Definition of evidence?

Originally posted by OdBod
Definition of evidence? [...] in religious discussions ...

...with Christians and Muslims:

evidence apparently can be verses from their religionist literature.

I have heard quotations from the Bible described as "empirical evidence" on this forum.

Originally posted by FMF
...with Christians and Muslims:

evidence apparently can be verses from their religionist literature.

I have heard quotations from the Bible described as "empirical evidence" on this forum.

Evidence seems interchangeable with proof also. They are not the same. There is considerable evidence that the Riemann hypothesis is true but no proof as yet.

Originally posted by OdBod
This word is used a great deal in religious discussion and seems to be interchangeable with the word faith.

Evidence (E) FOR X being true is an empirical observation that increases the likelihood of X.

The greater the increase in probability then the stronger the evidence.

Proof (evidential rather than mathematical) is evidence strong enough that the resultant
probability of X being true is now so high as to make it beyond all reasonable doubt that
X is true.

In other words, your probability for X being true must be higher after learning evidence E than it was
before you knew E.

If the probability of X is now lower then E was evidence against X.

If the probability hasn't changed then it was neither evidence for or against X.

The probability is given by Bayesian theory.


Someone's belief in a proposition being true is only evidence for that proposition actually being true
IF that persons belief is formed by a method likely to map truth to belief.

Faith is not a method likely to map truth to belief and thus no faith based belief in a proposition is
evidence for the truth of that proposition.

Originally posted by Kepler
42?

Maybe a catch 22. 😏

Originally posted by googlefudge
Evidence (E) [b]FOR X being true is an empirical observation that increases the likelihood of X.

The greater the increase in probability then the stronger the evidence.

Proof (evidential rather than mathematical) is evidence strong enough that the resultant
probability of X being true is now so high as to make it beyond all reasonable doubt t ...[text shortened]... d thus no faith based belief in a proposition is
evidence for the truth of that proposition.[/b]

Now faith is the substance of things hoped for, the evidence of things not seen.
(Hebrews 11:1 KJV)

Originally posted by RJHinds
Maybe a catch 22. 🙄

How.. wha... do you even know what catch 22 is?

Originally posted by googlefudge
Evidence (E) [b]FOR X being true is an empirical observation that increases the likelihood of X.

The greater the increase in probability then the stronger the evidence.

Proof (evidential rather than mathematical) is evidence strong enough that the resultant
probability of X being true is now so high as to make it beyond all reasonable doubt t ...[text shortened]... d thus no faith based belief in a proposition is
evidence for the truth of that proposition.[/b]

You know, when you go on like that, my eyes just roll back in my head and I can't focus.

Speak English, man!

😀

Originally posted by RJHinds
Now faith is the substance of things hoped for, the evidence of things not seen.
(Hebrews 11:1 KJV)

A well-known passage, to be sure, but I've always grumbled at the inclusion of the word "hope" in there. To me, it begs for a lack of faith if we simply "hope".

If God promises something to us, then it's going to happen. Since I then know it will happen, hope shouldn't enter into it. Do I really need hope that God will keep His word? I say "no" because it is already a done deal.

Originally posted by Suzianne
You know, when you go on like that, my eyes just roll back in my head and I can't focus.

Speak English, man!

😀

I thought I was... But I will give it another go.


(hypothetical)
You go to the doctor for cancer screening.

The doctor gives you a test that (for the sake of this hypothetical) tests for the presence of certain proteins.

(in this hypothetical) These proteins are very rarely found in people who don't have cancer, but they are almost
always found in people who do have cancer.

So a positive result in this test indicating that you have these proteins means that it is more likely (perhaps much more
likely) that you have cancer.
A negative result in this test indicating that you don't have these proteins means that it is less likely (perhaps much
less likely) that you have cancer.

Because there is a link between the presence of these proteins and the presence of cancer, finding these proteins
means that it is more likely that you do have cancer.

The probability you have of having cancer goes up.

Thus a positive result on this test is evidence that you have cancer.




Now looking at my last post the Proposition (P) here would be that "you have cancer".
The evidence (E) would be that "You have tested positive for the presence of these proteins"
And E is "Evidence For" P because the probability that "You have cancer" Given that "You have tested positive for these proteins"
is higher than the probability that "you have cancer" a priori.


Now lets say for example that the cancer rate for the demographic being screened is 10 in 100,000 (or 0.01% )

And lets also say that the proportion of people who DON'T have cancer who DO have these proteins is 91 in 100,000 (0.091% )

And lets say that the proportion of people who DO have cancer who DO have these proteins is 9 in 10 (90% )

Then your probability of having cancer a priori, simply by virtue of being in this demographic is 1 in 10,000 (0.01% )

You then take the test and it comes up positive for the presence of proteins.



Out of 100,000 people...

10 will have cancer, 9 of which will test positive for these proteins.

leaving 99,990 people who don't have cancer....

91 of which will test positive for these proteins. (I'm rounding to the nearest whole human for simplicity)



So out of the original 100,000 people 10 of which had cancer, you now have 100 people who have tested positive for these proteins...
9 of whom have cancer.

So by testing positive your new probability of having cancer is 9 in 100 (or 9% )

So a positive result on this test increases the probability that you have cancer from 0.01% to 9%
Which is an increase by a factor of 900.

(note that while a positive result in this test is evidence for your having cancer and increases the probability of your having cancer by a
factor of 900 over background... You still have a 91% chance of not having cancer after a positive result on this test... So while this test is
evidence of cancer, it is a long way shy of being proof.)


This test is thus evidence for you having cancer, as a positive result makes you 900 times more likely to have cancer than your chances
before you took the test.

Conversely a negative result means that your chances of having cancer are now 1 in 99,990 (0.001% ) or 10 times lower than before you
took the test.



So you can see that this a positive result on this test, by changing the probabilities for the likelihood that you have cancer, is evidence for your
having cancer.



However if the chances of you having cancer were independent of the presence of these proteins (if for example 37.5% of people without cancer
had them and 37.5% of people with cancer had them) then the probability of you having cancer after taking the 'test' would be exactly the same
as the probability of you having cancer before you took the 'test'.

In which case the 'test' wouldn't actually be providing any evidence for your having cancer, and wouldn't indeed even be called a test for cancer as
when we say something is a "test for something", "evidence for something", what we really mean is that it increases the probability of that something
being true.


The strength of the evidence is by how much the probability gets shifted.



Was that any clearer?

Originally posted by googlefudge
I thought I was... But I will give it another go.


(hypothetical)
You go to the doctor for cancer screening.

The doctor gives you a test that (for the sake of this hypothetical) tests for the presence of certain proteins.

(in this hypothetical) These proteins are very rarely found in people who don't have cancer, but they are almost
always f ...[text shortened]... how much the probability gets shifted.



Was that any clearer?

Yes, much clearer. Not sure I see a connection between this and anything else, but yes, what you just said is very clear.

So tell me again how this affects my faith? Especially since the lack of any empirical evidence doesn't affect my faith in the slightest. It wouldn't be faith otherwise.

Originally posted by Suzianne
Yes, much clearer. Not sure I see a connection between this and anything else, but yes, what you just said is very clear.

So tell me again how this affects my faith? Especially since the lack of any empirical evidence doesn't affect my faith in the slightest. It wouldn't be faith otherwise.

I appreciate that.

However there are people, even on these forums, who seem to believe that having
faith in something, that believing something really really hard, IS evidence.

A nonsense that you don't subscribe to (although you have your own nonsense which I will get to)
but that many people apparently do.


Also there are plenty of theists who claim to have presented (or be presenting) evidence that
god exists (or some other of their claims is true) when what they are presenting is not evidence
for their claims in the slightest.

RJHinds with his claims about the "Shroud of Turin" or the "Empty Tomb" or even claims that the bible
is evidence of god all fall into the category.

And so it's a reasonable discussion to talk about what evidence actually is/means.





Now I know that you believe that you believe based on pure faith and that you are not supposed to have
evidence for the existence of god because if you did have evidence for god you wouldn't be believing based
on pure faith... Which is kind of circular but lets press on...

You feel that we are supposed to believe in god based on faith alone and that only by doing this (and anything
else god requires) can we show ourselves worthy (or some such)...


You don't think you need evidence.


However this is nonsense.


If you have no evidence that a god or gods exists of any kind, then any possible god or gods could exist (or not).

There are in fact an infinite number of possible gods, including there actually being an FSM.

Without any evidence to pick one (or one set) out of the infinite pack your odds of picking the one that actually exists,
and this is making the rather large and unwarranted presumption that one/some DO actually exist, your chances of guessing
correctly are zero (makes mathematicians wince... sniggers).

And that's just for working out which god exists... we haven't even got to what they might want us to do.



Now of course you didn't pick the god of the bible at random.

There is a bible for starters, and lots of other people who believe (or think they believe) in the god described in it.
You live in a country dominated by people who believe in this god. (in one guise or another)

If you lived in another country (or even just community) dominated by another religion you would probably believe just
as wholeheartedly in that god, or those gods.

If you lived a couple of millennia in the past you would have believed in different gods yet again. (and they had lots to choose
from back then)


Now it's perfectly understandable that you have chosen to believe the religion of your society/family/country/ect...

But it's not rational, and that is no reason to suppose that it's actually true.


The bible is not evidence for god, neither is lots of people believing that it is or in the god described in it.

In fact with all it's flaws and traceable history it's actually evidence against the existence of your god being real as it's highly implausible
that a god with the powers and knowledge ascribed to the bible god in the bible would ever actually author the bible, or do the things
described in it.


So without any valid reason to pick Christianity, without any evidence, with just faith, you have effectively zero chance of being right.


it is thus irrational, and foolish, to believe that you are right.



And no amount of faith can ever change that... Only evidence can.





And I would note again that no god worthy of being worshipped would ever want to be worshipped let alone require it.
And no god worthy of worship would punish finite crimes with infinite punishment.
And no god worthy of worship would require belief without any evidence.