Evidence versus Proof

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fast
 
Reply Wed 11 Nov, 2009 02:22 pm

The police can have evidence that I have committed a crime even if I have not committed a crime-and even if no crime has been committed.

But, if I have not committed a crime, then the police cannot prove that I have committed a crime, even if they can prove beyond a reasonable doubt that I have.

Any objections?

Also, what is evidence, what is proof, and what's the difference?
 
Zetherin
 
Reply Wed 11 Nov, 2009 02:27 pm
@fast,
fast wrote:
But, if I have not committed a crime, then the police cannot prove that I have committed a crime, even if they can prove beyond a reasonable doubt that I have.
What is the difference between proving and proving beyond a reasonable doubt?
 
hue-man
 
Reply Wed 11 Nov, 2009 02:41 pm
@Zetherin,
I would say that in law evidence is an empirical circumstance that logically implies that the defendant committed the crime. Proof is when the evidence implies that it is logically impossible for the defendant to not have committed the crime. I suppose proof is rare in the court of law.
 
fast
 
Reply Wed 11 Nov, 2009 02:53 pm
@Zetherin,
Zetherin;103018 wrote:
What is the difference between proving and proving beyond a reasonable doubt?


First, let me say that I'm a bit more comfortable with my first statement than I am with this one, but I'll let you know what I had in mind when I said it. It may be a wording issue that I'm having.

I have it in my head that if I have proven something, then I have proven that some proposition is true, so if what is trying to be proven isn't true, then it cannot be proven true.

When we prove something beyond a reasonable doubt, this is a case when we are proving something to someone, so we're not really proving that it's true but rather proving it beyond a reasonable doubt that it may be true. Innocent people have been convicted of crimes despite the fact some juries have had no apparent good reason to doubt the defendants guilt.

---------- Post added 11-11-2009 at 04:01 PM ----------

hue-man;103023 wrote:
I would say that in law evidence is an empirical circumstance that logically implies that the defendant committed the crime.
I would not have thought that.

I think evidence is used to establish that some proposition is true, but that it may fail to do so doesn't imply that it's not evidence.

Quote:
Proof is when the evidence implies that it is logically impossible for the defendant to not have committed the crime. I suppose proof is rare in the court of law.


I think showing my identification serves as evidence that I am who I say I am, and if I'm who I say I am, then I have provided proof that I am who I say I am by providing the evidence I did.

However, if I give a false identification, then although I still think it's evidence to show who I am, I think it fails to prove that I am who I say I am.
 
Zetherin
 
Reply Wed 11 Nov, 2009 03:08 pm
@fast,
fast wrote:

I have it in my head that if I have proven something, then I have proven that some proposition is true, so if what is trying to be proven isn't true, then it cannot be proven true.

When we prove something beyond a reasonable doubt, this is a case when we are proving something to someone, so we're not really proving that it's true but rather proving it beyond a reasonable doubt that it may be true. Innocent people have been convicted of crimes despite the fact some juries have had no apparent good reason to doubt the defendants guilt.


Most things cannot be proven with the certainty that a deductive, or tautologically example, would allow us. For instance, I could prove 1+1=2 with mathematical and deductive proofs; in the end, it's true by definition, as it's a tautology. But, as you're probably aware, issues dealing with the temporal (such as, s/he did X at Y time) aren't as simple. We don't have "direct access" to some knowledge, so to say.

In the case of most legal matters, proving beyond a reasonable doubt is all we have. And evidence functions to support a case, to support this proof beyond a reasonable doubt. Whether what is purported in the case is true or not is irrelevant; it's simply what one can prove beyond a reasonable doubt. A convincing, not necessarily sound, argument is key.
 
fast
 
Reply Wed 11 Nov, 2009 03:35 pm
@Zetherin,
[QUOTE=Zetherin;103031]Most things cannot be proven with the certainty that a deductive, or tautologically example, would allow us.[/quote]

I think that I can prove that I am who I say I am without you being certain that I am who I say I am. For example, I can show you my identification as evidence that I am who I say I am, and if I'm who I say I am, then I do believe I have proven that I am who I say I am even though you will not be certain beyond all doubt reason that I am who I say I am. If that is inadequate justification for you to believe me, then I could get my mommy to testify on my behalf that I am who I say I am. Even then, you may not be so certain that it's impossible for you to be mistaken, but you'll still nevertheless know that I am who I say I am.
 
Zetherin
 
Reply Wed 11 Nov, 2009 05:04 pm
@fast,
fast;103040 wrote:


I think that I can prove that I am who I say I am without you being certain that I am who I say I am. For example, I can show you my identification as evidence that I am who I say I am, and if I'm who I say I am, then I do believe I have proven that I am who I say I am even though you will not be certain beyond all doubt reason that I am who I say I am. If that is inadequate justification for you to believe me, then I could get my mommy to testify on my behalf that I am who I say I am. Even then, you may not be so certain that it's impossible for you to be mistaken, but you'll still nevertheless know that I am who I say I am.


I completely agree with this. In this case, I would have no reason to believe otherwise; you would have proven beyond a reasonable doubt. But this doesn't mean that I would as certain that you are who you say you are as I would be that 1+1=2. And this is what I meant by the statement you quoted.
 
Emil
 
Reply Thu 12 Nov, 2009 01:59 am
@fast,
fast;103017 wrote:

The police can have evidence that I have committed a crime even if I have not committed a crime-and even if no crime has been committed.

But, if I have not committed a crime, then the police cannot prove that I have committed a crime, even if they can prove beyond a reasonable doubt that I have.

Any objections?

Also, what is evidence, what is proof, and what's the difference?


The dictionary is always the best place to start when discussing words. Multiple dictionaries help. I prefer to use Wiktionary to begin with.

Evidence

  1. Facts or observations presented in support of an assertion.
  2. (law) Anything admitted by a court to prove or disprove alleged matters of fact in a trial.

Proof

  1. Any effort, process, or operation designed to establish or discover a fact or truth; an act of testing; a test; a trial.


  2. The degree of evidence which convinces the mind of any truth or fact, and produces belief; a test by facts or arguments which induce, or tend to induce, certainty of the judgment; conclusive evidence; demonstration.


  3. The quality or state of having been proved or tried; firmness or hardness which resists impression, or doesn't yield to force; impenetrability of physical bodies.
  4. Firmness of mind; stability not to be shaken.
  5. (printing) A proof sheet; a trial impression, as from type, taken for correction or examination.
  6. (mathematics): A process for testing the accuracy of an operation performed. Compare prove, transitive verb, 5.
  7. (obsolete): Armour of excellent or tried quality, and deemed impenetrable; properly, armour of proof.
  8. (US) A measure of the alcohol content of liquor. Originally, in Britain, 100 proof was defined as 57.1% by volume (not used anymore). In the US, 100 proof means that the alcohol content is 50% of the total volume of the liquid, and thus, absolute alcohol would be 200 proof.

-

In the context of philosophy, the only difference I think there is between proof and evidence is that of strength. It's a matter of degree. Proof is stronger than evidence. This is pretty much in line with parts of #2 "conclusive evidence; demonstration". Other parts of #2 are subjective based on the idea of proving something to someone. (Cf. distinction between proving and proving to (aka. convincing).)

But proof need not be final as in increasing the probability of p to 1. Otherwise there would be no proofs; because; for all p, no thing increases the probability of p to 1.

---------- Post added 11-12-2009 at 09:04 AM ----------

Zetherin;103018 wrote:
What is the difference between proving and proving beyond a reasonable doubt?


The first is a general term and the second is used mostly in courts. I think proving is stronger than proving beyond a reasonable doubt. In other words: It is harder to prove something than to prove something beyond a reasonable doubt.

"A reasonable doubt" would mean here something like alternative theories that are probabilities and not mere (logical) possibilities. For instance, if a man is accused of murder but there he defense has another theory that is not ruled out by the evidence presented in court, the accused is not proven guilty beyond a reasonable doubt even though the prosecutor's theory may be more probable than the defendant's.

There is a weaker term than proven beyond a reasonable doubt; that of being more probable than it's negation.

---------- Post added 11-12-2009 at 09:05 AM ----------

hue-man;103023 wrote:
I would say that in law evidence is an empirical circumstance that logically implies that the defendant committed the crime. Proof is when the evidence implies that it is logically impossible for the defendant to not have committed the crime. I suppose proof is rare in the court of law.


I claim there is no final proof (cf. my earlier posts for that term, that is, "final proof"). Can you give an example of a final proof?

---------- Post added 11-12-2009 at 09:18 AM ----------

fast;103026 wrote:
First, let me say that I'm a bit more comfortable with my first statement than I am with this one, but I'll let you know what I had in mind when I said it. It may be a wording issue that I'm having.

I have it in my head that if I have proven something, then I have proven that some proposition is true, so if what is trying to be proven isn't true, then it cannot be proven true.
often

---------- Post added 11-12-2009 at 09:21 AM ----------

Zetherin;103031 wrote:
Most things cannot be proven with the certainty that a deductive, or tautologically example, would allow us. For instance, I could prove 1+1=2 with mathematical and deductive proofs; in the end, it's true by definition, as it's a tautology. But, as you're probably aware, issues dealing with the temporal (such as, s/he did X at Y time) aren't as simple. We don't have "direct access" to some knowledge, so to say.

In the case of most legal matters, proving beyond a reasonable doubt is all we have. And evidence functions to support a case, to support this proof beyond a reasonable doubt. Whether what is purported in the case is true or not is irrelevant; it's simply what one can prove beyond a reasonable doubt. A convincing, not necessarily sound, argument is key.


Even tautologies (i.e. necessary truths) are not matters of epistemic certainty. Just try doing advanced math and you will see how fallible you are.

Often is legal cases the arguments may be sound (true premises and valid) but their conclusions are not certain, just not because of the argument structure/inference type, but because the conclusion itself may be something like "The defendant probably did action a.".

And then there may be inductive arguments for the conclusion too and these are of course not sound (since they are invalid or perhaps non-valid if you don't think validity applies to inductive arguments).
 
kennethamy
 
Reply Thu 12 Nov, 2009 03:08 am
@Emil,
Emil;103091 wrote:
The dictionary is always the best place to start when discussing words. Multiple dictionaries help. I prefer to use Wiktionary to begin with.

Evidence

  1. Facts or observations presented in support of an assertion.
  2. (law) Anything admitted by a court to prove or disprove alleged matters of fact in a trial.

Proof

  1. Any effort, process, or operation designed to establish or discover a fact or truth; an act of testing; a test; a trial.


  2. The degree of evidence which convinces the mind of any truth or fact, and produces belief; a test by facts or arguments which induce, or tend to induce, certainty of the judgment; conclusive evidence; demonstration.


  3. The quality or state of having been proved or tried; firmness or hardness which resists impression, or doesn't yield to force; impenetrability of physical bodies.
  4. Firmness of mind; stability not to be shaken.
  5. (printing) A proof sheet; a trial impression, as from type, taken for correction or examination.
  6. (mathematics): A process for testing the accuracy of an operation performed. Compare prove, transitive verb, 5.
  7. (obsolete): Armour of excellent or tried quality, and deemed impenetrable; properly, armour of proof.
  8. (US) A measure of the alcohol content of liquor. Originally, in Britain, 100 proof was defined as 57.1% by volume (not used anymore). In the US, 100 proof means that the alcohol content is 50% of the total volume of the liquid, and thus, absolute alcohol would be 200 proof.

-

In the context of philosophy, the only difference I think there is between proof and evidence is that of strength. It's a matter of degree. Proof is stronger than evidence. This is pretty much in line with parts of #2 "conclusive evidence; demonstration". Other parts of #2 are subjective based on the idea of proving something to someone. (Cf. distinction between proving and proving to (aka. convincing).)

But proof need not be final as in increasing the probability of p to 1. Otherwise there would be no proofs; because; for all p, no thing increases the probability of p to 1.

---------- Post added 11-12-2009 at 09:04 AM ----------



The first is a general term and the second is used mostly in courts. I think proving is stronger than proving beyond a reasonable doubt. In other words: It is harder to prove something than to prove something beyond a reasonable doubt.

"A reasonable doubt" would mean here something like alternative theories that are probabilities and not mere (logical) possibilities. For instance, if a man is accused of murder but there he defense has another theory that is not ruled out by the evidence presented in court, the accused is not proven guilty beyond a reasonable doubt even though the prosecutor's theory may be more probable than the defendant's.

There is a weaker term than proven beyond a reasonable doubt; that of being more probable than it's negation.

---------- Post added 11-12-2009 at 09:05 AM ----------



I claim there is no final proof (cf. my earlier posts for that term, that is, "final proof"). Can you give an example of a final proof?

---------- Post added 11-12-2009 at 09:18 AM ----------

often

---------- Post added 11-12-2009 at 09:21 AM ----------



Even tautologies (i.e. necessary truths) are not matters of epistemic certainty. Just try doing advanced math and you will see how fallible you are.

Often is legal cases the arguments may be sound (true premises and valid) but their conclusions are not certain, just not because of the argument structure/inference type, but because the conclusion itself may be something like "The defendant probably did action a.".

And then there may be inductive arguments for the conclusion too and these are of course not sound (since they are invalid or perhaps non-valid if you don't think validity applies to inductive arguments).



In American courts, the burden of proof depends on the kind of case being decided. In the instance of criminal cases, when the penalties concern the freedom or even the life of the accused, the standard of meeting the burden of proof is that of beyond reasonable doubt. But in civil cases, when the penalties concern money for damages and suffering, the burden of proof is the preponderance of the evidence, which is understood to be more that one half. This distinction illustrates that in assessing proof we very often assess it against a background what is at stake. When what is at stake is a person's freedom or life, we expect more evidence than we do when what is at stake is money. Which seems to me right. This view is explored in a book by Jason Stanley, Knowledge and Practical Interests, who argues (according to the blurb) that "whether or not someone knows a proposition at a given time is determined by his practical interests, i.e. how much is at stake for that person at that time....".
 
Zetherin
 
Reply Thu 12 Nov, 2009 07:56 am
@fast,
Emil wrote:

The first is a general term and the second is used mostly in courts. I think proving is stronger than proving beyond a reasonable doubt. In other words: It is harder to prove something than to prove something beyond a reasonable doubt.


I agree. This is what I thought.

Quote:
Even tautologies (i.e. necessary truths) are not matters of epistemic certainty. Just try doing advanced math and you will see how fallible you are.


I did not know this. I thought tautologies, by definition, were necessary truths. And, I also thought mathematical equations were tautologies. And so then I thought it followed that mathematical equations were necessary truths.

How fallible I am, has nothing to do with a mathematical equation being a necessary truth. My inability to solve the equation doesn't mean that what's on the other end of that equal sign isn't the same as what's on the first end, just in a different form.

However, I have not done much advanced math, so, perhaps you are correct.

kennethamy wrote:

In American courts, the burden of proof depends on the kind of case being decided. In the instance of criminal cases, when the penalties concern the freedom or even the life of the accused, the standard of meeting the burden of proof is that of beyond reasonable doubt. But in civil cases, when the penalties concern money for damages and suffering, the burden of proof is the preponderance of the evidence, which is understood to be more that one half. This distinction illustrates that in assessing proof we very often assess it against a background what is at stake. When what is at stake is a person's freedom or life, we expect more evidence than we do when what is at stake is money. Which seems to me right. This view is explored in a book by Jason Stanley, Knowledge and Practical Interests, who argues (according to the blurb) that "whether or not someone knows a proposition at a given time is determined by his practical interests, i.e. how much is at stake for that person at that time....".


Good insight.
 
Emil
 
Reply Thu 12 Nov, 2009 08:09 am
@Zetherin,
Zetherin;103112 wrote:
I did not know this. I thought tautologies, by definition, were necessary truths. And, I also thought mathematical equations were tautologies. And so then I thought it followed that mathematical equations were necessary truths.


Hopefully you still think that. Perhaps you should read my post again. I did not say that they are not necessary truths.

Zetherin;103112 wrote:
How fallible I am, has nothing to do with a mathematical equation being a necessary truth. My inability to solve the equation doesn't mean that what's on the other end of that equal sign isn't the same as what's on the first end, just in a different form.


Right; Nothing I contest.

Zetherin;103112 wrote:
However, I have not done much advanced math, so, perhaps you are correct.


Your tone and wording implies that we disagree about something, but what is it that you think that we disagree about (here)? I disagree with nothing you have written here.

I said that something being a tautology (i.e. a necessary truth) does not imply that we are epistemically certain about it. People sometimes think this. I think that it is because they consider simple cases such as the truth of 1+1=2. They think they are epistemically certain about that and by extension/analogy think the same for other mathematical propositions (perhaps just true non-contingent propositions in general). But people are not very certain about a great deal of mathematical propositions. I just gave the example of advanced math. It might as well be advanced logic which also deals with non-contingent propositions.

---------- Post added 11-12-2009 at 03:12 PM ----------

kennethamy;103099 wrote:
In American courts, the burden of proof depends on the kind of case being decided. In the instance of criminal cases, when the penalties concern the freedom or even the life of the accused, the standard of meeting the burden of proof is that of beyond reasonable doubt. But in civil cases, when the penalties concern money for damages and suffering, the burden of proof is the preponderance of the evidence, which is understood to be more that one half. This distinction illustrates that in assessing proof we very often assess it against a background what is at stake. When what is at stake is a person's freedom or life, we expect more evidence than we do when what is at stake is money. Which seems to me right. This view is explored in a book by Jason Stanley, Knowledge and Practical Interests, who argues (according to the blurb) that "whether or not someone knows a proposition at a given time is determined by his practical interests, i.e. how much is at stake for that person at that time....".


Sounds like contextualism to me. Link and link.

Initially I don't think that knowledge has different levels of required strength of the evidence.
 
Zetherin
 
Reply Thu 12 Nov, 2009 08:25 am
@fast,
Emil wrote:
I said that something being a tautology (i.e. a necessary truth) does not imply that we are epistemically certain about it.

I apologize if it seemed as though I had a harsh tone. Really, I didn't, I just sometimes write very... gritty, without feelings (perhaps?). Once again, I'm sorry for this.

I suppose I am not understanding how, if we know something is a tautology, we are not epistemically certain about it. By "epistemic certainty", we are speaking of a knowledge claim, right? But, to me, it seems as though I do have knowledge that what is going to be on one side of an equation will be on the other side, albeit in another form (usually).
 
Emil
 
Reply Thu 12 Nov, 2009 08:32 am
@Zetherin,
Zetherin;103117 wrote:
I apologize if it seemed as though I had a harsh tone. Really, I didn't, I just sometimes write very... gritty, without feelings (perhaps?). Once again, I'm sorry for this.

I suppose I am not understanding how, if we know something is a tautology, we are not epistemically certain about it. By "epistemic certainty", we are speaking of a knowledge claim, right? But, to me, it seems as though I do have knowledge that what is going to be on one side of an equation will be on the other side, albeit in another form (usually).


No problem. Smile As long as I have the impression that you are not a moron (towards me) and are generally rational, then will be no problems in the future too.

No. Epistemic certainty is not the same as knowledge (or "a knowledge claim"). Though some people (infallibilists about knowledge) believe that if someone knows that p, then that someone is epistemically certain that p.
Other people (e.g. fast) believe that if someone is epistemically certain that p, then that someone knows that p.

Information about epistemic and psychological certainty.
 
Zetherin
 
Reply Thu 12 Nov, 2009 08:37 am
@fast,
Emil wrote:

No. Epistemic certainty is not the same as knowledge (or "a knowledge claim"). Though some people (infallibilists about knowledge) believe that if someone knows that p, then that someone is epistemically certain that p.
Other people (e.g. fast) believe that if someone is epistemically certain that p, then that someone knows that p.

Information about epistemic and psychological certainty.


Thank you for this. I'll look at it a little bit later (have to do a work presentation at the moment Sad) and see if I can understand epistemic certainty, as opposed to knowledge.

Just so you know, I'll probably be posting questions! I'm very interested in this sort of material. I find it paramount in my study of philosophy.
 
kennethamy
 
Reply Thu 12 Nov, 2009 08:43 am
@Emil,
Emil;103113 wrote:
Hopefully you still think that. Perhaps you should read my post again. I did not say that they are not necessary truths.



Right; Nothing I contest.



Your tone and wording implies that we disagree about something, but what is it that you think that we disagree about (here)? I disagree with nothing you have written here.

I said that something being a tautology (i.e. a necessary truth) does not imply that we are epistemically certain about it. People sometimes think this. I think that it is because they consider simple cases such as the truth of 1+1=2. They think they are epistemically certain about that and by extension/analogy think the same for other mathematical propositions (perhaps just true non-contingent propositions in general). But people are not very certain about a great deal of mathematical propositions. I just gave the example of advanced math. It might as well be advanced logic which also deals with non-contingent propositions.

---------- Post added 11-12-2009 at 03:12 PM ----------



Sounds like contextualism to me. Link and link.

Initially I don't think that knowledge has different levels of required strength of the evidence.


Yes, it is contextualism. Why wouldn't what is claimed to be known require (not have) different strengths of evidence. I have never thought that there is some general algorithm for deciding whether justification is adequate for knowing. What reason would there be to think so? The pragmatics of knowing seem to me to be as important as the semantics.

I agree with what you write about necessary truth and certainty. It is persons who can be certain (or fallible). Not propositions. So far as I can tell, all that can be meant by calling a proposition certain is that it is a necessary truth.
 
Emil
 
Reply Thu 12 Nov, 2009 08:52 am
@Zetherin,
Zetherin;103120 wrote:
Thank you for this. I'll look at it a little bit later (have to do a work presentation at the moment Sad) and see if I can understand epistemic certainty, as opposed to knowledge.

Just so you know, I'll probably be posting questions! I'm very interested in this sort of material. I find it paramount in my study of philosophy.


Then you are lucky because me ("I"?), kennethamy and fast have been discussing it a lot in the past! Smile I often wrote small essays to clarify issues that we encountered in our discussions.
 
Zetherin
 
Reply Thu 12 Nov, 2009 08:54 am
@Emil,
Emil;103123 wrote:
Then you are lucky because me ("I"?), kennethamy and fast have been discussing it a lot in the past! Smile I often wrote small essays to clarify issues that we encountered in our discussions.


Perhaps it's time I grabbed a logic textbook and joined the cool crowd :cool:
 
Emil
 
Reply Thu 12 Nov, 2009 08:58 am
@kennethamy,
kennethamy;103121 wrote:
Yes, it is contextualism. Why wouldn't what is claimed to be known require (not have) different strengths of evidence. I have never thought that there is some general algorithm for deciding whether justification is adequate for knowing. What reason would there be to think so? The pragmatics of knowing seem to me to be as important as the semantics.


I haven't given contextualism much thought (haven't had the time but I've encountered it before in discussions regarding the existence of an external world (See this, particularly #6)). But I agree that pragmatics is relevant for knowledge in some ways, just not that different contexts have different requirements for the strength for the evidence.

The reason I think we require stronger evidence in murder trials (and similar) is that there is more at stake. Generally, the more there is at stake, the more sure we want to be (and thus the stronger evidence we require). Because often if we are wrong much is lost, e.g. an innocent human life.

---------- Post added 11-12-2009 at 03:59 PM ----------

Zetherin;103124 wrote:
Perhaps it's time I grabbed a logic textbook and joined the cool crowd :cool:


Indeed. PM me your email and I will send you one in PDF. I call us the analytics. We even have a user group which is not of any use as far as I can tell.
 
kennethamy
 
Reply Thu 12 Nov, 2009 09:01 am
@Emil,
Emil;103123 wrote:
Then you are lucky because me ("I"?), kennethamy and fast have been discussing it a lot in the past! Smile I often wrote small essays to clarify issues that we encountered in our discussions.


"I". You had better see what Z. has to say before you call him lucky. Smile
 
Emil
 
Reply Thu 12 Nov, 2009 10:16 am
@kennethamy,
kennethamy;103129 wrote:
"I". You had better see what Z. has to say before you call him lucky. Smile


That's right. He could be the hitherto undiscovered super expert of epistemology! Quickly let him decide the contextualism issue so that he can work on the issue with foundational/coherentism debate, and the internalism/externalism debate and so on. blablabla. Wink
 
 

 
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