It is in the heading : Most Fundamental Branch of Philosophy — A Seagull

By most fundamental I mean which comes first; which one is the bedrock.

What is 'most important' and 'where to start' are two different questions. — A Seagull

The original question was which comes first, meaning where to start. I don't recall asking which branch is the most important.

Why?

The trunk cannot exist without the roots and leaves
The roots cannot exist without the trunk and leaves
The leaves cannot exist without the roots and trunk.

Philosophy has to be holistic or it is nothing. — A Seagull

Why do we keep coming back to the tree analogy?
If philosophy has to be holistic, then shouldn't it include a metaphilosophical theory that shows us where to start?

To my knowledge, none of them contradict any other one, — Harry Hindu

Well there is the family of liar paradoxes, which some would say shows a "contradiction" in the classical laws of logic.

So while we only have our experience to go by, the experience of billions using the same theories and getting the same results is something to be said about the method by which we've been able to achieve this - science and logic. — Harry Hindu

I tend to agree with this. I just didn't know what you meant by element of truth.

I think that you are confusing a galaxy with a picture of a galaxy. — Harry Hindu

Let me rephase: As far as I am aware, the human mind is not currently capable of conceiving of an entire galaxy; it's too big for us to be able to picture the scale of it in our heads. Just because we can't conceive of something doesn't seem to imply it is impossible to actually exist.

It seems to me that you are engaging in epistemology/metaphysics in order to justify logic. To me it seems that in order to select the axioms of logic, we have to use epistemology/metaphysics to avoid being arbitrary. But it also seems that in order to make distinctions in epistemology/metaphysics we need a system of logic. Like I said before, this appears similar to the problem of the criterion.

It needs leaves too. — A Seagull

Except during the winter. The tree analogy is not an infallible way of depicting how philosophy works. So how about instead of "branches" we say "subfields".

Does a tree have a 'most important' branch? — A Seagull

Maybe not, but it needs roots. Let's not take the tree analogy too far though.

Really? Which metaphysical and epistemological problems need to be solved prior to understanding, or being able to use, logic? Tell me how you answer that question without using logic. — Harry Hindu

Which logical axioms should we accept?

If something is useful then that implies that there is some element of truth. — Harry Hindu

I think that depends on what you mean by some element of truth. Newtonian mechanics is wrong but useful.

Why is a contradiction false? It's because actually picturing a square-circle in your mind is impossible. — Harry Hindu

Picturing an entire galaxy in your mind is impossible.

So what useful assertions can be made in the fields of epistemology or ontology where the conclusion doesn't follow the premise, or that you don't need to provide reasons for your conclusion? — Harry Hindu

This is why I am not outright saying one of these fields should be first. It seems like metaphysics/epistemology depend on logic, but logic depends on metaphysics/epistemology. Analogous to the problem of the criterion.

Then dialetheism both denies and assumes the law of non-contradiction. How is that statement useful? — Harry Hindu

What do you mean by useful? If you mean how is it relevant to the discussion, well dialetheism goes to show that the foundations of logic are disputed, so how do we find a 'correct' logic? If we use logic to establish logic, this would be circular.

You mean it habitually works and provides useful information via deduction and induction. — Harry Hindu

Are you implying that because something habitually works that it is true/correct?

This is an interesting question that I think about quite often. A lot of people may say that the reason humans are more valuable than animals is our consciousness, and this justifies us eating them. But if aliens could have a higher level of consciousness than us, then they are justified in doing what they want with us. One reason why meeting aliens might be our undoing. As to your question, if we assume panpsychism, I'd say: why couldn't there be organisms that are more conscious?

So, you don't seem to be disagreeing with me that logic is a fundamental field of philosophy, rather you are disagreeing which form of logic is more fundamental? — Harry Hindu

Let's just say I don't necessarily agree that logic is first. It seems that if we want our logical system to be justified/true we will need to employ epistemology or ontology/metaphysics, otherwise we're in danger of arbitrarily picking axioms.

You then mention dialetheism that, you say, denies the law of non-contradiction, yet is it true or not that dialetheism denies the law of non-contradiction? :gasp: — Harry Hindu

This question is already assuming that the law of non-contradiction to be the case, so I'd imagine a dialetheist would answer by saying that the question is not well formed.

Did you not identify what dialetheism is and what it is not? It seems that you can't escape using the laws of non-contradiction, identity and exluded middle, even when distinguishing different types of logic and fields of philosophy. — Harry Hindu

Yes of course you can't escape the classical laws of logic if you assume the classical laws of logic. Just like if you wore red sunglasses you wouldn't be able to escape seeing everything as red until you take the glasses off. The reason why I personally find it hard to escape classical logic is probably because it is habitual.

Politics for me. — Gmak

This is a philosophy forum. So naturally my next question is: why?

Is there an incorrect system of logic? How would you know that you are thinking meaningfully or making useful statements about any topic - especially epistemology - without the logical rules of non-contradiction, identity, excluded middle, etc.? — Harry Hindu

There are several conflicting systems of logic. For example, dialetheism denies the law of non-contradiction. https://plato.stanford.edu/entries/dialetheism/ Even the axioms of logic are disputed. So how do we know which system to use?

Earlier you said

We won't know if we have the correct answers — BitconnectCarlos

This seems to be implying skepticism. I would agree with you that the existence or non existence of a god likely can't be derived through reason alone.

We won't know if we have the correct answers — BitconnectCarlos

So we don't have hope against defeating skepticism?

I believe the nature of truth itself depends on whether we adopt a theistic/pantheistic/atheistic framework. — BitconnectCarlos

Interesting. Do you mind explaining?

Metaphysics. — BitconnectCarlos

But how do we know that we have the correct answers? How do we go about investigating reality (epistemology)?

Logic is the most fundamental branch of philosophy — Harry Hindu

My question would be how do we know we have the correct system of logic? Wouldn't we have to do epistemology first?

No, you do not. Read the definition of "axiom" that you quoted again. — aletheist

You are right; my example is not a good one. But the way I see it, no beliefs/truths are self-evident.

It is not so much your individual inability as the fact that no one can be a complete skeptic--again, such a position is self-defeating--so it then becomes a matter of which beliefs you adopt, just like anyone else. — aletheist

This is probably true, but adopting beliefs would not consist of knowledge, which is what I want.

Right back at you. — aletheist

All of your objections to my position are very common. I understand your objections, but they do not hold up. I think I am going to stop arguing with you, so I advise that you watch carneades.org playlist "In defense of skepticism".

how on earth is anyone supposed to have a meaningful conversation with you? — aletheist

As I explained previously, I only say how things appear to me. This allows for a conversation.

Anyway, I suggest looking up the definition of "axiom." — aletheist

axiom: a statement or proposition which is regarded as being established, accepted, or self-evidently true
I could assert that "my big toe is purple" is an axiom, but I need to demonstrate that it is true. Same with other axioms. You should look into Agrippa's Trilemma a bit more.

Now you are asserting that an assertion is not an assertion--self-defeating, just like I said. — aletheist

I did not say that as an assertion. And I AM NOT asserting this either.

See, you just used modus ponens. "If I have nothing else to allow me to hold a conversation, then I have to utilize appearances. I have nothing else to allow me to hold a conversation. Therefore, I have to utilize appearances." — aletheist

Again, I may not be able to help but use deductive logic, but how does my inability to be a complete skeptic have any bearing on skepticism as a position?

We have exchanged several posts now, all utilizing the English language. Unless you wish to claim that we have been throwing gibberish at each other, clearly you and I both have knowledge of the English language. — aletheist

This might not be the same as propositional knowledge, which is the knowledge that I am talking about.

If you're saying that because I use the English language, I know how it works, this seems to be flawed reasoning. Just because someone uses their brain doesn't mean they know how it works.

Overall, no offense, but I don't think you understand my position at all. Check out the Youtube channel carneades.org (he's better at explaining things than I am).

This is your third assertion in a row that something is true. — aletheist

Again, I'm not asserting my statements/positions as definitely true. This is how it appears to me. INCLUDING THIS.

Why should I believe you? — aletheist

Maybe you shouldn't.

The inference rules of deductive logic, including modus ponens, are intrinsically truth-preserving; if the premisses are true, then the conclusion is true. What deduction cannot guarantee is that the premisses are true. — aletheist

But the axioms that classical deductive logic employs are unsupported.

They are intrinsically true so long as the original presupposition rings true. I think that's the point he's trying to lay out. — ISeeIDoIAm

Exactly.

Another assertion that something is true. Do you not realize that thoroughgoing skepticism is self-defeating? In order to be consistent you would have to be just as skeptical about skepticism as you claim to be about everything else. — aletheist

Again, this is not an assertion. This is how it seems to me. I have to utilize appearances, as I have nothing else to allow me to hold a conversation. Skepticism the position doesn't seem to be self defeating. However, if skepticism as a way of action is incoherent, this is probably due to human fallibility. And I am skeptical of my skepticism (or at least it appears that way). It could be that someone does have knowledge, but as of yet I haven't found any.

How do you know that you do not know anything? How do you know that you want to have knowledge? — aletheist

I do not know this. I could be wrong. However, skeptics like me do not assert as true what we're saying. We just explain how it appears to us to be able to hold a conversation.

We already have, but you claim not to accept it, even though you cannot avoid employing it. — aletheist

Have we? Deductive logic (at least classical) seems unable to guarantee the conclusions it validates. I do admit that I probably cannot avoid employing it, but this has no bearing on whether it allows us to know.

Good point. But I am also skeptical of the linear thinking; I use probably because I'm hardwired that way.

Ironically, you seem to apply modus ponens to this argument (If there is a requirement for linear propositional support, then we must embrace skepticism; there is such a requirement; therefore, we must embrace skepticism) — Nagase

I don't necessarily think that propositions need linear support. In fact, it seems that this kind of linear analysis is flawed (because of Agrippa's Trilemma and other problems), however, nonlinear analysis seems to me to be unable to avoid circular reasoning. If I am mistaken, please enlighten me. I am relatively new to philosophy; I have been an autodidact for about a year now.

My stance is that I do not know anything, but I (really) want to have knowledge, so I continue the search. I wouldn't say that nothing has meaning, because it is possible that something is intrinsically meaningful, but I am just ignorant.

I think Tim layed it out nicely: no matter what game we play the rules must be established first before any player can proceed — ISeeIDoIAm

Yes, I tend to agree that rules need to be established, but the question is how do we go about establishing the rules. How do we establish a system of logic that allows us to know?

If that is your definition of justified, then modus ponens is entirely justified, since it always takes us from true beliefs to true beliefs. — Nagase

You seem to be using modus ponens to support modus ponens. 1) If that is your definition of justified, then modus ponens is entirely justified. 2) That is your (read:my) definition of justified. 3) Therefore modus ponens is entirely justified (from 1 and 2 modus ponens).

Also you seem to assume that if a rule goes from true beliefs to true beliefs, it is justified. Once again, this is using modus ponens to prove modus ponens. This is the point behind Carroll's story. For Achilles to justify modus ponens, he has to assert modus ponens.

How do you justify that definition? — aletheist

This is how I am choosing to use the word.

How do you justify that assertion? — aletheist

Again, this is how I am using the word.

How do you justify that response? — aletheist

Because I don't know. And no I don't know that I don't know. Maybe I do know, I just don't know it.

How do you justify that self-characterization? — aletheist

I am not saying this as an assertion; skeptics compose sentences like this not to assert something but to describe the way it appears.

How do you justify that judgment? — aletheist

That's why I included the word seem. I could be wrong, but others have not met the burden of proof.

If you have questions about skepticism, check out the YouTube channel carneades.org and his series in defense of skepticism. However, this is not really the topic of this discussion. I am specifically interested in discussing deduction.

By justified I mean entailing that a person can believe the proposition and stay rational. The justification is what connects a belief to whether or not it's true. You might ask how something might be justified, I'd say I don't know. I am a skeptic. All methods of justification seem flawed to me, including deduction.

I'd say we're using simple questioning to argue that deductive logic is flawed. However, if deductive logic shows that deductive logic is flawed, then deductive logic is flawed.

Yes but the point is that modus ponens is not justified in the first place.

The tortoise is not being intransigent; it seems that he is exploiting a weakness in the rules. Or I guess you could say he is questioning the game itself.

Deductive logic seems to require modus ponens to justify modus ponens. As in: 1) If a rule of inference is truth-preserving, then it is an acceptable rule of inference. 2) Modus ponens is truth-preserving(from truth tables). 3) Therefore modus ponens is an acceptable rule of inference (from 1 and 2). This is the problem posed by the tortoise. Accepting C (in the story) is accepting modus ponens. However, because of the problem with modus ponens, the tortoise must accept D, E, etc. to arrive at Z.

You're right, I cannot force you to agree the sky is blue. That doesn't necessarily mean there is a defect; maybe there is a defect in the method of argumentation.

It seems that the tortoise is revealing a problem with deduction, specifically modus ponens. In order to accept Z you must accept modus ponens (C). Then in order to accept Z you have to accept modus ponens (D). It seems that we must use either circular reasoning or an infinite regress to support modus ponens.