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What is evidence?

Welfare-Worker
Posts: 1,181
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10/22/2016 2:18:49 PM
Posted: 1 month ago
I see a lot of confusion on this board about the meaning of the term 'evidence'.

Most of this comes from those who have a Science based belief system, undoubtedly due to their narrow minded view of of language. They seem to be under the mistaken view that every discipline, and every person, should accept the language of Science.

There is a term - 'Scientific evidence' - that is commonly accepted language in all disciplines.
Those with science based belief systems seem to think that 'scientific evidence' is just another way of saying 'evidence'. This is a false belief.

Evidence is something that convinces a mind concerning the the truth of something.
Legal evidence will convince certain minds, but not others.
Religious evidence will convince certain minds, but not others.
Scientist evidence will convince certain minds but not others.

Logical evidence is not the same as Scientific evidence.
Logic is a tool of philosophy, borrowed by all of the other disciplines, Science included.
Many logical arguments, that are valid, and would convince many minds, may fail tests of scientific evidence.
A scientific belief system may reject them, because the premises could not be shown to be Scientifically true. They would not have the support of Scientific evidence.
This would be of concern to those with a Science based belief system, but not others.
Logic, takes priority over Science, for many of those with Science based belief systems.
To them, Science is the highest principle, over logic.
With their myopic worldview, they will deny this, and try to explain things so that they could never be seen as illogical. However, they will always refer back to their precious Scientific evidence, to explain their logic.
Science on top, logic secondary, that is how they will explain things.

If I experience something, and know, with certainty that it happened, that is all the evidence I need, but it will fail if tested by science standards.
I like Scientific evidence, for some things. It is not always trustworthy, often it is wrong, but eventually they will get it right. I evaluate Scientific evidence, and judge it, based on my own guidelines.
When my doctor told me the Scientific evidence was clear, and I did not a kidney stone, I knew the evidence was mistaken, false. Eventually the science got it right, and my huge kidney stone was removed.
When it comes to my body, some things are known to me, that Science will deny, once, twice, before it finally gets it right.
The same with my mind.
keithprosser
Posts: 2,045
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10/22/2016 3:12:14 PM
Posted: 1 month ago
I can't see where you tell us what scientific evidence is!

I am prepared to offer this definition: "Scientific evidence is a set of carefully checked observations".

An observation that is made but not checked is 'evidence', but it is very poor quality evidence and can be ignored if there is a good reason to. But if an observaton is made repeatedly and shows good replicability it is good quality evidence and can't be lightly ignored.

There is a big difference between "evidence" and "proof". Evidence suggests something is true (or something is false) to a lesser or greater degree of confidence depending on its quality. Proof is evidence of such high quality that it is unreasonable to suppose what it suggests is true (or suggests is ruled out) is not the case.

in science (as opposed to logic and mathematics), it is almost impossible to prove some conjecture is true with the same rigour something is provable in maths or logic. The reason is that 'scientific truths' are arrived at by induction. not deduction. Induction is the making of a conclusion from a finite number of observations, such as noting every swan you see is white and concluding all swans are white. Such inferences are - from a logician's persective - unsafe or 'invalid' in their terms.

I'd say the easiest way to think about it is to treat the term 'scientific truth' as referring to something that is consistent with everything that has been observed so far. More generally, a scientific truth is either a) a carefully checked observation or b) something consistent with all the carefully checked observations made so far.

That is a much weaker version of 'truth' than the one used by logicians and mathematicians. The reason for the difference is that logicians and mathematians have the luxury of being able to define the elements in their 'universe of discourse'. They get to say what a number is, what a set is and what the operatons of 'addition', and 'insersection' do. Scientists do not get to do that. Their 'universe of discourse' is the real universe of atoms and gravity, of electons and magnetism which are defined by the universe itself, not by the scientists investigating it.

A mathematician can speak of 'all integers' because all integers conform to the rules as defined by mathematicians, but a scientists cannot speak of 'all electons' because it is only possible to examine a subset of all electrons. Maths and logic can use deduction - science must use induction.
Welfare-Worker
Posts: 1,181
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10/22/2016 5:39:35 PM
Posted: 1 month ago
At 10/22/2016 3:12:14 PM, keithprosser wrote:
I can't see where you tell us what scientific evidence is!

I am prepared to offer this definition: "Scientific evidence is a set of carefully checked observations".

This definition would also work for recognized miracles of the Catholic Christian church.
There really shouldn't be any doubt in your mind that such events are "carefully checked".
This is the problem with most of what I read in your post. You use words or terms you believe have only one meaning, when they have many.

If I may suggest, what you mean is, "observations carefully checked by Scientific standards".

The Catholic standards for determining what events can be considered a miracle are truly quite rigorous. It is no easy matter.

I see no benefit in commenting on the remainder of your post at this time. It is really just more of the same.
I perhaps should point out that it is the nature of mircles that they cannot be repeated.
I will also point out that supernatural events are beyond the understanding of Science.
The prediction is, Science may find no acceptable (to its standards) evidence.

An observation that is made but not checked is 'evidence', but it is very poor quality evidence and can be ignored if there is a good reason to. But if an observaton is made repeatedly and shows good replicability it is good quality evidence and can't be lightly ignored.

There is a big difference between "evidence" and "proof". Evidence suggests something is true (or something is false) to a lesser or greater degree of confidence depending on its quality. Proof is evidence of such high quality that it is unreasonable to suppose what it suggests is true (or suggests is ruled out) is not the case.

in science (as opposed to logic and mathematics), it is almost impossible to prove some conjecture is true with the same rigour something is provable in maths or logic. The reason is that 'scientific truths' are arrived at by induction. not deduction. Induction is the making of a conclusion from a finite number of observations, such as noting every swan you see is white and concluding all swans are white. Such inferences are - from a logician's persective - unsafe or 'invalid' in their terms.

I'd say the easiest way to think about it is to treat the term 'scientific truth' as referring to something that is consistent with everything that has been observed so far. More generally, a scientific truth is either a) a carefully checked observation or b) something consistent with all the carefully checked observations made so far.

That is a much weaker version of 'truth' than the one used by logicians and mathematicians. The reason for the difference is that logicians and mathematians have the luxury of being able to define the elements in their 'universe of discourse'. They get to say what a number is, what a set is and what the operatons of 'addition', and 'insersection' do. Scientists do not get to do that. Their 'universe of discourse' is the real universe of atoms and gravity, of electons and magnetism which are defined by the universe itself, not by the scientists investigating it.

A mathematician can speak of 'all integers' because all integers conform to the rules as defined by mathematicians, but a scientists cannot speak of 'all electons' because it is only possible to examine a subset of all electrons. Maths and logic can use deduction - science must use induction.
sdavio
Posts: 1,798
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10/22/2016 6:44:37 PM
Posted: 1 month ago
Evidence is any fact which inferentially increases the probability of a given proposition.
"Logic is the money of the mind." - Karl Marx
Welfare-Worker
Posts: 1,181
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10/22/2016 8:39:19 PM
Posted: 1 month ago
At 10/22/2016 6:44:37 PM, sdavio wrote:
Evidence is any fact which inferentially increases the probability of a given proposition.

What is a fact?
sdavio
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10/23/2016 2:17:10 AM
Posted: 1 month ago
At 10/22/2016 8:39:19 PM, Welfare-Worker wrote:
At 10/22/2016 6:44:37 PM, sdavio wrote:
Evidence is any fact which inferentially increases the probability of a given proposition.

What is a fact?

A true proposition.
"Logic is the money of the mind." - Karl Marx
Welfare-Worker
Posts: 1,181
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10/23/2016 10:44:10 AM
Posted: 1 month ago
At 10/23/2016 2:17:10 AM, sdavio wrote:
At 10/22/2016 8:39:19 PM, Welfare-Worker wrote:
At 10/22/2016 6:44:37 PM, sdavio wrote:
Evidence is any fact which inferentially increases the probability of a given proposition.

What is a fact?

A true proposition.

And how does one a proposition is true?
Welfare-Worker
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10/23/2016 10:48:04 AM
Posted: 1 month ago
At 10/23/2016 10:44:10 AM, Welfare-Worker wrote:
At 10/23/2016 2:17:10 AM, sdavio wrote:
At 10/22/2016 8:39:19 PM, Welfare-Worker wrote:
At 10/22/2016 6:44:37 PM, sdavio wrote:
Evidence is any fact which inferentially increases the probability of a given proposition.

What is a fact?

A true proposition.

And how does one a proposition is true?

Should read: How does one determine a proposition is true?
Dirty.Harry
Posts: 1,585
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10/23/2016 1:54:25 PM
Posted: 1 month ago
I too think this is an important point, especially when debating at the science/theology interface.

I've seen numerous arguments that contain the phrase "this is evidence for" where in reality what should have been written was "this observation is consistent with".

Data can be consistent with some hypothesis yet not constitute evidence for it, for example the fact that certain presumably related species share genetic similarities is consistent with evolution but not evidence for it, there may well be other reasons for these observed similarities and unless these can be ruled out the observation is not evidence for it.
Welfare-Worker
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10/23/2016 3:09:35 PM
Posted: 1 month ago
At 10/23/2016 1:54:25 PM, Dirty.Harry wrote:
I too think this is an important point, especially when debating at the science/theology interface.

I've seen numerous arguments that contain the phrase "this is evidence for" where in reality what should have been written was "this observation is consistent with".

Data can be consistent with some hypothesis yet not constitute evidence for it, for example the fact that certain presumably related species share genetic similarities is consistent with evolution but not evidence for it, there may well be other reasons for these observed similarities and unless these can be ruled out the observation is not evidence for it.

It seems to me there can always be other possible reasons, and how do we rule them out? With evidence, I assume.

On the surface there seems to me to be an infinite regression, in many cases, surely not all.
The evidence for any claim depends on the evidence for other claims, and for the other claims, etc, etc .

Another issue:
Is there no evidence for man-made global warming, if other causes have been suggested, and they have not been ruled out?

Or:
If it is the case that other causes can be shown to be true causes, but some people say there are multiple causes, man-made included, would you say there is no evidence for man-made causes, since other possibilities have been shown as actual?
keithprosser
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10/23/2016 5:47:25 PM
Posted: 1 month ago
I'm thinking about whether we should think in terms of 'evidence' and 'no evidence' in a black and white sort of way or if we should think in terms of 'quality of evidence', ie evidence coming in 'shades of gray'.

I also think we can't think of evidence independently of a theory or hypothesis. A piece of evidence an be be 'good quality' or 'strong' evidence in favour of one theory, weakly in favour of another and disproof of yet another - but we can't really speak of the quality of a piece of evidence abstracted from the theory it is evidence for or against.

Put another way, until you have a theory you can't seak of 'evidence'. What you can do is take a bunch of observations and formulate a hyothesis on tre basis of those observations. At that point those observations become evidence (of varyng quality), but unless you tell me the theory then I can't judge whether an observation is evidence at all.
Welfare-Worker
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10/23/2016 6:12:35 PM
Posted: 1 month ago
At 10/23/2016 5:47:25 PM, keithprosser wrote:
I'm thinking about whether we should think in terms of 'evidence' and 'no evidence' in a black and white sort of way or if we should think in terms of 'quality of evidence', ie evidence coming in 'shades of gray'.

I also think we can't think of evidence independently of a theory or hypothesis. A piece of evidence an be be 'good quality' or 'strong' evidence in favour of one theory, weakly in favour of another and disproof of yet another - but we can't really speak of the quality of a piece of evidence abstracted from the theory it is evidence for or against.

Put another way, until you have a theory you can't seak of 'evidence'. What you can do is take a bunch of observations and formulate a hyothesis on tre basis of those observations. At that point those observations become evidence (of varyng quality), but unless you tell me the theory then I can't judge whether an observation is evidence at all.

That is a very unusual position.
Courts of law define evidence, regardless of the theory being presented.
Would you say they are mistaken, and need to change how the courts operate, in regards to evidence?
keithprosser
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10/23/2016 6:47:07 PM
Posted: 1 month ago
I didn't realise you meant 'Evidence' as it applies in the court system. I was talking more about evidence as in 'evidence for evolution', 'Evidence of the historical Jesus' or evidence for 'Dark matter'.

I know nothing of the law so i will abstain from further comment.
Welfare-Worker
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10/23/2016 10:23:53 PM
Posted: 1 month ago
At 10/23/2016 9:09:54 PM, Benshapiro wrote:
"Evidence" is information that indicates whether a proposition is true or false.

Is information that appears as evidence regarded the same by all people?
Is it self evident, or dependent on the observer?
Benshapiro
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10/23/2016 11:49:28 PM
Posted: 1 month ago
At 10/23/2016 10:23:53 PM, Welfare-Worker wrote:
At 10/23/2016 9:09:54 PM, Benshapiro wrote:
"Evidence" is information that indicates whether a proposition is true or false.

Is information that appears as evidence regarded the same by all people?

No

Is it self evident, or dependent on the observer?

Extracting the informational content is dependent on the observer but the existence of this information is not.
Welfare-Worker
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10/24/2016 12:41:55 AM
Posted: 1 month ago
At 10/23/2016 11:49:28 PM, Benshapiro wrote:
At 10/23/2016 10:23:53 PM, Welfare-Worker wrote:
At 10/23/2016 9:09:54 PM, Benshapiro wrote:
"Evidence" is information that indicates whether a proposition is true or false.

Is information that appears as evidence regarded the same by all people?

No

Is it self evident, or dependent on the observer?

Extracting the informational content is dependent on the observer but the existence of this information is not.

So, information may seem to be the holy trail of evidence to one person, and garbage to another person?
Benshapiro
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10/24/2016 12:56:04 AM
Posted: 1 month ago
At 10/24/2016 12:41:55 AM, Welfare-Worker wrote:
At 10/23/2016 11:49:28 PM, Benshapiro wrote:
At 10/23/2016 10:23:53 PM, Welfare-Worker wrote:
At 10/23/2016 9:09:54 PM, Benshapiro wrote:
"Evidence" is information that indicates whether a proposition is true or false.

Is information that appears as evidence regarded the same by all people?

No

Is it self evident, or dependent on the observer?

Extracting the informational content is dependent on the observer but the existence of this information is not.

So, information may seem to be the holy trail of evidence to one person, and garbage to another person?

Yup. People who believe that the earth is flat think that the information supporting a spherical earth is garbage.