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The greatest proof of free will…
Posted: 14 May 2011 05:09 AM   [ Ignore ]   [ # 1066 ]
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GdB - 14 May 2011 04:58 AM

I think I have to give up.

Don’t you see that Mr X, who is a bachelor, if he would be married, would not be bachelor?

Don’t you see that I, who is married, if I would never have married, would be a bachelor?

If you stick to denying logic, I really start wondering if this is healthy… You are the hardest pupil I’ve ever had!

http://www.sfu.ca/~swartz/modal_fallacy.htm

Some writers prefer to call this fallacy “the modal scope fallacy” by which they mean that the fallacy consists of constricting the ‘scope’ of the necessity from the entire conditional (wide scope) to just its consequent (narrow scope). 

Which is what you did:

Antecedent                 ¦  Consequent
——————————————————¦————————————————-
If it is true that I am married   ¦  I cannot be a bachelor.   

Stephen

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Posted: 14 May 2011 05:34 AM   [ Ignore ]   [ # 1067 ]
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Wrong, nice try.

This is Schwartz’ first example:

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Paul has to have at least one son.

This is wrong indeed.

But this is correct:

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Paul has to have at least one son.

Do you seriously deny that Paul has a son?

Or do you just deny that he necessarily has a son?
With that I would certainly agree. But this is the form I need.

So let me reformulate more exact:
If I am married, I am not a bachelor.
If I never ... I could have been a bachelor.

You are just fly catching. I never meant, and you should understand that, that I said ‘I am necessarily married’.
I suppose, this is the point were you had problems:

If “I am married” is a truth, then, logically necessarily, “I am a bachelor” is false.

But what about the following sentence:

If Paul has one daughter and two sons, then he logically necessary has a son.

Does that mean that Paul necessary has a son? Couldn’t he have had just 3 daughters? Of course, there is no physical necessity for that!
This is not a modal fallacy.

Maybe you look at your necessitinarianism again? That there is a difference between logical and physical necessity?

[ Edited: 14 May 2011 05:38 AM by GdB ]
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Posted: 14 May 2011 05:42 AM   [ Ignore ]   [ # 1068 ]
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BTW, nice page of Norman Schwarz (Bryan advised it to you, didn’t he?):

Logical Determinism
Aristotle’s problem of tomorrow’s sea battle (here reconstructed and considerably embellished).

  “Two admirals, A and B, are preparing their navies for a sea battle tomorrow. The battle will be fought until one side is victorious. But the ‘laws’ of the excluded middle (no third truth-value) and of noncontradiction (not both truth-values), mandate that one of the propositions, ‘A wins’ and ‘B wins’, is true (always has been and ever will be) and the other is false (always has been and ever will be). Suppose ‘A wins’ is today true. Then whatever A does (or fails to do) today will make no difference; similarly, whatever B does (or fails to do) today will make no difference: the outcome is already settled. Or again, suppose ‘A wins’ is today false. Then no matter what A does today (or fails to do), it will make no difference; similarly, no matter what B does (or fails to do), it will make no difference: the outcome is already settled. Thus, if propositions bear their truth-values timelessly (or unchangingly and eternally), then planning, or as Aristotle put it ‘taking care’, is illusory in its efficacy. The future will be what it will be, irrespective of our planning, intentions, etc.”

(If the error is unobvious to you, click here.)

Maybe it helps you…

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Posted: 14 May 2011 05:52 AM   [ Ignore ]   [ # 1069 ]
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GdB - 14 May 2011 05:34 AM

This is Schwartz’ first example:

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Paul has to have at least one son.

This is wrong indeed.

rolleyes

It’s wrong but it is a valid argument so the first premise is false.

Stephen

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Posted: 14 May 2011 06:00 AM   [ Ignore ]   [ # 1070 ]
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StephenLawrence - 14 May 2011 05:52 AM
GdB - 14 May 2011 05:34 AM

This is Schwartz’ first example:

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Paul has to have at least one son.

This is wrong indeed.

rolleyes

It’s wrong but it is a valid argument so the first premise is false.

There is nothing wrong with the premise. But the first sentence is expresses a logical necessity, and the conclusion can be interpreted as physical necessity. And that is the fallacy. You obviously did not read the rest of my posting.

And it’s you who has problems with the logic. My only problem here is that I sometimes are not very precise in my expressions, and then you duck on it like a falcon on a mouse, missing everything I mean.

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Posted: 14 May 2011 06:04 AM   [ Ignore ]   [ # 1071 ]
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GdB - 14 May 2011 05:42 AM

Maybe it helps you…

Sorry missed, it on further reading. You should read the complete page. I recognise a lot of fallacies…

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Posted: 14 May 2011 06:07 AM   [ Ignore ]   [ # 1072 ]
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GdB - 14 May 2011 06:00 AM

There is nothing wrong with the premise.

The solution offered is that there is something wrong with the premise

As there is no equivocation between has to in the first premise and has to in the conclusion, your solution doesn’t work.

Stephen

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Posted: 14 May 2011 06:21 AM   [ Ignore ]   [ # 1073 ]
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StephenLawrence - 14 May 2011 06:07 AM
GdB - 14 May 2011 06:00 AM

There is nothing wrong with the premise.

The solution offered is that there is something wrong with the premise

As there is no equivocation between has to in the first premise and has to in the conclusion, your solution doesn’t work.

No. Schwartz (above I gave my explanation), is that the scope of the modal operator is shifting:

1. It is necessary that (if Paul has one daughter and two sons, then Paul has at least one son)

To:

2. If Paul has one daughter and two sons, then Paul necessarily (has at least one son).

Schwartz points out that 1 is the exact formulation, but we often write it as 2. But correctly interpreted, as most people do, Stephen,  there is no problem at all, and nobody will conclude that Paul necessarily has a son. I guarantee you in every possible world were somebody has 2 sons, he at least has one son.

[ Edited: 14 May 2011 06:26 AM by GdB ]
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Posted: 14 May 2011 06:23 AM   [ Ignore ]   [ # 1074 ]
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I think I like Schwarz:

If, however, one adopts a thoroughgoing descriptive view of natural laws, the problem of free will does not even arise. On the view I am proposing, there simply is no problem of free will.

May I call him as witness?

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Posted: 14 May 2011 06:34 AM   [ Ignore ]   [ # 1075 ]
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GdB - 14 May 2011 06:00 AM

There is nothing wrong with the premise. But the first sentence is expresses a logical necessity, and the conclusion can be interpreted as physical necessity. And that is the fallacy.

We can try and see.

If you are married then you cannot (logical necessity) be a bachelor

You are married

Therefore you cannot (logical necessity) be a bachelor

but you also say it is not logically necessary for you to be married

Nope this switch from logical necessity to physical necessity has nothing to do with it.

Stephen

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Posted: 14 May 2011 06:36 AM   [ Ignore ]   [ # 1076 ]
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GdB - 14 May 2011 06:23 AM

I think I like Schwarz:

If, however, one adopts a thoroughgoing descriptive view of natural laws, the problem of free will does not even arise. On the view I am proposing, there simply is no problem of free will.

May I call him as witness?

This has nothing to do with it.

Stephen

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Posted: 14 May 2011 06:38 AM   [ Ignore ]   [ # 1077 ]
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GdB - 14 May 2011 04:09 AM

Antecedent                   ¦  Consequent
——————————————————¦————————————————-
If it is true that I am married   ¦  I cannot be a bachelor.
——————————————————¦————————————————-                        ¦

You are missing the most basic facts of logic.

It’s a basic fact of logic that this is incorrect, yes?

Stephen

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Posted: 14 May 2011 06:55 AM   [ Ignore ]   [ # 1078 ]
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StephenLawrence - 13 May 2011 10:49 PM
Write4U - 13 May 2011 08:23 PM

The problem as originally posited is meaningless as it mixes fact with speculation.

No, speculation has nothing to do with it.

You must be one or the other is not speculation.

When I say if it is the case that you are married that is not speculation, I just point out the logical consequences.

Stephen

But we have already established that “I am married” is true, therefore “I could have been a bachelor” is speculation. I could have been a goat or an ant, but what has that to do with the factual condition of being married now?

StephenLawrence - 12 May 2011 01:44 AM
It’s a necessary condition of having free will that certain truths about the future could be false.

and

So the truth that you are married could be false, since you can’t be both married and a bachelor

That was my point.

(premise a) It is true that you are married (now)
(premise b)It can be true that you are a bachelor (in the future)

(conclusion)Which is the same as saying it can be false that you are married.

No, it is not the same.
By your own words, “you can’t be both married and a bachelor”. However I could be a bachelor in the future IF I decided to divorce my wife. But this introduces a new condition which changes the “current” true condition of “I am married” to a new true condition (a) where “I am no longer married”.
But that does not change (a) from being true now, only that (b) was true in the past and can be true in the future, but neither renders current (a) false.

[ Edited: 14 May 2011 07:09 PM by Write4U ]
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Posted: 14 May 2011 06:55 AM   [ Ignore ]   [ # 1079 ]
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StephenLawrence - 14 May 2011 06:38 AM
GdB - 14 May 2011 04:09 AM
Antecedent                       ¦  Consequent
---------------------------------¦---------------------------------
If 
it is true that I am married  ¦  I cannot be a bachelor.
---------------------------------
¦--------------------------------- 

You are missing the most basic facts of logic.

It’s a basic fact of logic that this is incorrect, yes?

No, of course not.

If I have 2 sons, I cannot have no son.
If I am married, I cannot be a bachelor.

Both are true as it can be, per definition, logically.

Try Schwartz’ method:
1. If I am married, I cannot be a bachelor.

Rewrite:
2. If I am married then I am necessarily not a bachelor.

Clearer formulation:
3. It is necessary that (if I am married then I am not a bachelor).

And then you, and you alone, choose the literary interpretation of 1, and conclude, with the fact that I am married, that I am saying:

4. I am necessarily married.

You put the modal fallacy in my mouth.

[ Edited: 14 May 2011 07:21 AM by GdB ]
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Posted: 14 May 2011 08:38 AM   [ Ignore ]   [ # 1080 ]
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GdB - 14 May 2011 06:55 AM
StephenLawrence - 14 May 2011 06:38 AM
GdB - 14 May 2011 04:09 AM
Antecedent                       ¦  Consequent
---------------------------------¦---------------------------------
If 
it is true that I am married  ¦  I cannot be a bachelor.
---------------------------------
¦--------------------------------- 

You are missing the most basic facts of logic.

It’s a basic fact of logic that this is incorrect, yes?

No, of course not.

If I have 2 sons, I cannot have no son.
If I am married, I cannot be a bachelor.

Both are true as it can be, per definition, logically.

Try Schwartz’ method:
1. If I am married, I cannot be a bachelor.

Rewrite:
2. If I am married then I am necessarily not a bachelor.

Clearer formulation:
3. It is necessary that (if I am married then I am not a bachelor).

And then you, and you alone, choose the literary interpretation of 1, and conclude, with the fact that I am married, that I am saying:

4. I am necessarily married.

You put the modal fallacy in my mouth.

Ok, your first answer was to do with equivocation between logical necessity I think the right term might have been relative necessity and physical necessity, which had nothing to do with it. You also brought up confusing reality with language which had nothing to do with it.

You finally brought up my taking a literal interpretation of 1, which I do accept as an answer, although when you draw a diagram and say this is basic logical truth it’s hardly surprising that I take it literally.

Anyhow I tentatively accept the modal scope fallacy isn’t a problem as I had thought.

Stephen

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