Problem of Evil Argument Conclusion versus a "lack of belief".

[Joshua260]

Joshu260:"Question 1: Do you believe that the above argument is valid?"
Well yes.

Joshu260:"Question 2: If answer to #1 is "yes", then do you profess to know that God A does not exist or do you simply believe that God A does not exist?"
I'm not gnostic and I do not even want to have that discussion again.

That's fine. But since you answered yes to Q1, then instead of lacking any beliefs in relation to a god, you hold to an actual belief that God A in my example does not exist, correct?

 

[elopez]

I'm not following you either. Perhaps I'm just being stupid...

as written:

1. If A, then ~B. (if omni-God, then there can be no evil)
2. B (evil exists)
therefore
3. ~A (no omni-God)

reworded:

1. If B, then ~A (if evil exists then there is no omni-God)
2. B (evil exists)
therefore
3. ~A (no omni-God)

I fail to see the important difference between the first and second versions of this argument.

What am I failing to understand here?

I doubt that it is because you're stupid. The difference is hard to notice if you don't know what you're looking for. If you haven't studied logic, chances are you won't see the difference unless expalined. Notice how the first argument is affirming the consequent of premise 1 in bold:

1. If A, then ~B.

2. B.

Therefore:

3. ~A.

Argument A is structured as affirming the consequent, which in logic, is considered fallacious and an invalid structure of argument. The correct structure is in the form of denying the consequent or affirming the antecedent, which comes in the rewritten form of argument B:

1. If A, then ~B.

2. A.

Therefore:

3. ~B.

Argument B is affirming the antecedent, a valid form of argument known as modes ponens.

 

[elopez]

This is indeed fallacious. However, the argument can easily be reworded into a valid form.

Indeed it can. Then it becomes a matter of evidence and logical support for premise 1.

 

[UndercoverElephant]

Hi elopez

I doubt that it is because you're stupid. The difference is hard to notice if you don't know what you're looking for. If you haven't studied logic, chances are you won't see the difference unless expalined.

I have studied logic (at bachelor's degree level), I know exactly what I'm looking for, and it isn't there. You are using technical language incorrectly.

Notice how the first argument is affirming the consequent of premise 1 in bold:

1. If A, then ~B.

2. B.

Therefore:

3. ~A.

B is not affirming the consequent of premise 1. If is affirming the negative of the consequent, and that changes the logic.

From Wikipedia entry on "affirming the consequent"

1. If P then Q
2. Q
3. Therefore not P.

An argument of this form is invalid, i.e., the conclusion can be false even when statements 1 and 2 are true. Since P was never asserted as the only sufficient condition for Q, other factors could account for Q (while P was false).[1][2]

To put it differently, if P implies Q, the only inference that can be made is non-Q implies non-P. (Non-P and non-Q designate the opposite propositions to P and Q)

Note that in the wikipedia example, the consequent in question is Q, rather than not Q.

If you try to put our argument into the structure given in the wikipedia example, you'll find you can't do it without producing total nonsense.

Argument A is structured as affirming the consequent, which in logic, is considered fallacious and an invalid structure of argument. The correct structure is in the form of denying the consequent or affirming the antecedent, which comes in the rewritten form of argument B:

1. If A, then ~B.

2. A.

Therefore:

3. ~B.

Argument B is affirming the antecedent, a valid form of argument known as modes ponens.

This is true, but irrelevant.

It expands to

1. If omni-God then no evil.
2. omni-God

therefore

3. there is no evil.

In this example, we are asserting the existence of an omni-God in a premise, and logically concluding that evil exists. What is the point in doing that? We already know what evil exists, so what is the point in constructing a syllogism to prove it? What is in question is whether the omni-God exists, and in your revised version we are simply asserting that the omni-God exists as a premise!

 

[elopez]

Hi elopez

I have studied logic (at bachelor's degree level), I know exactly what I'm looking for, and it isn't there. You are using technical language incorrectly.

I admit I could be but can you explain further?

B is not affirming the consequent of premise 1. If is affirming the negative of the consequent, and that changes the logic.

The negative is the consequent. B is affirming it, even if it is a negative in premise 1.

From Wikipedia entry on "affirming the consequent"

Note that in the wikipedia example, the consequent in question is Q, rather than not Q.

If you try to put our argument into the structure given in the wikipedia example, you'll find you can't do it without producing total nonsense.

Would it matter if it is Q or not Q? Either way the consequent is still being affirmed, which is invalid.

 

[UndercoverElephant]

Hi again elopez.

Yes, it matters if it is Q or not Q. Perhaps it would help to give a real example of the fallacy you are talking about.

1. If P, then Q.
2. Q.
3. Therefore, P.

1. If the devil exists, then there will be evil.
2. There is evil.
3. Therefore the devil exists.

If you think about this, just in terms of normal English, you can see the fallacy. The logical problem is that the existence of the devil hasn't been exclusively set up as the only possible explanation for the existence of evil - it might just be that some humans are badly behaved.

Our argument is different in two ways. Firstly, the consequent of premise 1 is not Q rather than Q, and secondly the conclusion is not P instead of P.

1. If P, then not Q
2. Q
3. Therefore, not P.

1. If the omni-God exists, then there will be no evil
2. There is evil.
3. Therefore for the omni God does not exist.

Again, thinking about it in terms of normal English, you can see this is valid. The omni-God has been set up as logically inconsistent with the existence of evil. Premise 1 logically states that there can be no evil if the omni-God exists. It follows that if there is evil then the omni-God cannot exist.

Put another way: "If P, then not Q" means that P and Q are logically exclusive - it works both ways, so it already implies the reverse: "If Q, then not P". But "If P, then Q" is a one-way relationship - it does not imply the reverse "If Q, then P."

Do you see it now?

UE

 

[elopez]

Hi again elopez.

Yes, it matters if it is Q or not Q. Perhaps it would help to give a real example of the fallacy you are talking about.

I am still not sure if it matters. The bottom line is the consequent of a conditional statement is being affirmed. I believe what matters here is the structure of the argument itself, rather than the negating of the consequent.

If we go by what you're saying, and correct me if I'm wrong, we can say that affirming the consequent is valid when it is negated? If so, can you provide sources or something to again further expand on this? If not, it would seem you are still confused.

 

[UndercoverElephant]

Read it how I wrote it in plain English. I think the terminology is confusing you. You're looking at the symbols, but not thinking about the logic!

 

[elopez]

Read it how I wrote it in plain English. I think the terminology is confusing you. You're looking at the symbols, but not thinking about the logic!

I still do not believe I am confused here.

You said of argument B "Premise 1 logically states that there can be no evil if the omni-God exists" yet that actually is not what premise 1 states rather "If the omni-God exists, then there will be no evil." Notice how you're switching the conditionals. Stated in the former way, we have to affirm the antecedent, however, structured in the original way, we have to affirm the consequent.

You can switch the conditionals and argue using modus ponens, yet to argue from the original structure, the fact of the matter is that you have to affirm the consequent to reach the conclusion. You seem to be saying the exception to this formal fallacy is that the consequent is negated. I am not saying that couldn't be the case, just asking for sources as I am not aware of any that state such. If anything I doubt that is the exception and would prefer it verified by credential sources if it is.

 

[elopez]

Even in "plain English" the existence of God hasn't been exclusively set up as the only possible explanation for the non existence of evil. Hence, premise 1 isn't a biconditonal statement.

 

[Tinker Grey]

Our argument is different in two ways. Firstly, the consequent of premise 1 is not Q rather than Q, and secondly the conclusion is not P instead of P.

1. If P, then not Q
2. Q
3. Therefore, not P.

1. If the omni-God exists, then there will be no evil
2. There is evil.
3. Therefore for the omni God does not exist.
UE

This is modus tollens. http://en.wikipedia.org/wiki/Modus_tollens

It is a valid construction.

 

[UndercoverElephant]

I still do not believe I am confused here.

You said of argument B "Premise 1 logically states that there can be no evil if the omni-God exists" yet that actually is not what premise 1 states rather "If the omni-God exists, then there will be no evil." Notice how you're switching the conditionals.

It doesn't make any difference. I'm just rewording the same logical structure. Premise 1, as stated in the opening post:

"If an omnipotent, omniscient, and omnibenevolent god exists, then evil does not."

It doesn't matter if we say "does not" or "can not".

Stated in the former way, we have to affirm the antecedent, however, structured in the original way, we have to affirm the consequent.

I have no idea what you are talking about. We don't have to affirm either of them. Premise 1 just says that if the omni-God exists, then evil does not or can not, and it doesn't matter which, because the end result is the same.

You seem to be saying the exception to this formal fallacy is that the consequent is negated. I am not saying that couldn't be the case, just asking for sources as I am not aware of any that state such. If anything I doubt that is the exception and would prefer it verified by credential sources if it is.

Just think about it!!!

Here is the fallacy:

1. If the devil exists, then there will be evil.
2. There is evil.
3. Therefore the devil exists.

It's a fallacy because there might be some other reason there is evil - because premise 1 does not rule out other causes of evil.

Here is our argument

1. If the omni-God exists, then there [will be / can be / is] no evil.
2. There is evil.
3. Therefore for the omni God does not exist.

In this case, premise 1 really does rule something out - it rules out the possibility of the omni-God and evil both existing at the same time.

Premise 1 is logically identical to:

1: The omni-God and evil cannot co-exist.

I don't have a source for you, but my grasp on logic is pretty secure. Why should there be a source to explictly state that something which isn't affirming the consequent isn't invalid? Our argument is simply not an example of "affirming the consequent." We aren't affirming
the consequent - the consequent is "there is no evil" and we are affirming the opposite!

 

[elopez]

It doesn't make any difference. I'm just rewording the same logical structure. Premise 1, as stated in the opening post:

"If an omnipotent, omniscient, and omnibenevolent god exists, then evil does not."

It doesn't matter if we say "does not" or "can not".

Clearly I think it is you who is misunderstanding here.

It DOES make a difference. Switching the conditionals results in different rules of inference for premise 2. Again, if we go with the former way, we have to affirm the antecedent to reach the conclusion. If stated the original way, we have to affirm the consequent to reach the conclusion. It is a formal fallacy to affirm the consequent.

I have no idea what you are talking about. We don't have to affirm either of them. Premise 1 just says that if the omni-God exists, then evil does not or can not, and it doesn't matter which, because the end result is the same.

So you admit you are unaware of formal logic? What I'm talking about is formal logic. Specifically, a conditional statement, and more specifically, a hypothetical syllogism. You DO have to affirm something to reach the conclusion. .. What are you talkimg about??

 

[Eudaimonist]

Question 1: Do you believe that the above argument is sound?

No, I do not. Or, at least, I am uncertain that God A would necessarily prevent evil from happening. So, the Argument From Evil doesn't strike me as an airtight argument.


eudaimonia,

Mark

 

[Eudaimonist]

It DOES make a difference. Switching the conditionals results in different rules of inference for premise 2. Again, if we go with the former way, we have to affirm the antecedent to reach the conclusion. If stated the original way, we have to affirm the consequent to reach the conclusion. It is a formal fallacy to affirm the consequent.

In English, please. Can you explain in plain English how the argument fails? Can you provide a counter-example?


eudaimonia,

Mark

 

[elopez]

In English, please. Can you explain in plain English how the argument fails? Can you provide a counter-example?


eudaimonia,

Mark

Im talking about how the argument in the OP commits the formal fallacy of affirming the consequent. Other than that, the problem of evil I haven't spoke on.

 

[Conscious Z]

The argument is valid. That is obvious.

The argument is not sound, however. The faulty premise is the first one. No philosopher in the world believes the first premise is true, which is why the standard problem of evil argument has zero traction in the philosophical community. What does have traction, however, is the evidentiary problem of evil. Roughly speaking, it goes more like this:

1. If an omniscient, omnipotent, omnibenevolent god exists, then there is as little evil in the world as possible.
2. There probably isn't as little evil in the world as possible.
3. Therefore, it is probably that such a god does not exist.

The argument isn't designed to produce a conclusion that says a god is logically impossible, but rather that such a god is highly unlikely. I've given the quick and dirty version here, but it's enough to get a good idea of the argument.

It is very compelling, IMO.

 

[Conscious Z]

To believe something is to accept that it is true, i.e. corresponds to reality. Knowledge consists of non-contradictory, objectively identified facts of reality. So yes if I believe something then I also know it. I do think this argument is valid and sound.

Belief and knowledge are not synonymous. While your definition of belief is correct, your definition of knowledge is not. Knowledge is not merely "non-contradictory, objectively identified facts of reality." In order to have knowledge about proposition P, one must do the following:

1. Believe P
2. Have justification for P
3. P must be true
4. One must not be lucky in arriving at true belief P

You believe many things that you do not know. Everyone does.

 

[Conscious Z]

Now I am not saying there is absolutely no problem of evil, or that all arguments are invalid, however, logically speaking, this argument is indeed invalid. The structure of the argument is what is invalid. Instead of denying the consequent such as it is with the valid form of the argument modes tollens, this argument affirms the consequent, also known as the converse error. The conclusion could be false even given the two premises may be true.

You are confusing what it means to affirm the consequent. Affirming the consequent looks like this:

If a, then b
b
Therefore, a

That is not the same as what the OP is doing, which is this:

If a, then not-b
b
Therefore, not-a

That is logically valid. There is no way to affirm b without rejecting a.

 

[Conscious Z]

Good point.

The form of the argument, as currently written, is:

1. If A, then ~B.

2. B.

Therefore:

3. ~A.

How is that fallacious? If A, then not-B. If B is the case, A cannot be the case. This is not affirming the consequent.