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# Why is Logic Logical? Tweet

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1. Why is Logic Logical?
Hello every one!

Why the logical laws are always right,what make the logical laws to be like this ?
2. Re: Why is Logic Logical?
I'm sorely tempted to reply with reference to the law of identity, but I fear I'd be missing the point somewhat.
3. Surely it's a self evident point that such laws maintain by definition, do you mean you think God was the creator of such law?

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4. Re: Why is Logic Logical?
Reading the question as 'what justifies what we consider to be logical laws', we don't have that much of an answer; generally the answer tends to run that logical laws are the only way we have to think: any others would give us valid arguments that we wouldn't regard as valid, and wouldn't show the arguements we regard as valid to be such. So we have to take them as a result of a process of bringing into conformity with what we accept as our reasoning.

Having said that there are other 'versions' of logic that come up in some cases; intuitionist logic rejects the idea that propositions are true or false without being provable, you can consider quantum mechanics and get funky quantum logic with weird effects, you can try to account for vagueness with fuzzy logics and so on. But they tend to agree on a lot as well.

It's a good question though, it was the topic for my IB extended essay.
5. Re: Why is Logic Logical?
(Original post by MAA_96)
Hello every one!

Why the logical laws are always right,what make the logical laws to be like this ?
This is a circular question, rather like asking "why is maths mathematical?" Logic is an internally consistent system which based on certain tautological axioms. It only 'works' because we think it does.
6. Re: Why is Logic Logical?
(Original post by dbmag9)
Having said that there are other 'versions' of logic that come up in some cases; intuitionist logic rejects the idea that propositions are true or false without being provable, you can consider quantum mechanics and get funky quantum logic with weird effects, you can try to account for vagueness with fuzzy logics and so on. But they tend to agree on a lot as well.
Precisely, what we call "logic" is just a bunch of inference axioms a bunch of people have agreed to, and they are not the only such possible axioms.

On a side note, even though it's funny, please don't use "logical" as meaning right like Spock fallaciously does. "Logical" means that it follows from the inference axioms; this does not take into account, in any way, the premises you used those axioms on. So, for example, "If all humans were purple, and Socrates was human, then Socrates was purple" is logical.
7. Wikipedia logic. OMG the description for it is amazing

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8. Re: Why is Logic Logical?
(Original post by xiyangliu)
Wikipedia logic. OMG the description for it is amazing

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... you mean the line "Logic is the study of valid reasoning"?
9. Re: Why is Logic Logical?
Because otherwise they'd be illogical.
10. Re: Why is Logic Logical?
Why is logic logical?

11. Re: Why is Logic Logical?
If something is logical it's existence is because of a series of deductions. Take the following example:

Female, human children are called girls.
My little sister Bessie is both a female and a child.

Since those that match those two criteria are called girls, my little sister Bessie is a girl.

Logic is just a process, it's nothing tangible or existent, it's simply a human definition of why stuff works.
12. Re: Why is Logic Logical?
@Birdsong1 made a really good comment.

So there are some things that should be separated.

1. The everyday use of what people mean to be logical is really ambiguous, and to some extent I think it's unhelpful. 'Logical' means all kinds of things from 'the conclusion follows from what is earlier said', or simply a synonym for 'reasonable' or true.

Philosophical logic is about the fundamental terms that we use in thought and language, and it's not right to say that there is one 'logic', but there are actually many different systems and they all do different kinds of things. Some logics deal with tense like past tense, future tense. Other logics deal with changing conditions, and the one most people think of is classical logic which considers truth and falsity as its main values.

2. What is mean by logical laws? That's a good question, and just stated we can presume whatever we think of it, and someone else might have a totally different idea. It's better to define this rigorously so even if we disagree, at least we know the object of our disagreement. Some people think that logical laws involve things like 'a double negative is a positive' (double negation elimination), although one form of logic denies this! Some logical laws need to be proven and to do this can involve some high power mathematics. It's fiar to say though, that not everything is set in stone when it comes to logic as logicians and mathematicians understand it. It depends on axioms, defintiions, and also, what we want out of our system.

Anyone who wants to understand this further or talk about it feel free to message me. I hope this was written in an understandable way, this issue is really interesting and so easy to mock.
13. Re: Why is Logic Logical?
Logic is biased because the choice of which question to ask is still biased.

'the colour red + the colour yellow = the colour orange'

Yes but why not choose to say 'the colour orange + the colour orange = the colour orange' instead?

The addition demands an answer but it doesn't address whether the colour red was a worthy subject of the question in the first place. It is intrinsically moral relativist really. 'Logic' allows people to justify 'bad' things by ignoring other logical questions that might be asked.
14. Re: Why is Logic Logical?
you're asking why something that is, is?

there's no question here.
Last edited by SnoochToTheBooch; 30-06-2012 at 16:09.
15. Re: Why is Logic Logical?
(Original post by A Mysterious Lord)
Because otherwise they'd be illogical.

(sorry, couldn't help myself )
16. Re: Why is Logic Logical?
The question in the title is completely different to the one in the OP
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