What About Logic?

[shinbits]

Now, I want to let everyone who reads this thread know, that I am not arguing or trying to embarrase or out-do anyone who believes in evolution.

I'm just asking a question, because I don't know something, and I hope someone will be kind enough to help me. No negative comments.

Okay?

Alright....
Some of you may have heard things like "ireducible complexity", and things like "What are the chances of such and such being an accident?"

Well, use of these arguments doesn't use the aprove scientific method. But it does us logic.

I was wondering, and I'm not asking in any demeaning way--

is there a place for pure logic when considering evolution or creationism?

Just a guy wanting to know.

 

[alerj123]

There is always a place for pure logic. However, those questions have fundamental flaws.

The first one, the "what are the chances" argument is flawed because it assumes that evolution has a goal and that the goal is us. That is not the case. Yes, there was a very small chance that we, out of all the possible choices, arose. However, if another pathway was taken, if soemthing different then us happend, then you'd be saying "wow, what are the chances"

In the lotery, each person has a very small chance of winning, but someone always does. Same idea. Deal out 52 cards, the chance of those 52 cards falling in the exact order that they fell in is very small, but it happend.

The irreducibly complex argument fails because there hasn't been a structure that has been shown to be irreducibly complex. Yes, if such a structure was found then it would have serious problems for evolution. But so far it has not.

 

[PKJ]

"Ireductible complexity" uses logic in the same way the sophists did, i.e. a bad way:

p. Every system needs all its parts
q. Evolution adds parts one by one
r. Systems cannot evolve

Conclusion:
s. God is great, let's pray in school!

 

[Mystman]

logic always has a place in creationism/evolution.

however, just because you use logic to come to a conclusion (based on information), doesn't mean that the conclusion is correct (because the information you've used may be faulty/incomplete).

It's the same with for example the ireducible complexity argument. If there were indeed just a one in a gazillion chance of a "ireducibly complex" system coming into existence somewhere in the universe, at some point in time, than it would be "logical" to conclude that a whole series of such events is so unlikely that it is impossible.

However, the fault here lies with the used information. Because the chance of a ireducibly complex system arising is much, much larger.

 

[DJ_Ghost]

The problem with logic is that it nature often isn’t logical. Science studies nature, logic has its place in philosophy, but a good philosopher can argue any position using logic, and can then argue the exact opposite with logic. This tells us just what an imprecise tool logic can be.

For example, irreducible complexity sounds logical on the surface. How could a human eye work if we removed some of its vital components? Well it couldn’t but then that's not how evolution works, we actually see simpler forms of eye in nature and when we study them it suddenly hits us that IC isn’t as logical as it seemed, because it starts from an incorrect premise about what evolution claims.

Same thing with the “£couldn’t be an accident” argument. It sounds logical, but it assumes that Chemistry is random, and since chemistry isn’t random, we quickly relaise that the “couldn’t be an accident” argument is again illogical in itself.

So in summery, logic is an imprecise tool that can be used to argue that black is white by some one well versed in it, hence if you want to sturdy nature its not a good tool to do it with.

Ghost

 

[Deamiter]

Mystman has it exactly right. "Pure" logic is rather meaningless as logic is only useful when it's applied to current situations LIKE C&E. Logically, you can conclude whatever you like. The two things you pointed out are a wonderful example. As others have pointed out, the arguments can be very logically correct, and yet be dead wrong since they're based on false premises.

Irreducable complexity has never been shown to be unevolvable. There are certainly structures that are irreducably complex in that if one part were removed, they would no longer function. However, this ignores the fact that the parts are VERY useful for other functions... I have never yet been shown a structure that uses bits that are not and could not be part of another structure BEFORE the final form evolved.

As for the chance arguments, they invariably ignore that evolution is not a random process. Only mutations are relatively random (though even they aren't totally random by a long shot!) I'm sure you've heard of natural selection. It's an integral part of what creationists like to call "micro-evolution" so it's not really debated. Without any selecting force, there would BE no evolution. So again, the chance arguments may be logically sound, but what they're really "proving" is that evolution is near-impossible WITHOUT any sort of environment. As such, the conclusion is worthless as nothing exists without an environment!

 

[shinbits]

Some of you bring up good points.

But true logic can never be false. Otherwise, it isn't logic.

Logic proves itself by way of just existing.

For ex:
The fact that I am currently in the United States in front of a computer, proves that I am not skiing in the Alps.
In other words, the pure fact that I am in the US exists, proves that I am not in the Alps.

While it is true that some people twist logic to suit thier own agendas, pure logic really can't be twisted, and is always true.

As far as complexity is concerned, can logic be applied to this?

 

[notto]

As far as complexity is concerned, can logic be applied to this?

Only if the logical conclusion is that complexity can evolve because it has been observed to. I'm assuming that you accept that logic cannot violate observation.

 

[DJ_Ghost]

Some of you bring up good points.

But true logic can never be false. Otherwise, it isn't logic.

This isn’t so at all. Unlike science, logic can be used to investigate the metaphysical, the realm of abstract thought for example. It is not a case of “twisting it to fit” at all, a good philosopher can provide a logical argument for two competing metaphysical conclusions without twisting the logic.

For ex:
The fact that I am currently in the United States in front of a computer, proves that I am not skiing in the Alps.
In other words, the pure fact that I am in the US exists, proves that I am not in the Alps.

This example is very correct, however (since we are discussing logic) it is a logical fallacy to extend this example to all instances of the use of logic. You male to great an inductive leap here by claiming that because the argument holds true in this one observed instance it must also hold true in all unobserved instances.

Challenge a philosopher to logically demonstrate the existence of God some day, then challenge him to logically demonstrate the non-existence of god. A philosopher worth his salt should be able to use logic to argue for both conclusions. The key is in weather we are applying logic to the observable or the metaphysical I think. (In this instance I am using metaphysical in its broadest sense, not in its supernatural context).

As far as complexity is concerned, can logic be applied to this?

I am not sure it can, not in the way considered in the OP at least.

Ghost

 

[GoSeminoles!]

Something can be entirely logical yet still be incorrect if the assumptions are incorrect.

Assumption: All dogs have fleas.
Logic: Tycho is a dog, therefore Tycho has fleas.

Or does he? I just checked my dog Tycho and he does not have fleas. The logic is internally consistent but it leads to an incorrect conclusion because the assumption is wrong.

 

[shinbits]

This isn’t so at all. Unlike science, logic can be used to investigate the metaphysical, the realm of abstract thought for example. It is not a case of “twisting it to fit” at all, a good philosopher can provide a logical argument for two competing metaphysical conclusions without twisting the logic.

I see what you're saying. If you have time, do you think you could post an example of logic that isn't twisted, where all the premises are true, being used to prove both sides of opposing points of view?

If you could, then my question would basically be answered about the usefulness of logic.

Something can be entirely logical yet still be incorrect if the assumptions are incorrect.

Assumption: All dogs have fleas.
Logic: Tycho is a dog, therefore Tycho has fleas.

The only thing is, that one of the premises are wrong: All dogs have fleas.

Since this isn't true, the conclusion isn't a valid logical statement.

All the premises in a valid logical statement must be true.

One more question:

Is logic applied to the scientific method?


Thank you all for posting.

 

[DJ_Ghost]

I see what you're saying. If you have time, do you think you could post an example of logic that isn't twisted, where all the premises are true, being used to prove both sides of opposing points of view?

I don't think I could because I suck at philosophy, (I'm a social scientist) you need a philosopher for that. We used to have a couple kicking about, I don't know if they are still here or not.

Ghost

 

[DJ_Ghost]

.

All the premises in a valid logical statement must be true.

Not necessarily otherwise logic could not be used to argue metaphysics (where we don’t know if something is true because we can’t empirically test it). Rather, all the premises in a valid logical argument must not be false, which isn’t quite the same thing.

Ghost

 

[shinbits]

Only if the logical conclusion is that complexity can evolve because it has been observed to..

evolving complexity would definately be one conclusion. But would it really be the only one?

I'm assuming that you accept that logic cannot violate observation.

Yes.

As long as the observation is irevocably true.

 

[Kripost]

Some of you bring up good points.

But true logic can never be false. Otherwise, it isn't logic.

Logic proves itself by way of just existing.

Strictly speaking, logic can never prove itself. That itself is an undecidable problem.

 

[FSHWILDFIRE]

Strictly speaking, logic can never prove itself. That itself is an undecidable problem.

Doesn't Godel's Incompleteness theorem have anything to say about that?
I think it does. I remembering reading it awhile ago. Just being curious

 

[gluadys]

The only thing is, that one of the premises are wrong: All dogs have fleas.

Since this isn't true, the conclusion isn't a valid logical statement.

Yes, it is a valid logical statement. A valid logical statement is one that is a necessary conclusion of the premises. The statement is logically valid whether or not the premises are true.

Of course, in spite of being a validly logical conclusion, the conclusion will still be false if one or both of the premises are false.

In logic "valid" and "true" don't necessarily coincide.

Is logic applied to the scientific method?

It is applied in the scientific method, not to it. Part of the scientific method requires testing one's hypothesis. To create a test of one's hypothesis, one must deduce from the hypotheis something that we must observe in nature. In other words one must form a premise of the nature "if A (my hypothesis), then B (my predicted observation).

If one finds B, then A is supported (though not proven). If one finds not-B, then A is falsified, and must be either revised or rejected.

 

[Kripost]

Doesn't Godel's Incompleteness theorem have anything to say about that?
I think it does. I remembering reading it awhile ago. Just being curious

It is a consequence of Godel's Incompleteness theorem; second, if I remember correctly.

 

[Gracchus]

If all the premisses in an argument are true,
AND the rules of inference are correctly applied,
THEN the conclusion must be true.

In logic, all arguments that are not tautologies (if and only if 'a' then 'a') are contingent. That is: The conclusion is proven only if the premisses are true.

This being so, we can use logic to test the truth of the premisses. If we apply the rules of inferences correctly and obtain a false conclusion, then we have proved at least one of the premisses is untrue. This is called reductio ad absurdum, and it is a powerful tool of logic.

Metaphysical or supernatural premisses can seldom be tested in this way, and in religion people assume whatever conclusions they prefer, and make up premisses to fit their biases. Of course sometimes they arrive at absurd conclusions, such as omniscient, omnipotent, just and merciful God who destroys the innocent with the guilty, a loving father who allows his children to be tortured or tortures and abuses them himself. That is truly absurd.

It is because we believe absurdities that we are able to commit atrocities.

--- Voltaire

When I run across some one spouting absurdities I know they shouldn't be trusted around children, because they are laying a basis for evil actions. Christians and patriots are common examples.

 

[tocis]

Some of you may have heard things like "ireducible complexity", and things like "What are the chances of such and such being an accident?"

Well, use of these arguments doesn't use the aprove scientific method. But it does us logic.
is there a place for pure logic when considering evolution or creationism?

Yes it uses logic... but it's based on wrong initial claims.

As Boolean logic goes: When you start from something false you can conclude everything. It doesn't matter.

That said, yes there definitely is a place for logic in the science/creationism charade.