# Is Logic Reliable?

After re-reading Quine’s “Two Dogmas of Empircism,” I began to think about the analytic/synthetic distinction and the effects rejecting this distinction could have on science and logic. Papers and books have been written about the reliability of Science and the issues of using science to prove science’s reliability (See Popper). However, if the distinction is not real, wouldn’t it prove that logic also may not be reliable? If logical truths, mathematical truths and the like, really are no different from other empirical observations- wouldn’t they also be suspect? I am not saying we should do away with logic- like science, it’s practical and useful. But should we use logic with the understanding that it too may be faulty or incomplete? Also, I have heard that there are new science experiments that show reason to question identity itself (eg. x=x may be false).

thoughts?

when logic becomes unreliable it ceases to be logic.

logic could be said to be an understanding. understandings are dependent on perspective, and perspectives change.

Logic (in the sense of logical evaluation) is relative and thus limited.

It’s reliable if we have reliable focus on the matter to be evaluated and if we apply reliable evaluation method.
As the reliability of the focus and the evaluation method is a relative matter with certain conditions/limitation, resulting evaluation is also only valid and reliable within certain conditions/limitations/perimeter.

Often, people aren’t aware of the focus nor the evaluation method, making their statements and thoughts very unreliable.

Logical truths are such because they are self referential. If you quantify a proposition, then you’re already stipulated that you’re ingoring certain distinctions that might cause contradictions when applying this quantification to physical things. So while logic might not always fit exactly into what we see,(but I think it does), the form itself is reliable in that it’s self referentially true.

I think you’ve got it right, Smears. So few do.

Logic is never directly applied to the world we experience, but only to statements we make about that world. Those statements are thought to be accurate. They may or may not be. If they are not, then logic may be of no practical use. Of course, any method of analysis could produce a practically useful answer, even if that method is flawed, which is how I scored a 670 on my math SAT’s, even though I could not do the math in most cases.

This is a point I was making in my post about measuring the world, IIRC. Every time we generalise, we do this. The more we generalise, the further away we get from reality, because we get further from particulars. Logic does not reverse this process, it abets it.

I love particulars. My gut tells me they’re the only things that are “real-real” but I have so much fun with universals, that I just, I just don’t know how to say it.

should we be justified in using self referential truths? considering the identity experiment- we may not be justified in saying something as simple as x=x- even though it is self referential. obviously it’s practical and useful- as is science. my argument is that without empirical data- we wouldn’t have any self referential truths. So, if empirical data in incomplete or insufficient to make these claims, should we quantify such propositions? like i said earlier, i think we should, but we do so understanding that these are based on unproven theories.

x=x can’t be false because it doesn’ convey anything more than ‘x’.

1. London

Is 1) true or false?

Quine’s rejection of the analytic/synthetic distinction relies on the notion that analytcity, a-priority and necessity are all interdependable, but most agree now that this isn’t he case. Soame’s anaylis is probably the best, or else Kripke’s ‘naming and neccessity’ in which the distinctions are made (it’s the final section of the paper, about belief holism, that really set the philosophy world alight).

Smears - Maybe someone will do a musical comedy about universals some day.

rs -

That’s incorrect. x = x does not require empirical data. No empirical data would actually make “x = x” useful. Empirical data in fact shows that x = x is not true, in the real world. In the time it takes to say “x = x”, x has changed. Only when we abstract an identity do we have an identity. The rule x = x is used in mathematics and logic, which is, in turn, applied to the real world.

Such axioms not based on unproven theories. They are merely accepted. They are neither proven nor provable. And there is no theory behind them. They are the parameters of logic. They are what we accept when we embark upon a logical argument. This has often been used as an excuse for skepticism, nihilism, solipsism, and bad personal grooming by the uninformed. It is none of those things.

The difference may seem insignificant. I often sense that people think I am merely being pedantic in saying these things. But the terminology of logic and science are so easily confounded that it does, in fact, make a difference.

Fortunately, this kind of thing makes most people’s eyes glaze over, so it is of little consequence. Unfortunately, if you don’t understand this, you have no hope of understanding logic.

So basically, the conclusion is only as true as the premises, and the premises themselves cannot be reduced to simple enough terms that they correspond directly to “truths” in the real world. All premises, no matter how clear and obvious they seem, are themselves but shaky assumptions that entail even more shaky assumptions, all made by sloppy observers. Logic is just symbol shunting, the symbols themselves cannot correspond 1 to 1 to objects in a world of infinite, fractal details.

the problem with logic is that , it doesn’t invite an increase in knowledge

logic dwells upon the knowledge given only

I don’t think this is true. To steal an example, if you know that North is the person whose post you read last night, and you also know that the person beside you in the checkout line at the grocery store is North, then isn’t the realization that “the person whose post I read last night is standing beside me”, given by the simple logic that a=b=c therefore a=c, new knowledge?

Only if you weren’t really paying attention.

nice one.

also a good point to keep in mind.

and as you said, if only those who are unable to understand this subtle distinction would remain ignorant of their inabilities, instead of further confounding their own (and other’s) confusions…

Do you know, before you do the multiplication, that, 989 X 628 = (whatever it is)? If not, then after you have done the multiplication, you had an increase of knowledge.

Changed to what? To y? Or to another x? If so, x is still x.

But if it changes to another X, it is not the same X. But X=X only means that X=X at the moment it is said. So whether X changes is irrelevant, since when it changes, it remains the same X. X always is equal to X at the particular moment. It has nothing to do with how long it take to say it, for the truth of X=X does not depend on anyone saying that X=X, anymore than the truth of, “the Earth is round” depends on my saying that the Earth is round.

Jake - it’s still x if we’re still calling it x. The white dwarf is the red giant and the red giant is the white dwarf. And it’s everything in between. Are white dwarfs equal to red giants? They are if we say they are, i guess.

Kenny -

What is a moment? Do moments exist? How long do they last? Moments are okay - they just don’t exist in the real world.

Well, that was your argument, not mine. You were the one who said that in the time (the moment) it took to say X=X, X will have changed. I didn’t.

I meant an interval of time. A moment is not that.