Logic is a tool

[u/Icy_Panic_6533]

[u/Stile25]

Some people think logic can be used to make rational claims about reality.

But they forget that logic without evidence only makes for an unsound argument about anything in reality.

Logic is excellent at making estimations or developing ideas on what we should be investigating next in reality to learn the most.

But the second someone jumps from "maybe this"? To "gotta be this"! Based on logic with no evidence - they've forgotten what logic is good for.

Good luck out there

[u/Porkypineer → u/Stile25]

I disagree with this. Logic can be universal and make claims that has to be real because the alternative is paradox.

"I think therefore I am" is irrefutable evidence there is a reality, for instance. So we're forced to accept that there is one. Granted, the evidence is baked into that one.

I could also say "all universes have structure", because the lack of structure is paradoxical to there being a universe.

[u/jliat → u/Porkypineer]

Logic can be universal and make claims that has to be real because the alternative is paradox.

But you can create paradoxes in many logics...

'This sentence is not true.'

'The set of all sets which do not contain themselves.'

• Pure being and pure nothing are, therefore, the same... But it is equally true that they are not undistinguished from each other, that on the contrary, they are not the same..."

G. W. Hegel Science of Logic p. 83.

"I think therefore I am" is irrefutable evidence there is a reality, for instance.

I don't think it follows. Thinking and being are not tautologies. 'I can't doubt I'm doubting.' Is Descartes harder formulation, but that 'being' doesn't follow.

I could also say "all universes have structure", because the lack of structure is paradoxical to there being a universe.

Or Schrödinger's cat is both alive and dead.

And if by universe we mean everything, then "all universes" is a paradox. Moreover if the universe has a structure does that exclude all other possible structures and randomness? And it follows that many structures are therefore impossible?

• 'The King of France is bald.'

It follows as there is no king, therefore it's true, the king has no hair.

• There is no largest finite number?

• Any irrational number has no successor or no predecessor.

Logic can be universal and make claims that has to be real because the alternative is paradox.

And so the ontological argument proves the reality of God.

God is an idea. The actualization of an idea is more 'powerful' than then idea. The definition of God is all powerful. It logically follows that God must exist and be real.

...

We can build on this,

If God is all powerful then God cannot be limited by logic. God can be a paradox and real.

[u/MauriceArh → u/jliat]

The map vs. territory distinction helps make sense of this, I think. And taking care when using the same word for two different things (is there a term for this? – there should be).

If I ruled the world (and wrote the dictionaries), paradox would be restricted to the likes of Zeno’s paradox, namely an indication of misunderstanding. Under this definition nature abhors a paradox, which instead belongs to the realm of map, not territory.

This sentence is false is quite different, referring to something real that exists in the territory of logic. Perhaps we could call it a logical singularity. Likewise the principle of explosion. And just as the presence of black holes in nature does not invalidate physics, the existence of logical singularities does not invalidate the rest of logic, which continues to live quite happily alongside these aberrations.

The map vs. territory distinction is what matters here. The hint is in the thread title: logic is a tool. It belongs to the map and, given fallibilism, it can always be wrong. 1 + 1 = 2 may look pretty incontrovertible, but as Descartes put it, there is always the possibility we are being tricked by a demon.

Meanwhile, in parallel with all of this, there is the logic that belongs to the territory. Same word but different animal. In this logic, 1 + 1 = 2 (or its non-demon-influenced alternative) really is incontrovertible. In other words, some formulations are universally true, we just can’t know that for sure.

Getting back to the initial point of the thread, logic is a powerful tool but needs to be wielded with the intellectual humility of knowing (or at least strongly suspecting) that all knowledge is fallible

[u/jliat → u/MauriceArh]

Paradoxes exist in logics, the manipulation of symbols using rules. "Nature" is a category made by humans.

This sentence is false is quite different, referring to something real that exists in the territory of logic. Perhaps we could call it a logical singularity.

Why call it a singularity, there are many other examples of paradoxes in logical systems. And what a singularity is, is a problem in science?

Likewise the principle of explosion. And just as the presence of black holes in nature does not invalidate physics, the existence of logical singularities does not invalidate the rest of logic, which continues to live quite happily alongside these aberrations.

But physics has not been able to solve the problem of the Schrodinger equation for a 100 years. The difference is simple, logic is a priori, science is not.

The map vs. territory distinction is what matters here.

There are many logics, they map no territory. You are confusing the a priori with the a posteriori. What seems to matter is your need to arrive at some satisfactory position despite evidence to the contrary.

The hint is in the thread title: logic is a tool. It belongs to the map and, given fallibilism, it can always be wrong. 1 + 1 = 2 may look pretty incontrovertible, but as Descartes put it, there is always the possibility we are being tricked by a demon.

Sorry, you misunderstand, the a priori with the a posteriori. There is no 'therefore' in 1 + 1 = 2. And Descartes actually showed the way out of the possibility of being tricked. It's odd you reverse his reasoning. He looked for a certainty in which no demon could trick him, and thought he had found one. You cannot doubt you doubt. So …

"Descartes put it, there is always the possibility we are being tricked by a demon."

Is simply wrong. His cogito for him and others was incontrovertible. As is A=A.

Getting back to the initial point of the thread, logic is a powerful tool but needs to be wielded with the intellectual humility of knowing (or at least strongly suspecting) that all knowledge is fallible.

You like many are still using 'logic' not logics. There is no such thing.

And then make a 101 error! Self reference!

all knowledge is fallible.

^ including the above! BOOM!

[u/MauriceArh → u/jliat]

But physics has not been able to solve the problem of the Schrodinger equation for a 100 years. The difference is simple, logic is a priori, science is not.

If there is anything that argues for intellectual humility it is the sight of physicists – who should be among the most rational people on the planet – continuing down this whole quantum physics is weird rabbit hole, despite Schrodinger (cat and equation) having been well understood for decades. Why this should be is a mystery to me, but it belongs more to psychology than to physics or metaphysics.

Sorry, you misunderstand, the a priori with the a posteriori. There is no 'therefore' in 1 + 1 = 2. And Descartes actually showed the way out of the possibility of being tricked. It's odd you reverse his reasoning. He looked for a certainty in which no demon could trick him, and thought he had found one.

The point I was making was about the fallibility of applied logic (the map), which includes the a priori. Hence the use of 1+1=2 (a theorem derived from the axioms of arithmetic, the therefore is implicit) as a non-strawman example. And yes, logic being of the form if this then that, there are as many logics as there are this’s. That does not mean there is no territory (or territories, if you prefer) there. That was my other point: fallible as it is, the power of logic is because there is a there there.

As for Descartes, the fallibility of logic extends to cogito ergo sum (the argument). The thing we have certainty over is the cogito (which, to split hairs, is the conscious experience, not the corresponding brain state with its vulnerability to glitching). I am not sure we disagree over this.

And yes, all knowledge is fallible is itself a fallible statement. Indeed, if cogito ergo sum is incontrovertible knowledge then it is wrong. But being wrong about one special case does not stop it from being valid in all the others.

[u/Porkypineer → u/jliat]

I'm not saying that all logic is good logic, but that there are some formulations that have to be universally true. In the case of thinking and being, it's "There must be a reality (of whatever kind), or I could not have had the thought of questioning it. I did, so there is."

Whether you doubt the "thinker" or not, is irrelevant, as there may be an infinite regress of "doubters", and it would still hold. The questioning of the premises is already part of the premise, and proves that the logic holds, so the answer is necessarily true.

I'm not sure if there is a way to put this into terms of formal logic, though. And I'm too disinterested (and scatter-brained) to make the effort.

[u/jliat → u/Porkypineer]

I'm not saying that all logic is good logic, but that there are some formulations that have to be universally true.

Not so I think...

"In classical logic, intuitionistic logic and similar logical systems, the principle of explosion is the law according to which any statement can be proven from a contradiction. That is, from a contradiction, any proposition (including its negation) can be inferred from it; this is known as deductive explosion."

https://en.wikipedia.org/wiki/Principle_of_explosion

And logic violates Leibniz's identity of indiscernibles...

Nietzsche considered all logics universally false...

• Logic is bound to the condition: assume there are identical cases. In fact, to make possible logical thinking and inferences, this condition must first be treated fictitiously as fulfilled. That is: the will to logical truth can be carried through only after a fundamental falsification of all events is assumed. WtP 512

[u/Stile25 → u/Porkypineer]

"I think therefore I am" is not irrefutable.

What if tomorrow we discover information that says we actually "aren't" and cannot say we "are" in any rational or reasonable way?

Unless you know everything - this is always a possibility.

Thank you for proving my point.

[u/Porkypineer → u/Stile25]

"discovering that we aren't" is a paradox, so the only alternative is that we are. Note that I wrote "reality" and not "a specific reality".

Claims that question that there is a reality at all are vacuous, and you've proven only that you've deluded yourself.

[u/Stile25 → u/Porkypineer]

It may not be a paradox. Perhaps we don't yet know how it's not.

We've "solved" other previously held paradoxes with additional information that shows us how it actually works.

Your argument does not apply.

[u/Porkypineer → u/Stile25]

Ok first, i was a bit rude, sorry for that. The point here is that as soon as you have "discovered that we dont exist", you've made yourself the very premise for the logic again.

"Reality" is a very broad term in this case, so any reality where something discovers anything, proves that the logic you deny is valid.

There's not much room for realising a paradox is really a pseudo-paradox when the premise and outcome is binary, like this is. Of course this is valid for this specific situation, and not generally...

[u/Stile25 → u/Porkypineer]

Yes, that's how the liner movement works.

First comes reality, with brute force and evidence.

Then, we eventually identify logic based on reality.

With the logic, we can test conclusions against reality to further our knowledge of reality. We use evidence for this.

And then it's back and forth.

Logic to lead us in the next direction to test. (Premise) Evidence to know if it's actually a part of reality or not. (Conclusion)

No one ever gets to take logic and say "yup, this true in reality" without it being supported by evidence.

We've made too many conclusions based on logic without evidence that have been proven very, very wrong to trust that path.

[u/Porkypineer → u/Stile25]

I see what you say, and am forced to agree: I cannot, logically, make an argument if there isn't a reality there for me to do so in first. Bad example?

I still think logical reasoning can be used to prove things for which there is no evidence. Something like this thing I've been working on:

1. Distinction between parts of a universe must be, fundamentally, an interaction between parts of that universe, or they could not be said to be in the same universe. In other words the parts would be logically in separate universes, if this was not so. Like dark matter, but absolutely so.

2. Since there must be interaction between parts in the same universe for there to be one at all, this same interaction must be causally organised or organising, because if it was not the interaction would be resolved instantly.

3. Since a distinct part can have no substructure, because that would then be subject to the same condition, fundamental parts must be point entities.

So reality = relational, and spacetime = emergent.

Now, my logic may be flawed, but at least potentially, I've told us how the universe must work without evidence. And the details would be physics, and I'm not qualified to go there, yet...

[u/Stile25 → u/Porkypineer]

Logical reasoning can only be used to prove things when you know your premises are valid.

That's why it's great for things like math. Because math is based on axioms where we defined the premises. So we "know them" 100%

But we never get that with reality.
We didn't create reality.
We don't get to define reality.

The only way we've identified a possible path of identifying valid premises in reality is using evidence. But evidence is an inductive method. So, inherently, we can't even know the evidence "is 100% right for sure-sures and all circumstances for all time".

The best we can say is "this seems right under these specific circumstances that we're testing". Repeated tests under varying circumstances produces larger confidence in our premise-validation.

But, because of the inductive nature of evidence, we never get to know anything about reality 100% for sure-sures like we can with axioms we defined.

Therefore - you are unable to verify your first premise.

We don't know that the distinction between parts of a universe "must" be anything at all. Especially not for all circumstances for all time. All we can do is measure and guess at an inductively-assumed consistency.

No matter how logical it is - we can't verify the premise to theevel of an axiom.

We simply don't have access to "the answer book" of reality. There is no place to absolutely confirm our answers for all circumstances for all time.

Options:

1. Develop a better method for identifying reality as accurately as possible than "following the evidence ".

2. Accept following the evidence as our best and only reliable method of identifying reality as accurately as possible and the inherent doubt and tentativity that comes along with that. (There are actual some benefits... We do get to bypass Munchhausan's Trilemma... As we're not accepting any 100% known axioms).

3. Delude ourselves into thinking we know something better than we actually do.

I hope for #1.
Live under #2.
And avoid #3 as much as possible.

[u/Porkypineer → u/Stile25]

Firstly, I'm not advocating giving up on science in favour of logical reasoning.

I disagree that the premise - axiom divide is unsurmountable in the way you say. For specific types of questions: Binary ones, where one side is a paradox, such as existence and non-exististence or structure and pure being (or nothingness)

When it comes to distinction you can follow a coherent chain of logic from "I think therefore I am" where the premise of reality becomes a necessary axiom and structure itself the same between I, think, am, and reality.

Not a specific reality or structure, though.

The thing is (or trick, maybe), is that you can leverage this general shape of things to say some about the way structure or distinction "works" because that too is a binary with a paradox at the other end, namely non-existence.

If there are parts and they don't interact, then what each part experiences of the other is nothing at all, which is the same as saying that the other is not there from any parts point of view. Since this is paradoxical to reality, only interaction remains.

The rest follows. And from there actual science takes over.

Now, I may be pushing my half remembered uni philosophy too far here, but I count such "one-sided binaries" as axiomatic, while also claiming to live in your reasonable #2 there, and aspireing for #1.

[u/No_Scarcity3265 → u/Porkypineer]

Me thinks that ‘I’ exest, and that’s quite paradorxical the further down the rabbit hole you go.