Arguing from negative proof

[4gold]

Several arguments are given in this forum from the position of negative proof:

[center]"God does not exist, because there is no proof of his existence."

"Evolution must be true, because there is no other theory that explains the evidence."

"Dark matter must exist, because there is no other way to explain the universe."[/center]

And then there are logical inferences we all make from the absence of evidence, or else we couldn't have arguments, such as:

[center]"Mathematics is consistent, even though its consistency cannot be proven."

"The scientific method is reliable, even though its reliability cannot be proven."

"The laws of logic are rational, even though its rationality cannot be proven."

"The rules of morality are the same for you and me, even though the rules cannot be agreed upon."[/center]

My questions are:

How convinced should we be by arguments made by negative evidence?

Is there any way, other than Bayesian inference, to interpret the validity of arguments made by negative evidence?

[Pi]

Without direct evidence the best that one can accomplish is 'a working hypothesis'. "Absence of proof is not proof of absence", however, absence of proof does not permit any logical conclusion.

But even "logical conclusions" are not based on evidence, right? I mean, from what I understand, there is no evidence that the laws of logic get us closer to the truth. We just presume they do.

It depends upon the subject matter. If I went to the Moon and found an abandoned shopping cart then I could start making some logical assumptions about how it got there. That is a step towards the 'truth'.
I would then investigate my assumptions and alter them, add new assumptions and/or eliminate earlier assumptions.

Logical conclusions do not require evidence to be 'logical'... they can be based on assumptions or premises.

for example:

*Only pink elephants go to city hall
*I am riding a purple elephant
Therefore, I am presently not going to city hall.

Yes, the laws of logic do get us closer to the truth.... even if only the elimination of other possibilities narrows the field of potential answers.

for example:

*There is a crashed airplane on my lawn
*the crashed airplane did not grow on my lawn
Therefore... it must have come from another source

[Furrowed Brow]

Essentially, any argument based on logic has to presume that logic gets us closer to the truth, even though there is no evidence that logic gets us closer to the truth -- am I reading you right?

Well...no...not quite. Logic as I am meaning is the study of valid and consistent argument/thinking. So it is not really a question of the truth of our arguments, as judged by some external reality, but whether we are thinking straight about a subject. Here's an example:

Andy has been left £10 million in Arthur’s will.
Anyone worth £10 million does not have to work.
Andy does not have to work.

A valid argument. But lets say...

Andy gives his £10 million away to charity.

Does Andy have to work? Answer: we don't know. Andy might already have £10 million of his own, maybe Andy was Arthur’s pet dog. We are no nearer to finding the truth to this question. Attention to the logic of the argument will show what we can and cannot deduce. If we get our logic right, then we are prevented from reaching invalid conclusions. Whether that means we are nearer to the truth of the matter is a different question.
Logic is concerned with the soundness or lack of soudness of an argument. Truth and falsity is a different question. Here is a true but unsound argument.

Hitler was German. - True
All Germans are Europeans. - True
Therefore Napolean was French. - True

(E.J. Lemmon Beggining Logic covers this point pp 1 -2)

All the elements of this argument are true, yet the argument is unsound.

[daedalus 2.0]

Yes, those arguments are horrible. They are Straw Men created by the likes of Strobbel, McDowell and other crappy Xian apologists who can't argue against real logic.

I think the OP should look at the Inference to Best Explanation to understand the real arguments. (Not to mention, the real claims that athiests, scientists and philosophers make regarding these subjects).

If Theists can't win an argument without creating a Straw Man, why are they Theists?
If their position is so strong, why wouldn't they seek out the strongest arguments against their position?

I challenge any Theist to bring their strongest argument to the table and see how it fares. I doubt any of the atheists here will turn it into a Straw Man but meet it head on.