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.
That is like saying, to someone who says that all bachelors are unmarried, that that person is begging the question about what the term "bachelor" means.
If two people were discussing what "bachelor" means and one of them said that, then yes, he would be begging the question.
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 ----------
Where can I read about that theory? It was not mentioned in the IEP article. The IEP article clearly presumes the intention theory.
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.
I think you have misunderstood the IEP article
. I do not think that the author seriously endorses what you are calling the "intention theory". I believe that he or she is attempting to give a practical way of figuring out what argument it is that is being discussed. When someone presents an argument, you first need to understand what they are talking about so that you can know what argument it is that is to be evaluated. It is only after you know what the argument is that you will be in a position to know whether it is valid or invalid, sound or unsound, etc.
I think that is possible, but consider this quote from the IEP article:
[INDENT]"A deductive argument
is an argument
in which it is thought that the premises provide a guarantee
of the truth of the conclusion. In a deductive argument, the premises are intended to provide support for the conclusion that is so strong that, if the premises are true, it would be impossible
for the conclusion to be false.
An inductive argument
is an argument in which it is thought that the premises provide reasons supporting the probable
truth of the conclusion. In an inductive argument, the premises are intended only to be so strong that, if they are true, then it is unlikely
that the conclusion is false.
The difference between the two comes from the sort of relation
the author or expositor of the argument takes there to be between the premises and the conclusion. If the author of the argument believes that the truth of the premisesdefinitely establishes
the truth of the conclusion due to definition, logical entailment or mathematical necessity, then the argument is deductive
. If the author of the argument does not think that the truth of the premises definitely establishes the truth of the conclusion, but nonetheless believes that their truth provides good reason to believe the conclusion true, then the argument is inductive
[/INDENT]Any straightforward reading of that results in one thinking that it endorses the intention theory. It uses almost the exact same phrases as does the intention theory (more specifically, my formulation of it). Compare:[INDENT]"A deductive argument
is an argument
in which it is thought
that the premises provide a guarantee
of the truth of the conclusion. In a deductive argument, the premises are intended
to provide support for the conclusion that is so strong that, if the premises are true, it would be impossible
for the conclusion to be false." (first three paragraphs in IEP article) [my bolds]
"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." (from my essay draft above) [my bolds here, not in original formulation]
[/INDENT]Though it is not of vital importance to the points that I make in my essay that the IEP article supports the intention theory.
As you already know, many people jump to wild conclusions about what argument someone is talking or writing about, and so they end up with useless discussions that are totally beside the point that the person is trying to make. So, from a practical standpoint, it is a good idea to emphasize the attempt at understanding intentions when dealing with arguments in the real world.
I agree with this. But that does not imply either of the two theories above and it is consistent with both.
If you wish to say that the person's remarks literally entail your "intention theory", then I will only say, if that is so, then the article is improperly written.
Why? Because it endorses a theory among many?
I do not believe you will find any credible source that explicitly endorses your "intention theory".
Maybe, maybe not. I haven't found any
credible source dedicated to this issue.
To go back to your article in post 68
, your "Validity theory", in which you state, "An argument is deductive iff it is valid.
An argument is inductive iff it is invalid."
That is also unsatisfactory, for the reasons you state. So, with both of the theories you have presented, you have given reasons to reject them. But neither theory is one that I have ever even heard of anyone endorsing.
Then you have not read the threads to which I linked in the beginning of this thread. There is a person on FRDB who seems to be a high quality poster that supports the validity theory. Though the name is my invention. I could have called it the formalist theory, but validity theory seems to capture the important point better, so I will stick with that. Also "formalist" has other connotations that I would like to avoid.
You seem to be wanting a definition of a deductive argument and an inductive argument, of the form, "an argument is ... if and only if....", such that everything is rigidly and absolutely determined. You do not always get what you want, and I will not give you any such definition now.
I would not call it a definition, but rather an analysis, akin to an analysis of the concept of knowledge.
A deductive argument is one which is valid or one which resembles a valid argument. Thus, the fallacy of affirming the consequent is a deductive argument, because it resembles the valid argument modus ponens. The fallacy of affirming the consequent is a deductive argument because it looks like such a thing. It appears as though the conclusion is supposed to necessarily follow from the premises, and so it is a deductive argument. An inductive argument is any argument that is not deductive. Or we could say, an inductive argument is one in which the premises appear to offer some sort of support for the conclusion that is less than conclusive. (Anything that does not offer or appear to offer any kind of support is not an argument.)
I find it odd that you go on to state what looks like
an analysis of the concept of deductive argument.
Also, your first analysis of inductive argument is a negative one, that is, it characterizes an inductive argument by a lack of certain properties. That is perhaps a good idea.
I like all your proposed analyses.
Wikipedia expresses it this way:[INDENT][INDENT]In logic, an argument is a set of one or more meaningful declarative sentences (or "propositions") known as the premises along with another meaningful declarative sentence (or "proposition") known as the conclusion. A deductive argument asserts that the truth of the conclusion is a logical consequence of the premises; an inductive argument asserts that the truth of the conclusion is supported by the premises.[/INDENT][/INDENT]
In this case it 'talks' about arguments asserting things, but arguments, I think, do no such thing. That is an anthropomorphism. Some humans use arguments to support their assertions.
But supposing that it is not an anthropomorphism. Then there is some property of arguments about how they assert their conclusion. That is odd but I wouldn't be totally dismissive of it, at least to begin with. If there is such a property then all definitions of "argument" that I have read are wrong since none of them mentioned that property but only something like "(philosophy, logic) A series
of statements organized
so that the final
statement is a conclusion
which is intended
to follow logically
from the preceding
statements, which function as premises
But I am not particularly unsatisfied with it.
In fact you gave some useful proposals for a correct analysis of deductive argument and of inductive argument. I will have to think more about them.
What are platonic essences, anyway?