## What are the achievements of Logic?

What is the basis for reason? And mathematics?

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A_Seagull
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### Re: What are the achievements of Logic?

Arising_uk wrote:
Mon Jan 29, 2018 3:21 pm
Dapplegrim wrote:What are the achievements of logic? It would seem to be hard to identify them. ...
The computer you type upon is designed upon it.
Does philosophy need this form of logic? If so what for?

Does anyone have any suggestions?
Reasoning.
The computer uses the logic of mathematics not the so called 'laws of logic'.

I am not at all sure that reasoning actually requires a formalisation of logic in the form of the 'laws of logic'

Which brings us to the question: 'What is logic?'

Eodnhoj7
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### Re: What are the achievements of Logic?

A_Seagull wrote:
Mon Jan 29, 2018 10:13 pm
Arising_uk wrote:
Mon Jan 29, 2018 3:21 pm
Dapplegrim wrote:What are the achievements of logic? It would seem to be hard to identify them. ...
The computer you type upon is designed upon it.
Does philosophy need this form of logic? If so what for?

Does anyone have any suggestions?
Reasoning.
The computer uses the logic of mathematics not the so called 'laws of logic'.

I am not at all sure that reasoning actually requires a formalisation of logic in the form of the 'laws of logic'

Which brings us to the question: 'What is logic?'

My argument:

Order through symmetry, with symmetry itself being composed of:

1) Constant mirroring symmetries in which one dimension mediates into another dimension as extension of the previous one making it ever present.

2) Continual relating units whose individuation (seperation) in turn relates to a further unit resulting in a change that propogates the units. In simpler terms relation.

3) Synthesis of dimensions that provide both the foundation for consistency and change, while being neither. In simper terms, 1/3 of logic is dependent upon a process of synthesis.

Arising_uk
Posts: 11773
Joined: Wed Oct 17, 2007 2:31 am

### Re: What are the achievements of Logic?

A_Seagull wrote:The computer uses the logic of mathematics not the so called 'laws of logic'.
Depends how you understand the history of Computing, Boolean Logic is very useful combined with Binary mathematics hence computers are implemented with logical gates.
I am not at all sure that reasoning actually requires a formalisation of logic in the form of the 'laws of logic'
Speaking a language doesn't require the knowledge of the rules of grammar but they still apply. The point of learning Logic in Philosophy is that it sharpens the mind which is helpful when following a chain of reasoning and discovering any logical errors.
Which brings us to the question: 'What is logic?'
Depends upon the context I'd say but philosophically it's the laws of Reason.

A_Seagull
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### Re: What are the achievements of Logic?

Arising_uk wrote:
Tue Jan 30, 2018 12:15 am
The point of learning Logic in Philosophy is that it sharpens the mind which is helpful when following a chain of reasoning and discovering any logical errors.
How would you know?
Which brings us to the question: 'What is logic?'
Depends upon the context I'd say but philosophically it's the laws of Reason.
Logic isn't laws! Logic is a process of inference that follow axioms.

Necromancer
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### Re: What are the achievements of Logic?

A_Seagull wrote:
Mon Jan 29, 2018 10:13 pm
Arising_uk wrote:
Mon Jan 29, 2018 3:21 pm
Dapplegrim wrote:What are the achievements of logic? It would seem to be hard to identify them. ...
The computer you type upon is designed upon it.
Does philosophy need this form of logic? If so what for?

Does anyone have any suggestions?
Reasoning.
The computer uses the logic of mathematics not the so called 'laws of logic'.

I am not at all sure that reasoning actually requires a formalisation of logic in the form of the 'laws of logic'

Which brings us to the question: 'What is logic?'
I disagree. How do you express the OR-port in math? There must be logical ports in computing!

Arising_uk
Posts: 11773
Joined: Wed Oct 17, 2007 2:31 am

### Re: What are the achievements of Logic?

A_Seagull wrote:How would you know?
In what sense? If you mean what do I base my opinion on it'll be having studied Philosophy and Logic and my experience of the world.
Logic isn't laws! Logic is a process of inference that follow axioms.
'Lawlike' if you prefer, of course you could prove me wrong and demonstrate how a thing can be and not be at the same time?

A_Seagull
Posts: 860
Joined: Thu Jun 05, 2014 11:09 pm

### Re: What are the achievements of Logic?

Arising_uk wrote:
Tue Jan 30, 2018 2:52 pm
A_Seagull wrote:Logic isn't laws! Logic is a process of inference that follow axioms.
'Lawlike' if you prefer, of course you could prove me wrong and demonstrate how a thing can be and not be at the same time?
What is meant by a 'thing'? Is it:
- A string of alpha numeric characters?
- A label for a concept?
- a reference to a noumenon?
It is rather ambiguous.

And what is meant by 'be' and 'not be'?

And how is it possible to determine whether 'be' or 'not be' is applicable?

Presumably to merely claim that something 'be or not be' is entirely meaningless?

surreptitious57
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Joined: Fri Oct 25, 2013 6:09 am

### Re: What are the achievements of Logic?

Necromancer wrote:
Math is math and logic is logic for very good reasons They really do not go together
Not true because math is a subset of logic and so actually they really do go together

Arising_uk
Posts: 11773
Joined: Wed Oct 17, 2007 2:31 am

### Re: What are the achievements of Logic?

A_Seagull wrote:What is meant by a 'thing'? Is it:
- A string of alpha numeric characters?
- A label for a concept?
- a reference to a noumenon?
It is rather ambiguous. ...
Really? You don't know what a thing is? Okay, an object or all those things in that external world you live in, better?
And what is meant by 'be' and 'not be'?
Try 'exists' then.
And how is it possible to determine whether 'be' or 'not be' is applicable?
Not 'be or not be' but 'be and not be'.
Presumably to merely claim that something 'be or not be' is entirely meaningless?
Well something is or it isn't makes some kind of sense I think but try it with an 'and'.

A_Seagull
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Joined: Thu Jun 05, 2014 11:09 pm

### Re: What are the achievements of Logic?

Arising_uk wrote:
Sun Feb 04, 2018 12:58 pm
A_Seagull wrote:What is meant by a 'thing'? Is it:
- A string of alpha numeric characters?
- A label for a concept?
- a reference to a noumenon?
It is rather ambiguous. ...
Really? You don't know what a thing is? Okay, an object or all those things in that external world you live in, better?
And what is meant by 'be' and 'not be'?
Try 'exists' then.
And how is it possible to determine whether 'be' or 'not be' is applicable?
Not 'be or not be' but 'be and not be'.
Presumably to merely claim that something 'be or not be' is entirely meaningless?
Well something is or it isn't makes some kind of sense I think but try it with an 'and'.
I think you are missing the point.

If one is going to apply rigorous logic to a statement then the elements of that statement need to be rigorously defined. If they are not, then proper logic cannot be applied and all that one is left with is a sort of hand-waving argument and a claim that this is 'obvious' or perhaps 'normative'. But that is not logic.

wtf
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### Re: What are the achievements of Logic?

surreptitious57 wrote:
Sun Feb 04, 2018 7:41 am

Not true because math is a subset of logic ...
Yet another one who missed Gödel's 1931 memo.

Atla
Posts: 1804
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### Re: What are the achievements of Logic?

Logic is something like: how concepts relate to each other.

Boolean / left hemisphere / yes-or-no logic is super useful in pretty much all areas of life. Fuzzy / right hemisphere / probabilistic logic is super useful in most areas of life.

I've found that in the end, human understanding really is circular though. So a complete description of reality will always have to use circular logic. Use boolean where you can, fill the rest using fuzzy.

Arising_uk
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Joined: Wed Oct 17, 2007 2:31 am

### Re: What are the achievements of Logic?

A_Seagull wrote:...
If one is going to apply rigorous logic to a statement then the elements of that statement need to be rigorously defined. If they are not, then proper logic cannot be applied and all that one is left with is a sort of hand-waving argument and a claim that this is 'obvious' or perhaps 'normative'. But that is not logic.
Given that rigorous Logic applies to variable symbols that stand for any proposition what is to be defined in the elements of the statement that they stand for?

Londoner
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### Re: What are the achievements of Logic?

Arising_uk wrote:
Mon Feb 05, 2018 12:24 pm
Given that rigorous Logic applies to variable symbols that stand for any proposition what is to be defined in the elements of the statement that they stand for?
Those propositions only have the property of being true of false. They also have to be distinct from the connectives, so they cannot themselves contain or refer to bits of logic.

Any particular proposition is going to refer to a 'something', but a 'something' is not simply true or false. If 'X' stood for 'Man'', we cannot ask ''Man': true or false?' The answer would depend on notions of language, what was meant by the assertion and so on. So that 'X' would not be simple, it would hang on a whole series of other propositions and logical relations.

One idea was that the meaning of 'Man' and everything else is ultimately built up from a series of sense impressions, so that if we fully worked out what was intended we could form propositions from very simple experiences; 'Red-ness!' , 'Hardness!' etc. which would either be there or they wouldn't, so either true or false. But the problem was that as soon as we expressed sense impressions in language they were no longer simple. For example, the word 'red-ness' cannot be understood except by also understanding 'not-green-ness'.

So we have the peculiar situation that logic works with 'any proposition' - but not with any specific proposition!

(This stuff is from Wittgenstein)

A_Seagull
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Joined: Thu Jun 05, 2014 11:09 pm

### Re: What are the achievements of Logic?

Arising_uk wrote:
Mon Feb 05, 2018 12:24 pm
A_Seagull wrote:...
If one is going to apply rigorous logic to a statement then the elements of that statement need to be rigorously defined. If they are not, then proper logic cannot be applied and all that one is left with is a sort of hand-waving argument and a claim that this is 'obvious' or perhaps 'normative'. But that is not logic.
Given that rigorous Logic applies to variable symbols that stand for any proposition what is to be defined in the elements of the statement that they stand for?
It is possible apply a mapping between formal logic and arbitrary statements and conditionals. And this may well be useful for solving puzzles based on a quasi-reality.
But such a mapping hasa not shown itself to be useful in the domain of real philosophy and so can be ignored or dismissed. In fact it should be ignored as it can lead to the illusion of certainty, which while acceptable for an individual has no place in philosophy where it can be regarded as a delusion. And delusions need to be avoided in philosophy.

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