the editor. It works for me. Here's a screenshot:
http://img21.imageshack.us/img21/8074/shot00118nov091708.jpg

(Damn forum does not support images either! In this respect FRDB was much, much better. Images, hide tags, tables.. In short we had the best SysAdmin!)

ETA. It does remove your other formatting too though (e.g. bold text), so you have to remember to do that afterwards.
 
fast
 
Reply Wed 18 Nov, 2009 10:33 am
@Emil,
[INDENT]Of course, if I'm confident that p, then I'm confident (for being confident that p implies being confident), but that I'm confident doesn't imply that I'm confident that p.
[/INDENT]
Being confident that p implies that I'm confident in so much that I am confident that p.

I should never have brought up being confident in gereral. It was misleading, but my only reason for including it was to further illustrate that there's a difference, but it's a moot point since we agree.

Here's something more interesting:

1: being certain (confident)
2: being certain (confident) that p.
3: being certain (infallible)
4: being certain (infallible) that p.

3 implies 4 but 1 doesn't imply 2. Being infallible implies that I am infallible in regards to all p, but being confident doesn't imply that I am confident about all p. So, 2 can imply 1 whereas 4 can't imply 3.

Hope that helps.
 
Emil
 
Reply Wed 18 Nov, 2009 10:44 am
@fast,
fast;104326 wrote:
[INDENT]Of course, if I'm confident that p, then I'm confident (for being confident that p implies being confident), but that I'm confident doesn't imply that I'm confident that p.
[/INDENT]Being confident that p implies that I'm confident in so much that I am confident that p.

I should never have brought up being confident in gereral. It was misleading, but my only reason for including it was to further illustrate that there's a difference, but it's a moot point since we agree.

Here's something more interesting:

1: being certain (confident)
2: being certain (confident) that p.
3: being certain (infallible)
4: being certain (infallible) that p.

3 implies 4 but 1 doesn't imply 2. Being infallible implies that I am infallible in regards to all p, but being confident doesn't imply that I am confident about all p. So, 2 can imply 1 whereas 4 can't imply 3.

Hope that helps.


I agree with everything except this:
[INDENT]"So, 2 can imply 1 whereas 4 can't imply 3."
[/INDENT]This is too vague, and it doesn't seem to follow from anything else you wrote. I will clarify what I think:

  • 2 does not logically imply 1.
  • It is possible that 2 materially implies 1.
  • 2 does not materially imply 1.
  • 4 does not logically imply 3.
  • It is possible that 4 materially implies 3.
  • 4 does not materially imply 3. (Maybe)
 
Egosum
 
Reply Thu 19 Nov, 2009 09:38 pm
@fast,
I have proof that god exists. I can show you logically that god exists.

I have evidence that god exists. I can show you physically that god exists.

I find it best to just categorize them both that way. I thought they were interchangeable at first, but it seems the concept of proof is logic while the concept of evidence is physical.
 
kennethamy
 
Reply Thu 19 Nov, 2009 11:39 pm
@Egosum,
Egosum;104587 wrote:
I have proof that god exists. I can show you logically that god exists.

I have evidence that god exists. I can show you physically that god exists.

I find it best to just categorize them both that way. I thought they were interchangeable at first, but it seems the concept of proof is logic while the concept of evidence is physical.


People often use evidence to prove, for instance, that X murdered Y in a court of law. "Physical evidence" (like fingerprints, or blood samples) is sometimes contrasted with testimony by an eye-witness, but both are considered evidence. But eye-witness testimony is not considered physical evidence.
 
Reconstructo
 
Reply Thu 26 Nov, 2009 12:09 am
@kennethamy,
I think there's only Persuasion. The word proof is useful, of course. But what does it really mean to prove something, beyond a strong use of the word persuasion?

What about antecedent skepticism? Isn't all of our knowledge founded upon a leap of faith in our sanity, and in our general ability to ascertain "truth?"

Is Certainty another idol, another plug for the god-shaped hole? And I refer to certainty with a capital C.
 
Emil
 
Reply Thu 26 Nov, 2009 02:03 am
@Reconstructo,
Reconstructo;106028 wrote:
I think there's only Persuasion. The word proof is useful, of course. But what does it really mean to prove something, beyond a strong use of the word persuasion?

What about antecedent skepticism? Isn't all of our knowledge founded upon a leap of faith in our sanity, and in our general ability to ascertain "truth?"

Is Certainty another idol, another plug for the god-shaped hole? And I refer to certainty with a capital C.


And why do you refer to capital C certainty? People have some peculiar tendency to capitalize words e.g. "Truth".
 
kennethamy
 
Reply Thu 26 Nov, 2009 05:53 am
@Reconstructo,
Reconstructo;106028 wrote:
I think there's only Persuasion. The word proof is useful, of course. But what does it really mean to prove something, beyond a strong use of the word persuasion?

What about antecedent skepticism? Isn't all of our knowledge founded upon a leap of faith in our sanity, and in our general ability to ascertain "truth?"

Is Certainty another idol, another plug for the god-shaped hole? And I refer to certainty with a capital C.


You seem to be confusing "proving" with "proving to" somebody. A sound argument constitutes a proof whether or not anyone is persuaded by it. It is very like truth. It was true that the Earth was round whether or not anyone was persuaded that it was. There are still "flat-earthers" who are not persuaded by the evidence. So what?
 
Reconstructo
 
Reply Fri 27 Nov, 2009 01:44 am
@kennethamy,
There is only a consensus that the Earth is round. You think so. I think so. Most people think so. It's only proven to the point that we are persuaded.

Perhaps we are brains in a vat. In the practical sense this is ridiculous, but I am trying to make a point. If you were the only person who thought the Earth was round, you would be repeatedly told that you were insane, and you would start to doubt yourself.
This is an exaggerated sort of example, but it will serve well enough.

I refer to capitalization in order to call attention to what I would call religious feelings for certain concepts. As I said in another post, the philosophical tradition is full of round-about theologians, and I am being metaphorical. Plato, Spinoza, Hegel, Kant. Just to name a few. And before someone says Kant is anti-metaphysics, let's consider the categorical imperative. Kant was sneaky. He wanted to play scientist and saint simultaneously. Russell and Wittgenstein liked the uniforms that referees wear.

Smile
 
Reconstructo
 
Reply Tue 1 Dec, 2009 05:35 pm
@fast,
What qualitative difference is there between "proof" and "persuasion." Something is proven to a person when they have been persuaded of it. We call what is persuasive "logical."
I agree that total certainty is about as significant as the Easter Bunny. We act in this risky world with less than total certainty. We believe other humans that may or may not be lying. We consider abstract metaphorical propositions as something we may want to assimilate. Where is this "logic" that transcends "rhetoric"? Or is "logic" (non-formal) just rhetoric we approve of?

And does formal logic serve at times as a shiny toy that appeals to us by means of a clarity that real life lacks?
 
kennethamy
 
Reply Tue 1 Dec, 2009 06:39 pm
@Reconstructo,
Reconstructo;106307 wrote:
There is only a consensus that the Earth is round. You think so. I think so. Most people think so. It's only proven to the point that we are persuaded.

Perhaps we are brains in a vat. In the practical sense this is ridiculous, but I am trying to make a point. If you were the only person who thought the Earth was round, you would be repeatedly told that you were insane, and you would start to doubt yourself.
This is an exaggerated sort of example, but it will serve well enough.

I refer to capitalization in order to call attention to what I would call religious feelings for certain concepts. As I said in another post, the philosophical tradition is full of round-about theologians, and I am being metaphorical. Plato, Spinoza, Hegel, Kant. Just to name a few. And before someone says Kant is anti-metaphysics, let's consider the categorical imperative. Kant was sneaky. He wanted to play scientist and saint simultaneously. Russell and Wittgenstein liked the uniforms that referees wear.

Smile


Even if people were not persuaded as in the Middle Ages, the Earth was still round, and it had been proven to be so. If only I believed the Earth was round what I believed would be true. But, of course, a lot would depend on why I held that belief. That I would be told I was insane, or called insane would not mean I was insane. That I might believe it myself does not show I would be insane. Why should it?
 
Reconstructo
 
Reply Tue 1 Dec, 2009 07:18 pm
@kennethamy,
How do you know the Earth is round? You have been persuaded that it is round. And so have I. Have you been in orbit? And even if you had, could one not doubt one's sense-impressions? Is a stick not crooked in water?

And perhaps you are indeed a brain in a vat..... Can you prove that you are not? Or will you, lawyer-like, make a case against this unpleasant possibility.

The point is our lack of direct connection to things-in-themselves. -- and also that "things-in-themselves" is just a mental-model, an invented concept.

You have an idea of the Earth in your head. This idea was put there. Another person might be told the Earth is flat. Perhaps your notion of the world is better for the prediction of certain events. Perhaps your notion is a superior notion as far survival goes. But your notion is not a final notion.

The case is not closed. It's just a cold case. You are persuaded enough of the Earth's roundness to cease investigation of the matter. And I, too, am in that boat. But I don't pretend to anything beyond provisional knowledge concerning the shape of Earth.
 
 

 
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