Criticism on Propositional Logic

Easy now boys (Someoneisatthedoor and someemofag)… let’s not stone PoR yet…

You edited your post Someoneisatthedoor. But I still agree.

Yeah, a whole day of insulting people wasn’t going down too well with the moderators…

The whole problem with PL is this, it set up the gramar then says true or false. how can gramar in themselves be true or false?

if I say proposition A is true, what on earth does that mean? you must put a proposition in place of A. but that would be recalling to experience. so I said the truth falsehood of a proposition is dependant on experience alone.

to simply claim something is true or false is meaningless. just as saying true or false in relation to German or French gramar is meaningless if not absurd in extreme.

in relation to ~(p&~p), that can be verified by experience. the reason you say it is false is because you have never had the experience.

I am not criticising on the generalisation made by logic, but the use of true and false and its self invented rules.

plus I am not talking psudo philosophy, you only call it because you can understand me.

PoR, please listen. PL does not determine whether its propositions is true or false (that is, as you say, an empirical matter), only whether the form of the proposition is valid or invalid; ie. whether the proposition describes a possible state of affairs.

Okay fine. Describe a possible experience where ~(p&~p) is false.
If not, then i will take ~(p&~p) as a universal law since it covers all possible experience.

Pinnacle of Reason you do pseudo-philosophy, admit it. You boast that you don’t like to read others philosophical works because you think you can come up with everything yourself. At least once a week you post on ILP some philosophical proposal that only makes half sense and is later fleshed out by discussion. Philosophy isn’t an internalized process; even great philosophers are indented to the work of others before them.

To you Philosophy must be impossibly personal and it doesn’t count if you can’t take 100% credit. You’re obviously a bright fella, maybe a little conceded, but your need for independence is a problem because your ideas are inaccessible. This isn’t because you are making revolutionary statements on Philosophy. I don’t think I have read anything startlingly new in any of your posts. With this post, for example, you pose very valid philosophical concerns. However you state them in such a way that causes confusion.

When you said, “…set up the gramar then says true or false. how can gramar in themselves be true or false? … to simply claim something is true or false is meaningless. just as saying true or false in relation to German or French gramar is meaningless if not absurd in extreme.”

You could have clarified it easier by stating, “The propositional connectives of classical logic are mostly concerned with two elements: true and false. A statement such as A-is-true is a tautology and since A-is-true is a founding principle of first-order logic it must be assumed then that classical logic is founded on tautologies.” Now I believe this is what you are trying to get at.

If you investigated this notion at all you would learn that other philosophers, such as Saul Kripke, have already worked on this problem. Intuitionistic logic is one such field of philosophy and logic that addresses these concerns. Here is someone else’s explanation since I seem to be incapable of explaining it to people on ILP.

Another example of why using prior work is important is show clearly when you said, “if I say proposition A is true, what on earth does that mean? you must put a proposition in place of A. but that would be recalling to experience. so I said the truth falsehood of a proposition is dependant on experience alone.”

Again if you read other philosophers you would find that David Hume sort of addresses this problem. But more importantly Gödel’s incompleteness theorem expresses this exact thing in logic.

Well I just adopted a puppy so I will be going.

someemofag

I assume David Hume whom you hold in such esteem also talk psuedo philosophy like me. for we are on the same thing.

in all honesty, what you wrote is even more confusing than what I wrote. I write for the people, not for the academics. I write so others can understand. I do not read Hume, or whatever the other guy’s name is. I write because I can think for myself and I want others do the same. that is why I want to bring philosophesr to their knees and expose them as who they really are.

Also, the only reason people are criticising me is because they know what I say, while they do not know what Kant said, so he has less criticism because there is nothing to criticise. Knowledge is alive, not dead so I used to read books, but the problem is, they contain so many problems and ambiguities you can not clarify.

When I think of logic I don’t think content. Sure we can insert true sentences based on experiences into the logical equations that have been created, but much like you I don’t think the purpose is to end up with a truth that couldn’t have been realized beforehand…so I see where you’re coming from, that you could just resort to experience, and for this reason you find logic is simply a game. In this sense you are right; logic is the rules to proper argument. But I think you expect to much from it, and that’s where you find problems. I think of logic as demonstrating ways of taking possibly true statements and maintaining that truth through different methods of reasoning…ways in which you could argue w/o taking a wrong turn and ending up with a falsehood. Basically it gives ur argument validity. To me logic is just the bare bones of what an argument should be and is an example of proper reasoning, through symbols, so that the form can be more easily understood w/o the confusion of content. Im sure your arguments here could be translated into logical form…what would you say then about logic being able to provide truth?

POR

5+4=9 is true by definition, not by observation. One cannot observe + anymore than one can experience =. These describe the relations of ideas and aren’t found in the physical world.

5 isn’t a quality found in an apple.

William Webber

I appreciate your agreement

It sure can, all things are logical because all things derive from experience. by truth if you mean truth of experience, then I agree. but if you mean. A&B is true, then I’ll look at you funny. Truth only exist for a statement, not for the rules of a statement.

Nihilistic

no you [edited at the request of Imp], 5 is a quality found in five appleS.

Russell thought so too, for a while.

Unfortunately, although you can fudge it for numbers on their own, it doesnt make sense with transitive asymmetrical relations, ie, when you try and use those numbers.

If we assume mathematical relations can be reduced to properties then:
If apple A is bigger than apple B, either both apples have the same property, or the group of both apples has a property. However, this would mean “apple A is bigger than apple B” means the same as “apple B is bigger than apple A”, as they both have the same property applied to them.

If you apply a different property to each apple (a size for example), then you will still have a relation (not reducible to a property) between those different properties (or sizes in this case).

The structure of the world is not found in any particular brick.

You are absolutely right, we take true statements, and only use rules to maintain that truth. But now saying this I don’t see why you’d look at me funny if I did say A&B is true.

Let’s assume these statements are true:
A - John is tall
B - David is tall

If we conjoin them we get A&B (‘John and David is tall’). However, this is silly, not because it is no longer true, but because of how we say it. We are allowed to translate it properly, thus finding that the statement ‘John and David are both tall’ remains true.

You might agree more in this case:
A - Nihilistic is a dumbass
B - Oreso is a dumbass

These are both true, so if we conjoined them, ‘Nihilistc and Oreso are both dumbasses’ we have maintained the truth of our original two statements.

I’m hoping this makes as much sense to you as it does to me. No offense to Nihilistic or Oreso. :wink:

“5” is a symble asaigned a value equal to five times the value of the symbol “1”… and the value of 1 is a quality found in an apple.

While it is true that each apple is different… it is also true that no apple is constant in its composition… the world around us is in constant motion and undergoing constant change… therfore there is no “point” where an apple has a uniform composition. however we slip around this problem by defining parameters for when something qualifies as being a member of the class “apple”… and when we say there are 5 apples we are refuring to amount of seperate objects which qualify as being members of the class “apple”…

They do not need to be exactly the same… they only need to qualify as belonging to the class “apple”.

Tell me, does one find numbers in the seeds of the apple, or the fruit? Perhaps the peel holds the attribute of the apple that is 1 or many.

Oneness is not an attribute of the apple, it is an attribute of the relationship of the idea of the apple, at best.

Don’t strain urself… 1 is a value contained within all seperate “identities”

1(A)=A

If Apple-ness is an inherent attribute of the apple then it has identity… and whatever an apple is… 1 is by LOGICAL NESSESITY (it’s axiomatic) a value contained within it.

Lets recap…I say mathematics doesn’t apply to reality, and you try to prove that it does by giving me an equation? Do you see anything wrong with this?

What a waste of time.

oreso

size, number, are all relative qualities. apple A is bigger relative to apple B. the two apples though are linguistically congruent are not physically congruent. as i have explained numerous times. the world is one of particulars but language always universal. as long as the listener understands then the purpose of language is served.

“The structure of the world is not found in any particular brick.” but in the universal of bricks in their particulars.

William Webber

all i am saying is variables in themselves can not be true or false unless substituted with facts from reality. as long as one understand the description, then the language is fine.

though your statement is very persuasive, nevertheless, I disagree with the assumption that Oreso is a dumbass. see, the truth of a proposition is only found in its substitution and not in the form which PL assumes.

Nihilistic

numbers do not exist in nature, but as inventions of man for the purposes of communicating ideas. If i am hungry and I need an apple, I would say, give me one apple. but if i am very hungry, I would say give me ten apples. do you understand my request? if not, then you are not intelligent. which serves only to validate the point made above by another impartial poster. there are no attributes in themselves, but the attributes we assign to them.

all mathematics came about because of human interaction. you can not understand one, because one is invented, but you can use one to interact with the world around us. for this very reason, i ask people to stop studying themselves stupid and worship Jesus.

If mathematics does not apply to reality, then what does it apply to? I have proven that mathematics is derived out of relaity so men can interact with one another on the topic of reality. mathematics is invented by men to define their interaction with reality.

Indeed… you seem a confused individual… i was proving it by appealing to LOGICAL NESSESITY… there is no empirical evidence for logic, other than it’s AXIOMATIC existence… it is self-evident… Unless you wish to argue that logic does not apply to reality (and therby that reality is not uniform and unintelligible), i do believe i have proven my case…

If you DO wish to argue that reality is unintelligible… then I suggest you begin a new thread… and prove your point by appealing to… well… your own personal confusion I guess…

I agree, you still havent answered though. How can you maintain that mathematical concepts are redicible to the properties of groups of objects, when it is self evident that they cannot be properties at all?

5 is not, and cannot be, a property of a bunch of apples.

So, er, wouldnt you say that this “universal of bricks”, is the form of the building?

I must admit, i cant fault your logic. This is an entirely valid argument. :smiley:

Mad Man P

well said! One thing man can never understand is his own confusion.

oreso

if you understand as you claim my previous statement, then this mathematical truth becomes an obvious subsection of language.

the number five is uttered by two people. if I said, I want five apples, and I see three apples. then I say I want more. but if I see six, then I say too much. so until the idi*t gives me the correct apples then I am not happy.

the number five is merely a signifier for human interaction. it does not have a basis beyond the neccesary interaction. so if I say I want 5, it makes no sense. because it is used independently of the apples. it is a mistake to think that 5 is a property of a bunch of apples. but that it is a property we humans assign to a bunch of apples, just like size, which is relative.

so 5 apples, is a linguistic command aimed at producing a conceptual understanding. it is about interacting with the world.

what is the form? all i am saying is different bricks interact in such a way that in their universality produce the world in its entirety.