Also, you did not answer the question. Again!

I shouldn't have said, "can't." I should have said, "cannot." "Can't" is a contraction of "can" and "not", but that's not what I meant, as I didn't mean, "can not." I meant, "cannot." So, change that to "cannot possibly."

If I'm onshore, I can go to the grocery store, or I can choose to not go (hence, I can not go; moreover, to not go is a course of action I can choose) to the grocery store, but if I'm out to sea, I cannot go to the store; hence, it's false that I can go, and it's false that I can not go. How is the second false? That I can not go implies that I could, but I couldn't, and if I couldn't (which is true), then it's neither that I can or can not, yet it's still true that I cannot. Thus, there is a distinction between "can not" and "cannot."

By the way, I'm not so sure the definition of "valid" as conveyed by you means what you think it does. In fact, I think it supports what I'm saying--not what you're saying.

It does not follow that there is a distinction between "can not" and "cannot" in general and in other contexts because you found a way to express something where it makes a difference between which you use. What you're talking about above is what I call willful possibility. But your way of talking about it is extremely bad. I rather say that "it is willfully possible for you to go to the grocery store", and "it is willfully possibility for you not to go to the grocery store". No need to use bad, and odd, sentences such as "I can not go" to mean anything else than what "cannot go" means.

I've never heard anyone make this distinction, "can not" means the same thing as "cannot", as far as I'm concerned. This kind of pseudo-pedantry is quite irritating as the desired distinction is very easy to make with "possible to. . . . " and "possible to refrain from. . . ." and "not possible to. . . . or refrain from. . . ."

PS. You still have not answered what you mean when you write "invalid". For me it is quite simple. I just mean non-valid, an argument that is not valid.

When I say that an argument is invalid, I mean that it's possibly valid yet not valid. When I say that an argument is not valid, I mean just that--that it's not valid.

Hope that helps.

"I can go, or I can not go." is neither a bad nor odd sentence, and the difference between what "can not" and "cannot" means has nothing to do with me.

If it's true that you cannot go, then technically, it's false that you can not go. Besides, how can you blast me for this, especially considering you asked me what I meant?

Ughaibu,

What is pseudo about it, and what difference does it make that you never heard anyone make this distinction? I think it was covered in either the 4th or 5th grade.

Correct.

Does it help if I told you that inductive arguments cannot be valid?

No it's not. The contraction of "can" and "not" is "can't."

I'm still a bit weak when it comes to differentiating between the different kinds of possibilities. I'm fearful that if I throw out an adjective that I may be mistaken, so it's not so much that I don't know what I have in mind than it is that I'm just not sure which word(s) to use to articulate what I mean.

Epistemic possibility comes to mind, but then again, maybe to say logical possibility is more appropriate. I'm just not sure what word to use really.

An inductive argument can no more be invalid than can a rock be dead.

I'm still a bit weak when it comes to differentiating between the different kinds of possibilities. I'm fearful that if I throw out an adjective that I may be mistaken, so it's not so much that I don't know what I have in mind than it is that I'm just not sure which word(s) to use to articulate what I mean.

Epistemic possibility comes to mind, but then again, maybe to say logical possibility is more appropriate. I'm just not sure what word to use really.

An inductive argument can no more be invalid than can a rock be dead.

If someone were to say that it is possible that argument A is valid, I would suppose he was telling me that he did not know whether or not A was valid, but he rather doubted it. If someone were to say to me that A's validity is possible, I would take him as saying that the proposition that A is valid is not self-contradictory. In the first case, the person would be talking about epistemic possibility. In the second, logical possibility. Of course, in either case, it is implied that to say of A that it is valid (or invalid) is not a category mistake. So, it seems to me the question is whether to say that A is invalid where A is an inductive argument, is a category mistake or not. It seems to me that saying of an inductive argument that it is invalid or valid is like saying of it that it is true or false. A category mistake.

Having said that, I must add that some eminent philosophers have not believed in category mistakes on the grounds that there are no truth gaps. Quine for example. So this issue is discussable, to say the least.

Note that whether an argument is valid or invalid (non-valid, not valid) is a necessary truth. So if one says that it is logically possibly valid, that implies that it is valid. So it is not a weak modal claim as one might think in this relation.

In any case, none of you two has ever offered, to my memory, an argument that "invalid argument" is a category error like "true argument" is. Even though it has been so long! I'm beginning to think that you don't have one, the other possibility being that you don't want to tell me about it.

We did not say that "invalid argument" is a category mistake. We said that "valid inductive argument" is a category mistake. The argument for that is that since inductive arguments cannot be valid, they cannot be invalid.

I thought it was contingent upon whether the conclusion can and does follow from the premises. If it can and does, then it's valid, and if it can and doesn't, then it's invalid. Never can the conclusion of an inductive argument be entailed by its premises, so no inductive argument is invalid.

I forgot a word. I meant "valid inductive argument". Your argument's conclusion has nothing to do with the claim at hand.

I forgot a word. I meant "valid inductive argument". Your argument's conclusion has nothing to do with the claim at hand.

---------- Post added 04-15-2010 at 04:12 PM ----------



I don't know what you are talking about.

Whether an argument is valid or not, is a matter of necessity, something to do with relation of ideas (Hume's Fork), not matters of fact. It is not a contingent matter.[INDENT]1. If the moon is spherical, then the earth is spherical.
2. The moon is spherical.
Thus, 3. The earth is spherical.
[/INDENT]That argument is valid in all possible worlds. It is not invalid in any possible world. That argument is sound in some possible worlds (like the actual world), and unsound in others.

Why is that? Analogy: Arguments cannot be false, therefore, they cannot be true. Is the above argument irrelevant to the view that "true argument" is a category mistake?

I think that fast may mean that whether some deductive argument is valid or is not valid is not a necessary truth. A deductive argument can be either valid or not valid. Of course, if an argument is valid (or invalid) the argument is necessarily valid (invalid).

I don't agree that an argument cannot be true, or be false. Unless you mean semantic 'possibility', and if you do, you should be more clear and avoid ambiguous sentences. It think it is a category error/mistake to say that "That argument is true". I do not think it is a category error to say that "That inductive argument is valid". If the latter is what you mean, you better produce an argument with that as the conclusion. None have been provided so far. If you mean something else, please say so. I cannot read minds. On the other hand, it is, of course true, that inductive arguments are not valid. To say that all inductive arguments are invalid is to imply that all inductive arguments fail in some way. To say that No inductive argument are valid is only to point out and inductive and deductive arguments are very different kinds of reasoning.

I don't see what the analogy is supposed to be between "invalid inductive argument" and "true argument", unless the analogy is that they are both category mistakes. If that is so, then it is a question begging analogy.

Logical Fallacy: Question-Begging Analogy

---------- Post added 04-15-2010 at 10:17 AM ----------





I don't understand what you think that Fast may mean.

The argument is that since to call all inductive arguments invalid would be to say that it is possible for any inductive argument to have true premises and a false conclusion, and since that the definition of an inductive argument, what you seem to be saying is that no inductive arguments are deductively valid. And that, of course is true. But when we say of a deductive argument that it is invalid, we are saying that it commits a fallacy. Do all inductive arguments commit fallacies just in virtue of their being inductive and not deductive? Are all inductive arguments fallacious? That is what saying that all of them are invalid implies.

I think you ought to reread what I wrote that fast means. It is true, is it not, that (A) whether a particular argument is valid or not is a contingent matter? But that (B) if an argument is valid, then the argument is necessarily valid. Isn't that true too? And that (A) and (B) are consistent? Well, that is what (I think) fast meant.

Thank you for the link. Clearly, to suppose that the analogy made in your question is a correct analogy is to beg the question. For example, one poster on a different thread argued that fate and free will were compatible in the way that wave and particle theory were compatible. I pointed out that begged the question, since it is by no means clear that there is an analogy between QM and the issue of free will versus fate. I think that is what you mean. Obviously I believe that the analogy between the notion that arguments are true or false, and inductive arguments are valid or invalid, is correct. Otherwise I would not have employed the analogy. And, if I am right, then I have not begged the question.