Logical Relativism

[Lord MJ]

We all know about moral relativism and the evils associated with it. It's been discussed at length.

But what kind words do you have to say about logical relativism. Basically saying there is no such thing as objective logic and everything is subjective.

I mean how can you respond to someone in a debate that says something like this:

In your logical system Appeal to Authority/Slippery Slope/Appeal to Popularity is a fallacious argument, but in MY system of logic, those arguments all all perfectly valid!![/quote]

[Kuroneko]

One way would be to require systems of logic to try to evaluate them in a manner analogous to that of scientific theories--for example, how well a logic system models reality when experience is formulated in that system's terms. Of course, as a purely practical matter, there is little use in arguing with someone who makes such an argument seriously. Such an opponent might then make the argument that one needs some sort of logic to start with in order to evaluate systems in this manner. This is true, but the alternative is perfectly useless.

[Lord MJ]

I've found that many people construct their "logical system" in a way so that their personal beliefs on issues are valid in said system.

So if they have a position that is illogical due to the slippery slope fallacy for example. There logical system will be one that the slippery slope is a correct logical argument so they will be able to rebuff such attacks on their position.

In some cases their logical system is dynamic in that it changes to support whatever beliefs they hold. So someone that believes the slippery slope is a fallacy will change their logical system so that is not a fallacy if an argument they agree with doesn't hold if the slippery slope is a fallacy.

[Eris]

While Kuroneko is correct in his assessment, I would elaborate on a few points. Firstly, we do need a logical framework of sorts to work within to define our logical system, however it's not as much a vicious circle as it sounds. Formal induction (that is, prove it for the base case and for all functions defined for the structure) and definition by recursion are the sorts of things that are the answers to exactly that kind of problem.

Two further rebuttals come to mind. One is that logic as we have it formulated always works. So long as you have a domain of things being talked about, logic will preserve truth (or rather, satisfaction under an assignment, but it works out to be the same thing for practical purposes) from one sentence to the next. That's all it's supposed to do, and there not only are any counterexamples, but there can't be any. Any other "logical" systems that produce different results are simply wrong.

Which leads to the second rebuttal. When someone starts talking about other systems of logic, ask them to provide their axioms, and the theorems they're using when they make these interesting inferences. I can assure you with near certainty that they won't have a clue what they're doing. You see, logic is designed so it works for any arbitrary structure, domain, assignment, etcetera. Logic can't go wrong because we made it so it can't. Anyone who tries to invent their own generally doesn't realise this, and consequently run into problems because their "logic" is tailored for certain domains, or situations, or whatnot, and fail given an arbitrary set of parameters.

Ultimately, for I can give a sketchy babble of an explanation of why logical relativism is a retarded idea, Kuroneko I think put it best. You simply can't argue with people who seriously believe in other logics than the one we have. They clearly haven't the foggiest idea about what they're talking about.

[Spyder]

We all know about moral relativism and the evils associated with it. It's been discussed at length.

But what kind words do you have to say about logical relativism. Basically saying there is no such thing as objective logic and everything is subjective.

I mean how can you respond to someone in a debate that says something like this:

In your logical system Appeal to Authority/Slippery Slope/Appeal to Popularity is a fallacious argument, but in MY system of logic, those arguments all all perfectly valid!!

That's basically what you get when post modernists try and apply their bullshit to hard sciences. It's more then a little sad. The only real response is

"You can't have different systems of logic, it would be like having different systems of that rock over there, I know you can't understand this analogy because quite frankly, you're too stupid to understand how objectivism works, And for the love of Allah do NOT attempt to go into further detail about your "system of logic" because it's just going to be waffly gibberish that I'm sure you find impressive but really just makes you sound like an arse. Fuck you for trying to infect me with your brain poison!"

[Kuroneko]

Alternative logic systems may deserve consideration, but not in the sense that this 'logical relativist' in proposing. For example, certain situations in quantum mechanics can be modeled directly in a logic system without the distributive law, while our normal logic requires a bit more conceptual machinery to deal with them. At least in principle, a person could adopt such a system as their 'general logic' and supplement it with some extra framework should the situation require for it, just as we invent a theory conforming to our logic whenever we encounter new phenomena.

In other words, for an alternative system to be taken seriously, a proponent of it should provide some evidence that it works efficiently in generating true conclusions, which in turn should not be different from the normal ones in domains they are known to be correct. That's clearly not the situation with the logical relativist, however. (Working at all is not a real issue, since just about anything can be made to "work" if one is willing to go through enough mental contortions to artificially preserve its claims, especially if we're considering modifying logic itself. Ockham's razor holds in the sense that such contortions are undesirable and should be minimized--which can be said to be a measure of efficiency for a logic system.)

[Junghalli]

The great rebuttal to relativism is pragmatism. The reason we call scientific findings objectively true is that they work: they allow us to make reliable predictions about how the universe works and what will happen if we do certain things or don't do certain things. Defeat people who play the relativism card by pointing out that the logical system you are using works better than the one they want to use in dealing with real life.

[Darth Servo]

How can you have relativism in a system that has well defined rules? Its like proposing about "mathematical relativism." "2 + 2 = 4 in YOUR system but it equals 5 in MY system."

The way one would attack the rules of logic would be showing that those rules don't work and after centuries of examining them, good luck.