Logic is perfect

[Arising_uk]

I had asked:

Do you have any particular examples of propositional logic that has the gods bowing in subserviency?

As that is what you claimed you could provide.

Which I did.

I took it to mean that it was so profound that gods, as it's witness, would be left scratching their heads.

I have no idea why you think profundity would be perplexing?

What I meant was that the laws of logic are such that even 'Gods' are subservient to them.

Please enlighten me as to this god perplexing logic.

Just did.

[SpheresOfBalance]

I had asked:

Do you have any particular examples of propositional logic that has the gods bowing in subserviency?

As that is what you claimed you could provide.

Which I did.

I took it to mean that it was so profound that gods, as it's witness, would be left scratching their heads.

I have no idea why you think profundity would be perplexing?
You initially said: "...bowing in subserviency," and since a god is supposed to know of everything, as it created it, everything would be subservient to the god. The only way a god could be subservient to anything, would be not knowing/understanding it, thus perplexing. Simple logic using the classic belief of what a god is, and the only way one could be subservient.


What I meant was that the laws of logic are such that even 'Gods' are subservient to them.
Wrong, if anything, pertaining to gods, the logic is subservient to them, as in it's truest meaning, "gods" created "everything," even your simplistic logic.

Please enlighten me as to this god perplexing logic.

Just did.

No, it was quite elementary.

And by the way, it wasn't the "if" that I was having problems with, it was the "then," as it did not necessarily follow. As an example, you would have been right, if you had said:

Premise 1. If the grass is green, then the sky is blue.
Premise 2. The grass is green.
Conclusion. The sky is blue.

Of course only as an arbitrary example would it have been true, as there is no necessary connection between grass being green and the sky being blue; that the sky is or is not blue is not dependent upon the grass being or not being green.

[A_Seagull]

Something is the case or something is not the case.

It is not the case that something can be the case and can not the the case.

If something is the case then something else is the case. Something is the case. Something else is the case.

The grass is green or the grass is not green.

The grass cannot be green and not green.

If the grass is green then the sky is blue. The grass is green therefore the sky is blue.

There is a 'God' or there is not a 'God'.

'God' cannot exist and not exist.

If there is a 'God' then there is a 'Devil'. There is a 'God' therefore there is a 'Devil'.

The propositional logic you refer to is only 'rational' in an entirely abstract world, where many words are treated as simple labels and without meaning.

When you try to apply these to the real world then any deductive integrity is lost.

So your 'the grass is green or the grass is not green' is only 'true' within an abstract logical system.

Also your 'There is a 'God'....' is without logical foundation.. (as I am sure you realise).

[HexHammer]

Something is the case or something is not the case.

It is not the case that something can be the case and can not the the case.

If something is the case then something else is the case. Something is the case. Something else is the case.

The grass is green or the grass is not green.

The grass cannot be green and not green.

If the grass is green then the sky is blue. The grass is green therefore the sky is blue.

There is a 'God' or there is not a 'God'.

'God' cannot exist and not exist.

If there is a 'God' then there is a 'Devil'. There is a 'God' therefore there is a 'Devil'.

The propositional logic you refer to is only 'rational' in an entirely abstract world, where many words are treated as simple labels and without meaning.

When you try to apply these to the real world then any deductive integrity is lost.

So your 'the grass is green or the grass is not green' is only 'true' within an abstract logical system.

Also your 'There is a 'God'....' is without logical foundation.. (as I am sure you realise).

This is a waste of time, circular logic and poor logic that doesn't account for even the minute abstract variable, there's no "maybe" or "partially" in your equations.

[A_Seagull]

[]This is a waste of time, circular logic and poor logic that doesn't account for even the minute abstract variable, there's no "maybe" or "partially" in your equations.

So we can conclude that logic is not 'perfect'?

And that in fact formal logic is a fairly useless method for inferring knowledge about the real world?

This would rather make sense since perception is essentially an inductive (as opposed to deductive) process; and so everything that follows from perception must also, necessarily, be inductive.

[Arising_uk]

You initially said: "...bowing in subserviency," and since a god is supposed to know of everything, as it created it, everything would be subservient to the god. The only way a god could be subservient to anything, would be not knowing/understanding it, thus perplexing. Simple logic using the classic belief of what a god is, and the only way one could be subservient.

My use was of compliance and 'Gods' or not they will have to comply to Logic, if they wish to be a thing or state of affair that is.

Wrong, if anything, pertaining to gods, the logic is subservient to them, as in it's truest meaning, "gods" created "everything," even your simplistic logic.

The only thing that 'creates' Logic is the existence of things or states of affairs, as such 'Gods' are subservient to their creations and that logic also applies to their own existence.

No, it was quite elementary.

I find the elementary profound.

And by the way, it wasn't the "if" that I was having problems with, it was the "then," as it did not necessarily follow. As an example, you would have been right, if you had said:

Premise 1. If the grass is green, then the sky is blue.
Premise 2. The grass is green.
Conclusion. The sky is blue.

Of course only as an arbitrary example would it have been true, as there is no necessary connection between grass being green and the sky being blue; that the sky is or is not blue is not dependent upon the grass being or not being green.

My apologies I was not clear enough with this example and your study of logic appears to have missed out deduction, so I was not trying to use the material conditional(if...then...) to prove anything, I was trying to show how deduction works, it should read 'If it is true that if the grass is green then the sky is blue. The grass is green. Therefore the sky is blue'. P->Q, P, Q or P :- Q.
Clearer for you?

[Arising_uk]

The propositional logic you refer to is only 'rational' in an entirely abstract world, where many words are treated as simple labels and without meaning.

You think labels meaningless?

When you try to apply these to the real world then any deductive integrity is lost.

I disagree,

http://www.amazon.co.uk/Logic-Problem-S ... 0444003681.

The machine you type upon is essentially a whole bunch of 'not and' and 'not or' gates or propositional formulas, so I think Logic very applicable to the real world. Deduction itself has recently(a few decades back) been automated so I'd advise anyone in a job that mainly involves just that to be looking for a new job as like the number-crunchers such jobs now have a limited life span.

So your 'the grass is green or the grass is not green' is only 'true' within an abstract logical system.

I think differently, go and look at a lawn.

Also your 'There is a 'God'....' is without logical foundation.. (as I am sure you realise).

As I told SoB, I was not trying to prove existence with the material conditional, I was just demonstrating the perfection of deduction. I well understand that Logic cannot prove empirical truths, we have Science to do that know and Aristotle is dead in this respect. What Logic can do is show one the boundaries and point out the contradictions by deduction.

[Arising_uk]

This is a waste of time, circular logic and poor logic that doesn't account for even the minute abstract variable, ...

Er! Propositional Logic is full of abstract variables, what do you mean by "minute abstract variable"? Or are you just talking nonsense and babble from ignorance.

there's no "maybe" or "partially" in your equations.

Ignorance it is then, as if we take "maybe" as "don't know"(which is pretty much what it is) then we can have a Three-valued Logic to play with and if we take "partially" to mean assigning a probability than there are Probabilistic Logics out there as well.

[Arising_uk]

So we can conclude that logic is not 'perfect'?

What do you mean by "perfect" in this sense?

And that in fact formal logic is a fairly useless method for inferring knowledge about the real world?

It can't infer any empirical knowledge? We have Science for that, what it can do is deduce contradictions from such truths, of course Science uses Maths for this in the main but Logic is the philosophers tool and is very useful in certain discussions. It also lays out the boundaries of what is necessary, impossible and contingent, with the contingent being where the empirical truths lie.

This would rather make sense since perception is essentially an inductive (as opposed to deductive) process; and so everything that follows from perception must also, necessarily, be inductive.

But once you've inducted, deduction can be a useful tool in discovering contradictions.

[A_Seagull]

The propositional logic you refer to is only 'rational' in an entirely abstract world, where many words are treated as simple labels and without meaning.

You think labels meaningless?

Labels themselves are without meaning. Their meaning depends upon what they are attached to. The problem with propositional logic is that it acts on the labels themselves rather than the concepts to which they are attached.

When you try to apply these to the real world then any deductive integrity is lost.

I disagree,
The machine you type upon is essentially a whole bunch of 'not and' and 'not or' gates or propositional formulas, so I think Logic very applicable to the real world. Deduction itself has recently(a few decades back) been automated so I'd advise anyone in a job that mainly involves just that to be looking for a new job as like the number-crunchers such jobs now have a limited life span.

I am not saying that logic is not useful, just that it cannot be applied to the real world directly.

So your 'the grass is green or the grass is not green' is only 'true' within an abstract logical system.

I think differently, go and look at a lawn.

I just did, and my grass is a sort of greeny - brown. It could be green or it could be not-green, it depends a bit on the lighting. The trouble is that there is no deductive process for determining whether it is actually green or not.

[A_Seagull]

So we can conclude that logic is not 'perfect'?

What do you mean by "perfect" in this sense?

Just the same meaning of the OP where it was claimed that 'logic is perfect'.

And that in fact formal logic is a fairly useless method for inferring knowledge about the real world?

It can't infer any empirical knowledge? We have Science for that, what it can do is deduce contradictions from such truths, of course Science uses Maths for this in the main but Logic is the philosophers tool and is very useful in certain discussions. It also lays out the boundaries of what is necessary, impossible and contingent, with the contingent being where the empirical truths lie.

I agree that logic can be useful for identifying problematic areas in scientific theories that purport to model the real world.

This would rather make sense since perception is essentially an inductive (as opposed to deductive) process; and so everything that follows from perception must also, necessarily, be inductive.

But once you've inducted, deduction can be a useful tool in discovering contradictions.

But any logical conclusions that follow from the base of induction must then be considered to be inductive and not deductive.

[Wyman]

Arising:

Deduction itself has recently(a few decades back) been automated

What are you referring to there?

[Wyman]

But any logical conclusions that follow from the base of induction must then be considered to be inductive and not deductive.

I don't know if that follows. Or the claim earlier that perception is inductive and therefore anything derived from perception is inductive. I don't know if these propositions are true or not, but they are not readily apparent to me and do not follow in the logical sense of 'follow.'

If you arrive at a set of axioms by 'induction' and then proceed to derive a deductive system from those axioms and the rules of logic, I don't see how that deductive system is then inductive. It is, rather, a deductive system with inductively arrived-at axioms.

Take the historical example of geometry. The Babylonians and Egyptians had certain rules of thumb passed down through the ages. They were useful in engineering and astronomy. Presumably, they were arrived at by inductive processes - patterns were seen over and over again until someone generalized them.

The Greeks created a deductive system of geometry by reordering the known theorems of geometry. They found a set of axioms from which all known theorems could be proven. But more importantly, many, many other theorems, previously unknown, were then derived from within this system. These further theorems were not arrived at by induction at all. A million years could have gone by, without this formalization of geometry, and humans would not have inductively stumbled upon the many theorems arrived at by formal deduction.

So perhaps you are saying that the method of choosing axioms is based on induction?

[SpheresOfBalance]

You initially said: "...bowing in subserviency," and since a god is supposed to know of everything, as it created it, everything would be subservient to the god. The only way a god could be subservient to anything, would be not knowing/understanding it, thus perplexing. Simple logic using the classic belief of what a god is, and the only way one could be subservient.

My use was of compliance and 'Gods' or not they will have to comply to Logic, if they wish to be a thing or state of affair that is.

Wrong, if anything, pertaining to gods, the logic is subservient to them, as in it's truest meaning, "gods" created "everything," even your simplistic logic.

The only thing that 'creates' Logic is the existence of things or states of affairs, as such 'Gods' are subservient to their creations and that logic also applies to their own existence.

No, it was quite elementary.

I find the elementary profound.

And by the way, it wasn't the "if" that I was having problems with, it was the "then," as it did not necessarily follow. As an example, you would have been right, if you had said:

Premise 1. If the grass is green, then the sky is blue.
Premise 2. The grass is green.
Conclusion. The sky is blue.

Of course only as an arbitrary example would it have been true, as there is no necessary connection between grass being green and the sky being blue; that the sky is or is not blue is not dependent upon the grass being or not being green.

My apologies I was not clear enough with this example and your study of logic appears to have missed out deduction, so I was not trying to use the material conditional(if...then...) to prove anything, I was trying to show how deduction works, it should read 'If it is true that if the grass is green then the sky is blue. The grass is green. Therefore the sky is blue'. P->Q, P, Q or P :- Q.
Clearer for you?

Your demeaning demeanor is not required, as always, I just want people to say what they mean, and mean what they say. There should be no room left for assumption as that in fact might lead someone astray, much like say, a gnu, maybe??? So your words are contradictory sometimes, hey? Does it really make a difference if it's a gnu or one that's not very clear?

Yes, I got to give that one to you, as no one is perfect, right? We all make mistakes, true? It's not really necessary to keep score either, is it? Because I mean, someone is now where we were, and we are now where someone else was, yes? 'Time,' simply being the course in ones learning. And then there is change so that one might have to relearn, to keep up with the current belief?

Happy Holidays, everyone!

[HexHammer]

[]This is a waste of time, circular logic and poor logic that doesn't account for even the minute abstract variable, there's no "maybe" or "partially" in your equations.

So we can conclude that logic is not 'perfect'?

And that in fact formal logic is a fairly useless method for inferring knowledge about the real world?

This would rather make sense since perception is essentially an inductive (as opposed to deductive) process; and so everything that follows from perception must also, necessarily, be inductive.

In some cases formal logic does indeed have its merit, like chess where it can come down to raw math, how to distribute water and drive a car, etc so even a computer can do the calculation far better than humans, but when it comes to a simple conversation a computer falls flat as it requires abstract logic which formal logic can't do.