Can Logic Alone Prove Anything?

[Kyuuketsuki]

I am absolutely sick of theists using philosophy and logic alone to attempt to prove things ... right now that is Messenger.

I know that scientists use logic as a reasoning tool but they NEVER to my knowledge use it to say case-closed as these idiots do! IOW it can lead to a hypothesis but it cannot lead to a theory because it would be contrary to the scientific method and I maintain that nothing except the scientific method (with the possible exception of math) has ever "proven" a damn!

A good example would be the Higgs Boson particle which has been logically deduced but, and here's the key point these idiot theists don't get, they have spent and continue to spend millions (billions?) of Euros building the Large Hadron Collider in order to test the hypothesis and find out if the HB particle is real. Logic suggest the HB exists, the LHC is a means to test that logic.

The Kalam Cosmological Argument (essentially a first cause argument) is a prime example of how such logic fails because, based on the premises that everything that begins to exist has a cause and that the universe at some point began to exist, it concludes (with near perfect circular reasoning) that the universe must therefore have a cause. Even ignoring arguments based in quantum research the argument fails because it is possible the universe may always have existed (the uncaused cause) and that "beginning to exist" is a time based concept and time did not exist before the universe did. To speculate on what existed BEFORE the universe did is a little bit like asking what's south of the South Pole ... it's a stupidly pointless idea.

So my question to you is can logic alone can prove something and has it done so yet? Please note that that second part of the question is important ... if you are going to say it can I think you have to go further than mere assertion.

Kyu

[bowmore]

So my question to you is can logic alone can prove something and has it done so yet? Please note that that second part of the question is important ... if you are going to say it can I think you have to go further than mere assertion.

I guess you mean can logic alone prove something about reality?

[Kyuuketsuki]

I guess you mean can logic alone prove something about reality?

You're probably right

Kyu

[SSY]

My understanding is, that if your premise/axioms are 100% true, any good conclusions drawn from them, will be 100% true also.

Example,
All men are mortal
Socrates is a man
Socrates must be mortal

I suppose the problem as it relates to reality is that one could never be sure that the axiom is correct. Newtonian mechanics for example includes the assumption that the speed of light is infinite ( hence a lorrentz factor of 1 ). If this were true, Newtonian mechanics would be absolutley right, there would be no need for Special or General relativity. When the speeds you deal with are small compared to c, Newton's stuff is still amazingly precise.

So until we can be perfectly sure about the axioms we use, we can not be sure about the conclusions drawn within that system. I don't think you can get an axiom without at least some inductive reasoning, which leads to the possibility of the inclusion of an error/generalisation.

[bowmore]

I suppose the problem as it relates to reality is that one could never be sure that the axiom is correct.

Apart from that, there is no logical set of axioms that is consistent and complete (Gödel)

[AnnaM]

Logic is the only way to prove anything, though of course one must be correct in applying it.  There are some things which are necessarily true because their denial would entail a logical contradiction, however.  Non-contradiction and methodological individualism being two examples of things that can be proven solely by logic, without reference to specific empirical facts.

[Wechtlein Uns]

I think it's worth noting that we as logical human beings don't practice logic for its own sake. We never have, and never will. It makes sense then, that logic is to be used as a tool to aid human minds in coming up with consistent and reasonable "truths". These truths are important though, no because they are true, but because they are useful, right?

So, I think another side to the question might be to ask, "Is logic useful", and the answer of course, cut's right to the heart of the matter, I feel. I don't think it's all to important that we "prove" something absolutely using only logic. Indeed, that use of logic is neither useful nor enlightening. Logic is most useful in conjunction with data. Without data, your logic would just be a bunch of empty sets!

I'm sure you could prove then, something about the realm of logic, but it probably wouldn't be to useful to us humans, who live and breathe reality.

Logic is the only way to prove anything, though of course one must be correct in applying it. There are some things which are necessarily true because their denial would entail a logical contradiction, however. Non-contradiction and methodological individualism being two examples of things that can be proven solely by logic, without reference to specific empirical facts.

Anna, I think you're overestimating logic's importance. Also, the world would be in a sorry state indeed if logic were the only way to prove things. Logic, taken to it's extreme form, self destructs in either complete absolutism with no evidence for that conclusion, or the complete collapse of all solid things, turning the world into relativistic nothingness, which has evidence for it, but completely destroys our hopes.

I think however, that a middle ground may be found. Logic was never discovered to prove abstractions for thier own sake, but to satisfy the greeks curiousity about the world around them. Indeed, any logical analyses, if it is to be effective and useful, probably should be tempered by what we can observe in the real world. This is what science has done, and I feel it has proven remarkably effective in creating that middle ground so sought after.  

[Kyuuketsuki]

Logic is the only way to prove anything, though of course one must be correct in applying it.  There are some things which are necessarily true because their denial would entail a logical contradiction, however.  Non-contradiction and methodological individualism being two examples of things that can be proven solely by logic, without reference to specific empirical facts.

Yet there are no purely logical arguments that can prove things in the real world. At least I am unaware of any.

Kyu

[toadhall]

Well, has anyone actually proved the laws of logic are true? Assuming the laws of logic are non-applicable in this case?

[bowmore]

Well, has anyone actually proved the laws of logic are true? Assuming the laws of logic are non-applicable in this case?

through inductive reasoning ...

Yet you can question the validity of inductive reasoning as well.

[AnnaM]

Anna, I think you're overestimating logic's importance. Also, the world would be in a sorry state indeed if logic were the only way to prove things. Logic, taken to it's extreme form, self destructs in either complete absolutism with no evidence for that conclusion, or the complete collapse of all solid things, turning the world into relativistic nothingness, which has evidence for it, but completely destroys our hopes.

This sort of skepticism is nonsensically self-defeating.  All reason and real knowledge derive from doxastic consistency, and non-contradiction is the basis of doxastic consistency, as well as logic.  Knowledge 'outside' of logic is nonsense and contradictory.  Logic is the only means of conceiving of true and false, much less of actually holding something to be the case.

Positivism is retarded, pseudo-logical and self-contradictory.  Skepticism is the same, but worse.  Polylogism - 'alternative forms of reason' is utter nonsense.

[Sophus]

Can Logic Alone Prove Anything?

Nope. It takes a logical mind as well.

[Tom62]

Logic can prove that planes can't fly and that bullets can never hit a moving object. Computers run programs that are constructed with logical statements, nethertheless computers are not intelligent and occasionally behave irrational. Messenger tried to prove the illogical with logic and therefore failed miserably. There are many examples where logic bring us on wrong paths. Science is a good example of this, where older (logical) theories had to be abandoned, because new experiments showed that reality was different. An unproven logical statement is therefore just as much worth as a pile of BS.

[Kyuuketsuki]

Anna, I think you're overestimating logic's importance. Also, the world would be in a sorry state indeed if logic were the only way to prove things. Logic, taken to it's extreme form, self destructs in either complete absolutism with no evidence for that conclusion, or the complete collapse of all solid things, turning the world into relativistic nothingness, which has evidence for it, but completely destroys our hopes.

This sort of skepticism is nonsensically self-defeating.  All reason and real knowledge derive from doxastic consistency, and non-contradiction is the basis of doxastic consistency, as well as logic.  Knowledge 'outside' of logic is nonsense and contradictory.  Logic is the only means of conceiving of true and false, much less of actually holding something to be the case.

Positivism is retarded, pseudo-logical and self-contradictory.  Skepticism is the same, but worse.  Polylogism - 'alternative forms of reason' is utter nonsense.

Logic can prove that God exists therefore logic alone is bollocks. This is essentially what my opening post referred to.

Kyu

[X1L]

Hi all

Just want to enter this debate by saying that logic alone can not prove anything (neither in the field of science or theology). For logic to work you some starting premises (in mathematical language this would be you axioms for any mathematiciens out there following this). What science tries to do is take observable phenomenons, find pattens, and through logical reasoning draw conclusions about the phenomenons and make predictions about it's future state. Now this theory can not be proved to be true as you can never be sure of the accuracy of your original premise, however, by finding an exception outside of phenominen will disprove the theory and lead scientists to either refine or rethink the theory, but the longer the predictions hold, the more confident science is confident of their reasoning.

Hope this helps

All the best

Chris