Deductive and inductive arguments

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kennethamy
 
Reply Sat 16 Jan, 2010 04:35 pm
@Kielicious,
Kielicious;120560 wrote:
I never said ALL. Quote me.


I did quote you. So now you are denying you meant that all deductive arguments have true premises, and that all deductive arguments have conclusions that follow from their premises? I see. Pretty lame. What did you mean, then? Explain. And make it good.
 
Kielicious
 
Reply Sat 16 Jan, 2010 04:42 pm
@kennethamy,
kennethamy;120561 wrote:
I did quote you. So now you are denying you meant that all deductive arguments have true premises, and that all deductive arguments have conclusions that follow from their premises? I see. Pretty lame. What did you mean, then? Explain. And make it good.



I never said ALL. Once again, quote me where I said ALL.

Edit: still waiting ken.
 
Emil
 
Reply Sat 16 Jan, 2010 09:20 pm
@kennethamy,
kennethamy;120484 wrote:
But the intention theory does not make the distinction between deduction and induction depend on psychology. The distinction is still logical between whether the argument is conclusive or not. Where intention comes in is in trying to decide whether the argument is deductive or inductive. That is an epistemological issue, not a logical issue. Intention theory does not psychologize logic (Frege's bid bugaboo). It may psychologize the epistemology of logic, though. But is that so bad?


You got it wrong. What I call intention theory does make the distinction depend on facts about human psychology. Maybe you have some other theory besides the two about how to explain the distinction. I don't.
 
kennethamy
 
Reply Sat 16 Jan, 2010 09:22 pm
@Kielicious,
Kielicious;120564 wrote:
I never said ALL. Once again, quote me where I said ALL.

Edit: still waiting ken.


No, you did not say, "all". But did you really mean "some"? Then why didn't you say so? Lame.
 
Emil
 
Reply Sat 16 Jan, 2010 09:29 pm
@Pyrrho,
Pyrrho;120485 wrote:
I think you need to articulate precisely what you mean by "the intention theory", as I do not believe that is what I stated at all.

When speaking with others, one is trying to understand what they mean (well, hopefully!). So that when a person is presenting an argument, one is interested in figuring out what the person means, so that one does not waste time on an argument that is irrelevant to what the person intends. This, however, does not make the argument, in itself, dependent upon intentions, as when trying to understand a mathematical problem someone is telling one about, one needs to understand the person in order to understand what math problem it is, but once one knows this, the persons intentions become irrelevant. 2 + 2 = 4, regardless of anyone's intentions, and arguments of the form[INDENT][INDENT][INDENT][INDENT]If P then Q
P
________
Therefore Q[/INDENT][/INDENT][/INDENT][/INDENT]are deductively valid regardless of anyone's intentions.


Ok. No major disagreements.

But I don't know what "This, however, does not make the argument, in itself, dependent upon intentions" means.

Pyrrho;120485 wrote:
Looking at your post at

http://www.philosophyforum.com/philosophy-forums/branches-philosophy/logic/7330-deductive-inductive-arguments-2.html#post120455

it becomes clear that I am not advocating your "intention theory" at all ("An argument is deductive iff it is intended by the arguer to be deductive."), for the deductive validity of Modus Ponens (the argument form above, for those who don't know) is not in any way dependent upon what someone intends. Modus Ponens is a deductive form of argument, regardless of how anyone intends it to be taken.


I agree that the argument above is valid (= "deductively valid"), but that does not imply that it is deductive. So, you beg the question when you write "Modus Ponens is a deductive form of argument, regardless of how anyone intends it to be taken.".

This is what is at issue. I'm not endorsing any specific theory. Maybe you have a third theory on the matter? That's good. But it would be better if you told us about it.
 
kennethamy
 
Reply Sat 16 Jan, 2010 09:34 pm
@Emil,
Emil;120593 wrote:
Ok. No major disagreements.

But I don't know what "This, however, does not make the argument, in itself, dependent upon intentions" means.



I agree that the argument above is valid (= "deductively valid"), but that does not imply that it is deductive. So, you beg the question when you write "Modus Ponens is a deductive form of argument, regardless of how anyone intends it to be taken.".

This is what is at issue. I'm not endorsing any specific theory. Maybe you have a third theory on the matter? That's good. But it would be better if you told us about it.


If the argument is deductively valid, then why doesn't that imply it is a deductive argument? How can it be a deductively valid argument, but not be a deductive argument? If someone intends it to be inductive, he has the wrong argument. Suppose I intend an addition to be a subtraction. Would that make the addition a subtraction?
 
Emil
 
Reply Sat 16 Jan, 2010 09:38 pm
@Zetherin,
Zetherin;120516 wrote:
Hm, I thought you could have inferred what I meant by my question.

I'll rephrase.

Can you explain why you came to that conclusion in the first place?

Thanks, that clears it up a bit. I still don't quite get it, but I'll do more research.


But I didn't come to the conclusion. I do not accept the analogy, I merely mentioned it because it seems that some people find it convincing (eg Kritikos though to be fair he did not write it at all, I inferred it from some of what he wrote).

Kennethamy is talking about a different intention theory that I am talking about. The one in my essay is not merely methodological (not "epistemological", Ken), as in how to decide whether an argument is deductive or inductive. It is a theory of what a deductive and inductive argument is.
 
kennethamy
 
Reply Sat 16 Jan, 2010 09:44 pm
@Emil,
Emil;120597 wrote:
But I didn't come to the conclusion. I do not accept the analogy, I merely mentioned it because it seems that some people find it convincing (eg Kritikos though to be fair he did not write it at all, I inferred it from some of what he wrote).

Kennethamy is talking about a different intention theory that I am talking about. The one in my essay is not merely methodological (not "epistemological", Ken), as in how to decide whether an argument is deductive or inductive. It is a theory of what a deductive and inductive argument is.


But we already have a theory of that which seems to be satisfactory. A deductive argument is, if correct, a conclusive argument. A non-deductive argument is, if correct, a non-conclusive argument.
 
Emil
 
Reply Sat 16 Jan, 2010 09:50 pm
@kennethamy,
kennethamy;120596 wrote:
If the argument is deductively valid, then why doesn't that imply it is a deductive argument? How can it be a deductively valid argument, but not be a deductive argument? If someone intends it to be inductive, he has the wrong argument. Suppose I intend an addition to be a subtraction. Would that make the addition a subtraction?


Because according to the intention theory iff the arguer intended an argument to be inductive, then it is inductive. And some arguers intend that a valid argument is inductive. Thus, there is a valid inductive argument.

So by saying that you are merely begging the question against the intention theory.

I don't think the deductive induction distinction is analogous to the addition subtraction distinction. That remains to be argued.

---------- Post added 01-17-2010 at 04:53 AM ----------

kennethamy;120598 wrote:
But we already have a theory of that which seems to be satisfactory. A deductive argument is, if correct, a conclusive argument. A non-deductive argument is, if correct, a non-conclusive argument.


Where can I read about that theory? It was not mentioned in the IEP article. The IEP article clearly presumes the intention theory.

What does "correct deductive argument" mean?

What does "correct non-deductive [inductive?] argument" mean?

What does "conclusive argument" mean?

What does "inconclusive argument" mean?
 
fast
 
Reply Sun 17 Jan, 2010 09:52 am
@Emil,
Emil;120390 wrote:
Your language use is peculiar. I don't want to discuss this odd view you have about negation suffixes ("-un", "-in" etc.). In this thread "invalid" means "not valid". I stipulate it as I have no patience to go through another case of your (or Ken's) personal language use. (Recall the case with "unjustified" and "not justified"?)

To say of an argument that it's invalid implies that the argument is deductive. To say of an argument that it's not valid implies no such thing.

And yes, as Ken says, I am saying that it's a category mistake to apply the term "invalid" to inductive arguments, for inductive arguments are neither valid nor invalid--only not valid.

Recall the case with "not true" and "false"? False implies not true, but not true doesn't imply false. Same with not valid and invalid. Invalid implies not valid, but not valid doesn't imply invalid. Confusing not valid with invalid is like confusing not true with false.

---------- Post added 01-17-2010 at 10:59 AM ----------

[QUOTE=Emil;120455]

Validity theory
A first simple formulation of the central theses is:
An argument is deductive iff it is valid.
An argument is inductive iff it is invalid

[/quote]
An argument is either deductive or inductive. If an argument is deductive, then it's either valid or invalid. If it's invalid, it's not valid. If an argument is inductive, then it's neither valid nor invalid. If it's inductive, then it's not valid.
 
Emil
 
Reply Sun 17 Jan, 2010 09:59 am
@fast,
fast;120654 wrote:
To say of an argument that it's invalid implies that the argument is deductive. To say of an argument that it's not valid implies no such thing.

And yes, as Ken says, I am saying that it's a category mistake to apply the term "invalid" to inductive arguments, for inductive arguments are neither valid nor invalid--only not valid.

Recall the case with "not true" and "false"? False implies not true, but not true doesn't imply false. Same with not valid and invalid. Invalid implies not valid, but not valid doesn't imply invalid. Confusing not valid with invalid is like confusing not true with false.


Everything substantial you wrote here is false, but alas also irrelevant for this thread. If I have the patience I may explain it to you in another thread or over PM. And yes, I am very confident in my views about these matters.

For the sake of discussion. The terms "invalid", "valid", "not valid" means what I stated/stipulated they mean, not what you imagine they mean.

Do you have anything relevant to say? Like, about which theory of deductive and inductive arguments is true? Or some criticism of one of the two theories that I discussed above?

(My arrogance is partly explained by the number of irrelevant and derailing posts in this thread and the stupidity of what you write. I'm not claiming you are stupid, but that you say stupid things from time to time.)
 
kennethamy
 
Reply Sun 17 Jan, 2010 10:13 am
@Emil,
Emil;120599 wrote:
Because according to the intention theory iff the arguer intended an argument to be inductive, then it is inductive. And some arguers intend that a valid argument is inductive. Thus, there is a valid inductive argument.



The intention theory does not say that only if an argument is intended to be inductive, is it inductive. The intention is a sufficient condition, not a necessary condition. It is not a bi-conditional.
 
Emil
 
Reply Sun 17 Jan, 2010 11:19 am
@kennethamy,
kennethamy;120663 wrote:
The intention theory does not say that only if an argument is intended to be inductive, is it inductive. The intention is a sufficient condition, not a necessary condition. It is not a bi-conditional.


You may want to read my essay again for I clearly stated it was a bi-conditional. All explanations of what X is use a bi-conditional.

You are confusing using the arguer's intention as a means of discovering what type of argument it is, that is, purely as a method, with using the arguer's intentions to explain what type of argument it is. I pointed this out before but you must have missed it or ignored it.
 
Emil
 
Reply Mon 18 Jan, 2010 04:23 am
@Emil,
Emil;120673 wrote:
You may want to read my essay again for I clearly stated it was a bi-conditional. All explanations of what X is use a bi-conditional.

You are confusing using the arguer's intention as a means of discovering what type of argument it is, that is, purely as a method, with using the arguer's intentions to explain what type of argument it is. I pointed this out before but you must have missed it or ignored it.


Let me add, that the names of these two theories are, AFIAK, my invention and no one, AFAIK, besides us here talks about them. The IEP article, the only academic resource I could find on this, does not mention two theories but it endorses the intention theory of deductive and inductive arguments. At least it does not seem to me that the article is simply 'advocating' using arguer intentions as a method of discover what kind of argument it is.
 
fast
 
Reply Mon 18 Jan, 2010 10:17 am
@Emil,
What is the basis for thinking that the intention theory is true? It seems obvious to me that it's false because it confuses intentions with actuality. I may intend to give (for example) a conclusive argument, yet I may fail to actually do what I intend. If I give a non-conclusive argument, then I did not give a conclusive argument, regardless of what I intended to do.
 
Emil
 
Reply Mon 18 Jan, 2010 11:08 am
@fast,
fast;120801 wrote:
What is the basis for thinking that the intention theory is true? It seems obvious to me that it's false because it confuses intentions with actuality. I may intend to give (for example) a conclusive argument, yet I may fail to actually do what I intend. If I give a non-conclusive argument, then I did not give a conclusive argument, regardless of what I intended to do.


What does "conclusive argument" mean?

If you mean deductive argument, then you are begging the question.
If you mean sound argument, then it is irrelevant for the intention theory. Maybe you mean something else...(?)
 
fast
 
Reply Mon 18 Jan, 2010 12:08 pm
@Emil,
All women are mortal. Socrates is a man; therefore, Socrates is mortal.

Notice that I am not merely trying to provide support for my conclusion. I am trying to provide support so strong that the conclusion is guaranteed; hence, I'm not trying to say it's probable that the conclusion is true but conclusively true.

However, notice that I did not do as I intended. The form is not valid, yet it's a deductive argument, so it's an invalid deductive argument.

However, you say there is no such thing as an invalid deductive argument and that if an argument isn't deductive, then it's inductive, so according to your theory, the argument is an inductive argument.

However, it's not the case that I am merely trying to provide support but rather support so strong that the conclusion is guaranteed.

The intention theory nor the validity theory holds up.
 
Emil
 
Reply Mon 18 Jan, 2010 01:00 pm
@fast,
fast;120830 wrote:
All women are mortal. Socrates is a man; therefore, Socrates is mortal.

Notice that I am not merely trying to provide support for my conclusion. I am trying to provide support so strong that the conclusion is guaranteed; hence, I'm not trying to say it's probable that the conclusion is true but conclusively true.

However, notice that I did not do as I intended. The form is not valid, yet it's a deductive argument, so it's an invalid deductive argument.

However, you say there is no such thing as an invalid deductive argument and that if an argument isn't deductive, then it's inductive, so according to your theory, the argument is an inductive argument.

However, it's not the case that I am merely trying to provide support but rather support so strong that the conclusion is guaranteed.

The intention theory nor the validity theory holds up.


You should perhaps re-read my essay as you have completely confused matters.

So, since you have completely confused yourself and the matters in your post, you have given no reason to believe anything you claimed. Curiously enough everything you wrote is consistent with the intention theory.

At last, though, you have my thanks for attempting to take part in the discussion although this post fails completely, it is not irrelevant like some of your former posts in this thread. Smile
 
fast
 
Reply Mon 18 Jan, 2010 02:10 pm
@Emil,
Emil;120455 wrote:

Intention theory
A first simple formulation of the central theses is:
An argument is deductive iff it is intended by the arguer to be deductive.
An argument is inductive iff it is intended by the arguer to be inductive.


One need only briefly consider the implications of this flaky theory to realize that it's flawed. Maybe we should call this the Humpty Dumpty Theory of Arguments since it so closely resembles the flaky theory that words mean only what people say they mean.

A deductive argument is a deductive argument independent of what an arguer intends; furthermore, an inductive argument is an inductive argument independent of what an arguer intends. Yes, we cannot sometimes tell whether an argument is deductive or inductive if not privy to the arguer's intentions, but that is another matter entirely-truth is independent of knowledge ya know. Of course, I don't expect you to take my word for it quite yet, as I am merely denying that what you say is true and setting you straight on what is true.

Of course, I can do a little bit more than that. I can also help you get a handle on your mistake by encouraging you to use a little bit of reasoning as you explain to me why a sensible person would even think that what you say is true. But, what I don't need are links. I don't need inept sources, and I don't need to wade through your essays that are mistake-ridden-what is a sound inductive argument anyway?

What you need to do is step up to the plate and, in your own words, concisely explain why you think a kind of argument (deductive or inductive) is dependent on the intentions of the arguer. I have already pointed out the confusion upon which this flakiness is based. The theory (if we can call it that) confuses intentions with actuality. Sometimes, we don't actually wind up with what we intend on winding up with, and it's this very simplistic notion that is at the heart of my objection.

By the way, there's a difference between "arrogance" and "conceitedness." You may not care about others, but your condescending attitude is unwelcome, and it's far more inappropriate than any occasional thread derailment.
 
Emil
 
Reply Mon 18 Jan, 2010 03:44 pm
@fast,
fast;120856 wrote:
One need only briefly consider the implications of this flaky theory to realize that it's flawed. Maybe we should call this the Humpty Dumpty Theory of Arguments since it so closely resembles the flaky theory that words mean only what people say they mean.

A deductive argument is a deductive argument independent of what an arguer intends; furthermore, an inductive argument is an inductive argument independent of what an arguer intends. Yes, we cannot sometimes tell whether an argument is deductive or inductive if not privy to the arguer's intentions, but that is another matter entirely-truth is independent of knowledge ya know. Of course, I don't expect you to take my word for it quite yet, as I am merely denying that what you say is true and setting you straight on what is true.


But then again I am not endorsing the intention theory. You keep writing as if I did. It is annoying.

Anyway, all of the above is question begging against someone who holds that theory.

I don't think you have the authority to set anyone straight about this matter. Neither do I of course, but I have not claimed so.

fast;120856 wrote:
Of course, I can do a little bit more than that. I can also help you get a handle on your mistake by encouraging you to use a little bit of reasoning as you explain to me why a sensible person would even think that what you say is true. But, what I don't need are links. I don't need inept sources, and I don't need to wade through your essays that are mistake-ridden-what is a sound inductive argument anyway?


What does "what you say" refer to? I cannot tell. IEP is not an inept source. What kind of rubbish claim is that? The IEP article is pretty clear in its endorsement of the intention theory.

fast;120856 wrote:
What you need to do is step up to the plate and, in your own words, concisely explain why you think a kind of argument (deductive or inductive) is dependent on the intentions of the arguer. I have already pointed out the confusion upon which this flakiness is based. The theory (if we can call it that) confuses intentions with actuality. Sometimes, we don't actually wind up with what we intend on winding up with, and it's this very simplistic notion that is at the heart of my objection.


Again. I have not claimed that the intention theory is true, so this is another weird thing to be asking of me. It is as if you did not read what I wrote in this thread at all, including my essay. Please do so and then return.

Quote:
By the way, there's a difference between "arrogance" and "conceitedness." You may not care about others, but your condescending attitude is unwelcome, and it's far more inappropriate than any occasional thread derailment.


Maybe you think so. But you keep writing stupid irrelevancies like that not true does not imply false or was it not false does not imply true. Of course they do (in classical logic).

Your post contained no arguments (though some claims) relevant to the discussion of deductive vs. inductive arguments.
 
 

 
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