mnkbdky

Here is the argument, tell me what fallacy occurs:

It is true that

(A) either

(1) it is true that it is evil to torture infants for pleasure

or

(2) it is false that it is evil to torture infants for pleasure.

Now, (A) is only true if one of its components (i.e., (1) or (2)) is true or false.

It might be claimed, though, that there is another option

(3) since good and evil do not exist (i) and (ii) are neither true nor false.

However, this objection will not work. For if (3) is true, then, (2) is true also.

That is, if it is the case that it is neither good nor evil to torture infants for pleasure, then, it is false that it is evil to torture infants for pleasure.

So the claim that (1) and (2) are neither true nor false is itself false, since it verifies the truth of (2).

Therefore, if (2) and (3) are false, then, (1) must be true.

Therefore, it is true that it is evil to torture infants for pleasure.

semiotician

I don't know if this is what you meant, but if you swapped the word "good" for "evil" then you would reverse the arguement.

Prooving nothing by the argument.

mnkbdky

Good, but there is something more. Something that makes the conclusion in either case wrong.

Defiant Heretic

Well, for starters, you assume that it must be good or evil in all cases. It's possible that it could be good in some cases and false in others. (Note: I am not actually advocating this. I am stating the problem with the general form.) Bifurcation/False dichotomy, I would think.

Second:
You never demonstrate that one is false, which you need to do before you can proceed to the conclusion that two is true. I guess that'd make it a non-sequitor, although there might be a term for it in formal syllogistic logic.

philechat

It is a non-sequitur. We must ask the reasons behind the statement before it can be meaningful in any sense.

If the hidden statement is "the infants will suffer if we tortured them, therefore it is wrong to torture infants," it will be a terrible example of a non-sequitur using formal logic. The descriptive statement ("that the infants suffer when we torture them") does not imply any perscriptive statement (that it is wrong to do so).

It does not mean the statement is false in a societal (intersubjective) context however.

Clutch

On a quick read, I'd call it either a scope ambiguity with negation, or a false dichotomy, depending on where in the carpet one cares to make the wrinkle pop up.

not-(x is evil) /= x is not-evil, if 'not-evil' =df good.

Scorpion

How about blatant contradiction?

(this has an unsupported and also partly unnecessary assertion "good or evil do not exist" BTW)

The latter, when opened up, reads

"If it is true that since good or evil do not exist (1) and (2) are neither true or false, then, (2) is true also"



There is something profoundly suspicious in the introduction of (3) though (even if the unsupported and pointless assertions were removed or reconstructed) since it is a metalogical statement, i.e. a statement about the validity of other statements. In short, it says that (1) and (2) are meaningless. Now I'm not sure if there are modal logics in where this kind of stuff could be basically managed but I'm pretty certain that if there is statement A that declares some other statement B meaningless you can't deduce anything meaningful using both A and B in any system that makes any sense...

-S-

Clutch

Hey Scorp, I'm not terribly good at plumbing the heights of mnk's posts, but I thought the contradiction was the point.

Viz, that if you accept (A), presumably on account of it's looking like an instance of LEM, but hold that there is no such thing as good or evil, you somehow end up committed to (1).

The fallacy ends up being like this one:

It is not the case that the Moon is true;
therefore,
the Moon is not-true;
therefore
the Moon is false.

Of course, this is a fallacy -- take your pick which. If we lay it down that 'not-true' = 'false', we will deny the equivalence of 'not-(F is G)' with 'F is not-G'. Or, if we are committed to that equivalence, we will regard 'not-true' = 'false' as a false dichotomy; the Moon is an obvious counterexample.

Jamie_L

This arguement is muddled all over the place. Let's clean it up:

Let's start with the basic proposition(P):

P: Torturing children is evil.

Next we have:

(A): Either P or Not P

Note that this is essentially a tautology. (A) must be true unless P is both true and false or neither true nor false. (3) asserts one of these illogical possibilities:

(3): Neither P nor Not P

We rightly say that (3) is false, because P cannot be neither true nor false. Just as it cannot be both true and false. This has nothing to do with good or evil, it's just a fact that the Proposition P is a statement of truth, and thus has only two possible truth values: true or false. Both and neither are not possible truth values.

So, we deny (3) and confirm that (A) is true by virtue of its logical form alone. The arguement then goes awry:

Not (3), therefore P.

This is the logical error.

This is actually an error of Missing the Point, specifically an Irrelevant Conclusion. Not (3) proves that (A) is true, but the arguement claims Not (3) proves that (P) is true.

All this, of course, coming from a yokel with no logic training. But, that's the way I see it.

Jamie

Scorpion

Dammit, you beat me to it

I just started to reconstruct the argument myself since I wasn't quite happy with the way I went at it in the first go, but you saved me the trouble, Jamie_L

-S-