a -> b) -> (~a -> ~b) is not modus ponens, we can both agree on that now. Fantastic progress. — flannel jesus

OK fine. That's rather quick and easy solution to us all. We have agreement. Thanks.

t's a shock to me that you call it modus ponens, which is a general rule, and then say now that it's not a general rule, without ever explicitly acknowledging that the thing your'e doing is in fact not modus ponens. — flannel jesus

It is a reasoning by contradiction in proof. It is so obvious just by looking at it, both premises and conclusions are contradicted and checked out.

So you don't think it's a general rule, meaning you think there are scenarios where you can have an implication, a implies b, and yet not have the implication of (not a implies not b), is that right? — flannel jesus

I am quite surprised to hear you all the way thought it was MP. MP is the most basic form, and was implemented by the Stoics. If it doesn't suit for the statement you are trying to prove, then you must move on to another type of reasoning.

Oh, fascinating. That's not what it sounded like when you called it Modus Ponens, because Modus Ponens is indeed a general rule. — flannel jesus

There are many different ways proofs can be done. MP is one way to do it, but it was not good for proving cogito, so I tried different arguments to suit it. Is it such a shock? :rofl:

I would love to know who he can make see the light. One person who thinks (a -> b) leads to (~a -> ~b) as a general rule. I'd love to have a conversation with that person. — flannel jesus

Sure, if you keep your control and just concentrate on the topics under the discussion, we can give another try. It is not because I am against using bad languages and swearing. I do swear in real life as much as anyone. Perhaps even much worse than you do. But in the forum, we must keep in control and respect the other party we are talking to. You cannot discuss anything rationally with someone who is not in control of their emotions.

You are judged by only on what you write here. So, check out if you are writing the facts, not the distortions or untruths and dishonest claims before posting. If you are ok with that, then I can give another try for clarifying (a -> b) leads to (~a -> ~b).

By the way, it is not a general rule. (~a -> ~b) is an assertion or inference against (a -> b).
You are trying prove (a -> b) is true or false.
One of the ways it can be done is applying the contradictions to (a -> b), and check if it is true or false with the reality.

So here already, it is clear that you have mistaken the very start of the point (a -> b) leads to (~a -> ~b) as a general rule. It is not a general rule at all. It is a reasoning by introducing contradiction case.

Because it is obvious. — Lionino

It is the most mysterious answer I have heard in the forum, I am afraid. :D

No. Go post that picture of a logic book you were talking about. And also translate my phrase to propositional logic. — Lionino

No Lion. Posting picture of a logic book is not a philosophical process. It is unnecessary. Our linguistic discussions and reasonings should be able to lead us to some sort of conclusion. I was going to explain everything again in detail, if you only let us know what you meant by you said thousands of times, but you were again telling untruths there.

You keep demanding to translate your phrase to PL. It is also unnecessary bizarre act in philosophical discussions. I have never heard such a ludicrous demand. If you read the good logic books, they would tell you with the reasonable inference and introducing assertions for the premises, one can build a logical argument on every event in the world. Obviously you aren't aware of that.

OK, I can only conclude that your motive was not philosophical in this discussion. So, I will leave you to it. I have learnt my lesson that I cannot make the folks to see the light, who are determined not to see it. So I will not keep trying wasting my time. All the best.

Because your bio says something other than what you meant. If anything, it means something funny. — Lionino

I still cannot see any relevance of my Bio to this thread and what we have been discussing. Something other than what I meant? How do you know what I meant? :)

Another case of selective amensia in this thread. — Lionino

I did discuss the argument case with Banno, but never with yourself.
Are you not mistaking me for someone else?
Please tell us what you said about it in summaries and points.

I don't think it means anything. I know what it means. And it is not what you were thinking. — Lionino

But why do you talk about the Bio, in the middle of talking about order and logic? It would help in understanding, if you let us know what you think it means.

I have tried that a thousand times already with "If it rains, the floor is wet". Banno also. It is pointless. — Lionino

Mentioning about Banno or the other folks in the discussion won't help for clarification on the point.
What did you say about "If it rains, the floor is wet."? What is your point? This is the first time I am reading you talking about it.

We can't change all determinants and constraints but we can change some determinants and constraints. It varies from person to person depending on their genes, environments from conception to the present, nutrients from conception to the present, and experiences from the womb to the present. I have not assessed how efficiently we deal with our determinants and constraints.

I don't know if Gods exist and if they are all-knowing and all-powerful. I am agnostic about the existence and nature of all Gods. Humans have believed in and still believe in many Gods. That does not mean that they exist. — Truth Seeker

I agree with you that some people make good efforts for improving and bettering the human living conditions which are under the negative inherent determinants and constraints. I do hope they will make good progress, and suppose that is actually what most of the public works are about.

You also mentioned the existence of God, and your agnostic attitude on the existence.
I think it is an interesting comment. It tells me that you think you know what God is, but you are not convinced it exists. Because one cannot be agnostic without having reasons for being agnostic, and it follows that one cannot have reasons for being agnostic without knowing the concept of God.

Therefore it follows that your thinking and knowing God's existence doesn't necessarily warrant the existence of God to yourself.

What would give you 100% certainly of the knowledge for the existence of God? What do you need for you to believe in God's existence with 100% certainty?

Some of the determinants and constraints can be changed.

For example:
1. Gene therapy.
2. Changing the environment by moving to a different part of the Earth.
3. Giving aid to famine victims who are dying from not having enough nutrients.
4. Rescuing people from modern slavery and giving them treatment for PTSD if necessary.

Of course, many of the determinants and constraints can't be changed by the subjects and they need external help from others e.g. doctors, aid workers, police officers, paramedics, etc. — Truth Seeker

But do you think that humans with the restricted abilities are able to deal with the inherent determinants and constraints efficiently, even if they tried?

Would you not agree that the inherent determinants and constraints are rather in the domain of God, who are omniscient and omnipotent?

It means Google translate does not work properly. — Lionino

Why suddenly talk about the bio written in Latin? What do you think it means?

By the way, your bio does not mean what you think it means. — Lionino

What do you mean? Could you please explain on that point?

I did not run away all the times you posted nonsense, in fact I refuted you several times. And I refuted you again, your rendition of Descartes is wrong. Make some effort to actually read what he wrote. — Lionino

Even if a sentence is order form, it can be formalised and executed in the logic.
If you read anything about mathematical logic, then you would have known that many of the computer programming languages operate on the instructions executed under the Boolean logic in the order form.

For example, if total order >= 10$, then offer FREE shipping.

Therefore, your claim that sentences in order form are not Logic is not correct.

Yes, "drive away if there is a red light" is an order (drive away) with a conditional (if there is), it has nothing to do with statements of the type p→q. It is a bad example. Choose another one. — Lionino

You have changed my original example back to front to make it sound like order. Please read my original example given to you again, and confirm.

The example sentence in the logical form is not order at all. It can be expressed different way for the same meaning, if you have linguistic problem understanding the sentence. For example,

If it is red light, then it is safe to drive.
If it is red light, then it is legal to drive.
If it is red light, then it is ok to drive. ... etc.

The argument is made up into the formal sentence form in the argument.

It is only an order, if some one tells you to your face, "When it is is red light, drive", or as you have changed it "Drive away, if there is a red light."

You see, the number in the bottom left corner shows whether a message came up after or before. — Lionino

I have been away all day, and just returned to see your message to me. I have no clue what you were talking about on how time works. But I will catch them up when I have some spare time.
You see I don't read any other posts apart from which are directed to me.

I did not run away all the times you posted nonsense, in fact I refuted you several times. And I refuted you again, your rendition of Descartes is wrong. Make some effort to actually read what he wrote. — Lionino

When I asked you about the If Red Light then Drive logic for your agree or disagreement on it, you said it was order, not Logic. It is a logic. It gave the impression that you were trying to avoid the answer.
That logic is a critical one. We will examine that tomorrow. I will try to read what you sent me in full in due course.

For some reason unknown to us, he is not able to take on new information. — Banno

Banno, we all know that you keep scanning other folks messages for sussing out the irrelevant grounds for your attacks. If you are honest, you will see and admit that I have never spoken to anyone with out of context vulgarities under any circumstances. I always kept my control in respecting others in the discussions.

There are a few of your cliques who have been throwing irrelevant out of context insults with the vulgar languages umpteen times. It just shows that they don't have basic respect for others, and disregard the manner of the discussions. But you never point out the problems of these folks because they are in your cliques.

With just this one evidence, your bizarre post is an unfair and untrue criticism of yours based on your psychological bias. I hope that you could realise the reality and be able to see the true situation.

woof, woof, growl. — Banno

Calm down Banno. This is The Philosophy Forum. :nerd:

Further conversation becomes like a child hitting the dog's cage with a stick. It will bark and growl back at you; fun, but progress will not be made. — Banno

Seriously this is your problem Banno. You think you are a teacher, and the rest of the members are the students. But you have no knowledge of the field that you claim to be knowledgeable at. Your claims are full of misunderstandings. When it is pointed out, you get upset, and then you put out unfair and untrue ad hominem.

I tried to treat you with my best fairness and friendliness this time. But it is over the limit. Your insincerity, dishonest and pretensions are too obvious in your post. It is a regrettable affair to be honest.

Wow, so on top of not having ever read Descartes and feeling the gaul to comment on it, on top of not knowing how to use logic, you also don't know how time works? If you scroll up, you will see I requested that you translate my phrase before you deflected with that "question" of yours. — Lionino

Well, you keep running away from the question with smoky gibberish. How time works? Why do you suddenly want to know how time works? Please elaborate further.

I don't care about your gibbersh. You said: — Lionino

Do you agree the orders and rules must be expressed in sentences, and the sentences must have truth values to be effective as the orders and rules?

If that is true, translate "If you had been there, you would have seen that the fireworks went off at the same as the bell rang" to formal logic. — Lionino

I have asked you first, but you never answered my question. Is this the way you evade the question which will collapse all your points?

No, you said any sentence can be put into logic. Put my sentence into logic. — Lionino

Do you agree the orders must be expressed in sentences, and the sentences must have truth values to be effective as the orders?

No, you said any sentence can be put into logic. Put my sentence into logic — Lionino

You must be joking telling anyone putting your sentence into logic. Are you Descartes?

Proving your absurd claim. — Lionino

I am just telling you what is correct from the muddles that you folks have been spewing out. I am not trying to get out from anything like some of the senseless folks here try to make out.

Proving your absurd claim. — Lionino

That doesn't prove anything at all. If you exist, you can think, or you don't have to think. It just means, in order for you think, prior to that, you must exist.

Yes you do. You said every sentence can be translated to logic. Translate my sentence to logic. — Lionino

What's the point of that? What would anyone gain translating what you are saying into logic?

Your example has nothing to do with propositional logic, having the word "then" in it does not make it so. — Lionino

You say it is order, not logic. That is nonsense. Orders are expressed in sentences. The sentences must have truth values to be effective as law or order.

That is not my sentence translated to logic, I am afraid. — Lionino

I am not sure what you mean here. You obviously are avoiding to answer for the question whether you agree or disagree with the example propositional logic shown calling it order, not logic.

My prediction is that you will not translate the sentence into logic. — Lionino

Sentence is the basic constituent of Logic. What do you think Logic is?

They are not, which is why no scholar says Descartes' argument is contradictory. — Lionino

The only basis for your claim, they are not, is because no scholar says D's argument is contradictory?

On what basis do you have this wonder, since you have basically admitted that you didn't read him at all? — Lionino

Your claims on D seem to be based on some type of religious beliefs rather than academic theories.

If red light, then drive away.
— Corvus

That is an order, it has nothing to do with logic. It is not how A→B is used. — Lionino

Any event which can be described in human language can be translated into the formal logic. It is called propositional logic.

Do you agree or disagree with this logic?

If red light, then drive away. R -> D
If not red light, then don't drive away. Not R -> Not D is False
Therefore If red light, then drive away. R -> D is False

↪Bylaw I figured. — Lionino

His wild imagination has no ground. Just someone said his native language is Korean doesn't prove that he is a Korean. His repeated meaningless citing on the point is very strange and irrelevant for the discussion. If you listen to him, and thinks it makes sense, it proves that you have no ability to reason.

That is not the premise, that is where he starts his investigation.

I doubt everything. (P1)
But I don't doubt Thinking. (P2)
— Corvus

The two premises are contradictory. Not that it matters, because Descartes never said anything like this. I can only recommend reading Descartes. — Lionino

Far more wild premises are made up and forwarded as some reasons why the contradiction reasoning is not the case by the other folks. Those are not said or written by Descartes, but they are reasonable and interesting inferences for the premises of cogito.

In logical arguments, premises are made up with reasonable inferences and assertions. Nothing like talking about hosing a garden, when the argument was about the rain and wet ground.

If Descartes had said or written about the basis for cogito, then no premises would be necessary. Because the only basis for cogito was his doubt on everything he perceived, the premises from the reasonable inferences were asserted in the post.

I wonder if you read any Descartes at all yourself.

You don't seem to know even the difference between validity and truth.

That's kinda why I have been backing up and checking what I have writ with the tree generator. — Banno

The tree generator you keep brining in doesn't deal with applying the contradiction reasoning. It just generates trees and checks for validity. It cannot tell you a formula is true or false mate.

Any logic text you choose.

That's kinda why I have been backing up and checking what I have writ with the tree generator.

(Edited - I assumed the wrong author) — Banno

Logic books? That's a poor logic of you again. If someone with poor logic or weird mind wrote some logic books and published (anyone can publish books by themselves via amazon these days), and if you happened to pick one up and read it, then you would believe in whatever is in the book.

You got to use your own loaf. Of course you read the books, but you must be able to apply the logic into the real life examples not parroting away what you read or seen.

I have thought this again, but it is clear what I say is correct. It is simple, but you don't see it for some reason.

(t -> e) -> (Not t -> Not e) This is via the contradiction reasoning.
This can be replaced with
T -> E
E = False
Therefore T = False

This is nothing to do with (t -> e) -> (Not t -> Not e) doesn't follow of your logic.
When you are applying the contradiction principle, it gets applied to both T and E.
Not just E or just T.

I am going out now, and will be back later. Would be interested in what you got to say about it.

It's not just my logic. — Banno

Who else is saying what you have been saying? Although, it doesn't matter how many folks are saying the same thing. Ultimately what matters is the truth. Later~

Are we now playing "posts last wins"? — Banno

No, that is not my game. You mistook me for some other folks in the thread.
I am just trying to understand your logic here. There are parts in your claims which is not crystal clear.
I will think over, and will return with my thoughts on your point. Enjoy your gardening. Cheers mate.

And from "If it rains, the ground will be wet" it does not follow that "If it does not rain, the ground will not be wet". I can hose the ground, and rocks exist without thinking. — Banno

Are you still claiming that when you stop thinking, you cease to exist is true? I am saying that is False.
Rocks existing without thinking is totally irrelevant. It doesn't rain, then the ground is not wet was given as an example to let you see, that Not t - > Not e is telling something, not nothing.

However, we are talking about Cogito (I think) here.

from "If it thinks, then it exists" it does not follow that "If it does not think, it does not exist". — Banno

It is not about follow. It is about introducing assertion and inference.

It seems not, but
Are You Not Entertained?
— Maximus, and Banno — Banno

I am. :nerd: Banno claims that he ceases to exist when he doesn't think. :rofl: