Reason and Logic

[forrestcupp]

Since people here are quick to correct others who incorrectly use the term "logic", let's have a thread to talk about it.

What is the difference between reason and logic? Now is your chance to not just correct everyone, but to teach us why you're correcting them.

[Shibblet]

I don't think it's about correction.

Most people ask questions that do not pertain to the issue or problem. The most difficult portion of the "return question" is determining what the original problem is. That's why when you ask a question about how something works in Ubuntu, your response is usually another question.

It's a process of troubleshooting. Once we (helpers) determine what the issue is, we can offer our opinion about the best way to resolve it.

For example: My mother had an issue with Evolution the other day. It wouldn't put the proper signature line on her outgoing emails. So I took a look at the issue, and it was not saving her results. I decided to download Thunderbird to see if it would, and it did. So, the solution was: Don't use Evolution, use Thunderbird.

Was that a solution or a workaround? Who knows, but it solved her problem. She likes T-Bird better anyway.

So, to answer your question, Logic is basic mathematics in situations. Situation A - Situation B = Fixed. Reason is how to set up the formula.

[gsmanners]

Logic (http://en.wikipedia.org/wiki/Logic) has rules, and reason (http://en.wikipedia.org/wiki/Reason) imposes those rules, but not necessarily those particular rules. You can't have logic without reason, but nothing in reason dictates logic. A person can be perfectly reasonable without being logical.

see: http://en.wikipedia.org/wiki/Reason#Reason_compared_to_logic

[Bandit]

A reason is a consideration which explains or justifies some event.

Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is often divided into two parts, inductive reasoning and deductive reasoning.

Inductive Reasoning is commonly construed as a form of reasoning that makes generalizations based on individual instances.

Deductive Reasoning are deductive arguments that are attempts to show that a conclusion necessarily follows from a set of premises or hypotheses.



Great now I sound like an educated idiot for giving a dictionary answer and no persuasive argument behind it. :frown:

[Shibblet]

Reason dictates that someone ate the cookie.

Logic determines who it was.

[krapp]

Reason is the capacity for rationality, logic the deployment of that rationality, often in identifiable forms. It doesn't go further than that without veering into heavy ideology.

[forrestcupp]

How about some real world examples?

[red_Marvin]

Logic is a special branch of math, or math is a very zoomed out version of logic.
Reason is trying to take these these ideal-world rules and applying
them on the real world, where we do not only have mathematical
axioms etc. but also notions of good and bad and the like.

Logic:
If you steal -> You are bad.
If you help the poor survive -> You are good.

Reasoning comes in when you try to decide wether or not Robin Hood
was good.

[hhh]

Ugh, a semantic arguement about related nouns with multiple definitions? Shall we add rational to the mix? First one to break out Gödel, Escher, Bach wins!

How about a link to threads where someone is arguing the term's usage?

[forrestcupp]

How about a link to threads where someone is arguing the term's usage?

It's been a while, so I probably couldn't find them (or I don't care to waste my time trying :) ). It's just something that's stuck with me, and if people really care about it, I'd like to understand it.

[hhh]

Logic is a tool of reasoning.

Reason, logic, fallacy, argument, assertion, deduction, syllogism, rhetoric, belief, truth, reality... do you realize how big a can of worms you're opening here? I'm not a philosopher, so take a look at this for starters...
http://plato.stanford.edu/entries/aristotle-logic/

I'm going to guess that the arguments you saw in the forums were trying to point out logical fallacies, of which there are many, many types...
http://en.wikipedia.org/wiki/List_of_fallacies
... but which are different from simply being wrong about the facts. Of course if your facts are wrong you will have a wrong conclusion. However,
(t)he validity of an argument depends... not on the actual truth or falsity of its premises and conclusions, but solely on whether or not the argument has a valid logical form. The validity of an argument is not a guarantee of the truth of its conclusion. A valid argument may have false premises and a false conclusion...
Some Greeks are logicians and some logicians are tiresome; therefore, some Greeks are tiresome. Invalid argument: the tiresome logicians might all be Romans (for example).
So the logic is correct but the premises are unreasonable (I think I'm stating that right).

Logic is a dying thing. How many fallacious arguments do we hear every day, from politicians for example?...
http://open.salon.com/blog/emagill/2010/04/09/top_10_logical_fallacies_in_politics

I don't think the Robin Hood example is very good because that's bringing morality and ethics into it (and you can have a big philisophical debate over those terms too). Why is it wrong to steal? Are there no circumstances where it might be right to steal?

I found some famous quotes regarding reason and logic, here are my two favorites...
No, no, you're not thinking; you're just being logical.

If the world were a logical place, men would ride side saddle.

I've really enjoyed researching my posts in this and the Paul thread, Forrest. Thanks!

[Copper Bezel]

Yeah, offhand, I would have put the difference at being the difference between validity and cogency, and I don't think that's too pedantic or arcane to be reflected in common usage; we can say that a thing is the logical conclusion of an unreasonable line of thinking.

[hhh]

Examples, looks intimidating but it's a quick read...

Logic...
Logic is the study of correct reasoning...Logic is not the study of how people do reason, but how they should reason. We might put this point differently by saying that logic does not describe the psychology of reasoning, with its flashes of insight and oversight; it prescribes methods of justifying reasoning, that is, for showing that a given bit of reasoning is proper.

An example of such logical reasoning (deductive logic) is:

All cows are purple.
Wilma is a cow.
Therefore, Wilma is purple.

Note that the argument is true regardless of the truth of the two premises.
^Sound inference, useless conclusion.
Source- http://perspicuity.net/common/logic.html

BUT...

Reason...
Human experts often feel in practicing their domains of expertise that they follow the model of reasoning used in formal logic: from correct premises, sound inference rules produce new, guaranteed correct conclusions. On reflection however, we realize there are many situations that will not fit this approach; that is, we must draw useful conclusions from poorly formed and uncertain evidence using unsound inference rules.

Drawing useful conclusions from incomplete and imprecise data with unsound reasoning is not an impossible task; we do it very successfully in almost every aspect of our daily life. We deliver correct medical diagnoses and recommend treatment from ambiguous symptoms; we analyze problems with our cars or stereos; we comprehend language statements that are often ambiguous or incomplete; and we successfully navigate the stock and money markets.

...if the engine does not turn over, and the lights do not come on then the problem is battery or cables.

On the surface, this rule looks like a normal predicate relation to be used in sound inferencing (modus ponens). However, it is not; it is heuristic in nature. It could be possible, though very unlikely, that the battery and cables are fine but that the car simply has a bad starter motor and burned-out headlights...
^Unsound inference, useful conclusion.
Source- http://www.econ.uba.ar/servicios/publicaciones/journal1/contents/luger.htm

Finally...
All monkeys have blue teeth
Meg is a monkey
Therefore, Meg has blue teeth

Notice that in this example, the premises and conclusion are all false. Yet the argument is still valid because IF the premises were true, the conclusion would have to be true as well. A valid argument is important because it tells us that the form is A-OK, yet if we find out that all the premises are true, then the truth of the conclusion is guaranteed. So what happens when the premises of a valid argument are in fact true? We call a valid argument with true premises a sound argument...

Validity + True Premises = Soundness
Source- http://www.unc.edu/~megw/Logic.html

[ikt]

Logic is a dying thing.

mmm?

Was it ever alive to begin with?

[Gremlinzzz]

[Think different]
ain't possible
[Think out of the box]
that line put me in a box.
logic doesn't need a reason its just logical!

[forrestcupp]

I'm going to guess that the arguments you saw in the forums were trying to point out logical fallacies, of which there are many, many types...There weren't any arguments. It wasn't an argument between two knowledgeable people about logic. Basically, it went something like this. Someone made a comment that made a lot of sense. Someone said that was logical. Someone else who knows a lot came riding in to correct the person, letting them know that they misused the word "logical" and they really meant "reasonable". There was never a teaching on why the word "logical" is wrong, and why we should be using the word "reasonable". I've been on these forums for a long time, and I've seen it happen many times.


Examples, looks intimidating but it's a quick read...
Are you saying that logic can be right in form but still false, but reason is always true? If that's the case, then it seems like some logic is reasonable, but all reason uses logic.

[hhh]

Sorry, I was house sitting the last few days. That sounds like someone being overly pedantic since logical and reasonable are synonyms.


Are you saying that logic can be right in form but still false, but reason is always true? If that's the case, then it seems like some logic is reasonable, but all reason uses logic.
No, of course reason isn't always true. What I think the posts I linked to are saying is that logic is a formulaic way to reason, and if all the facts in the formula are true then your reasoning will be true. The problem is that we usually don't have all the facts and so have to add intuition to our reasoning (it's not logical that the battery is dead as it could be blown out headlights, but trial and error has shown that it's reasonable).

All reasoning uses logic? I think not... "My feet are killing me." "Why are you wearing heels?" "They make my legs look great!"

If reasoning is always true then the world is either flat or it's turtles all the way down.

[itguy1985]

They are so similar; I can't think of any examples that would separate the two. I think logic is more the process that leads to reasoning.

[drawkcab]

Logic is simply inquiry into inquiry, or reasoning about reason if you like. In other words it is the attempt to articulate the norms of inference that condition the path from doubt to belief.

[forrestcupp]

I'm starting to see it.

Here is a general example of what I'm talking about (http://ubuntuforums.org/showpost.php?p=10586712&postcount=81) in the words that drive you nuts thread.


'Logical' is another one, as in 'it's logical'. Everytime I've heard people say this they mean 'It makes some kind of sense' or 'It's reasonable'.
A few people agreed. I just invited them to come to this thread and explain it for us.

[forrestcupp]

All reasoning uses logic? I think not... "My feet are killing me." "Why are you wearing heels?" "They make my legs look great!"


But it seems like that is logic, just horrible logic.

[cespinal]

brb - wikipedia

[satanselbow]

Great now I sound like an educated idiot for giving a dictionary answer and no persuasive argument behind it. :frown:

A both reasonable and logical conclusion ;)

[Grenage]

But it seems like that is logic, just horrible logic.

Indeed a logic of sorts. In such an example the reasoning would have to factor in the logic of personal priorities; that's a path that takes a simple question of logic, and moves into a sociological minefield.

Reasoning encompasses logic, but the logic used is usually open to speculation. Half of the time people speak from their gut, which undoubtedly comes from subconscious logic.

[forrestcupp]

Reasoning encompasses logic, but the logic used is usually open to speculation. Half of the time people speak from their gut, which undoubtedly comes from subconscious logic.

That's what I'm saying. It seems like all reasoning uses some kind of logic even if the person doesn't realize they're going through logical steps to get there. If they didn't at least subconsciously use logic to come up with their solution, then it's not really reasoning; it's just an idea.

If that is the case, then why would it ever be wrong to use the word "logical" instead of "reasonable"? You don't have to always explain your logical steps for something to be logical.

[Grenage]

If that is the case, then why would it ever be wrong to use the word "logical" instead of "reasonable"? You don't have to always explain your logical steps for something to be logical.

I don't think it would be wrong; personally when speaking to others I would limit my use of the logic to refer to a common logic, leaving my use of the word reasonable to refer to a more general or personal logic. If A=1+C, then logically A is always bigger than C; if a burglar attacks you, it is reasonable to defend yourself.

I can't imagine berating someone for using logical instead of reasonable.

[forrestcupp]

I can't imagine berating someone for using logical instead of reasonable.

Well, I linked to an example in post #20, and that is definitely not the only time it's happened in these forums. That's why I started this thread. Honestly, I don't care if people don't like how I use the word "logical". But I am kind of interested in why.

You gave some good examples of a good rule to follow. I appreciate everyone's input. Please continue to add your thoughts so I can continue to get this sorted out.

And just for the record, I don't remember anyone actually berating me for the improper use of the word "logical". I've just seen it, and when I see people correcting others for something that happens frequently, I like to understand why.

[Grenage]

Well, I linked to an example in post #20, and that is definitely not the only time it's happened in these forums. That's why I started this thread. Honestly, I don't care if people don't like how I use the word "logical". But I am kind of interested in why.

From the post you linked:


Refute'. 99% of the time people mean 'retort'.

I've got to be honest, I've never once heard someone say refute, when they actually meant retort. I have however heard a thousand people say i could care less when they meant I couldn't care less, or that someone was literally mental, when they clearly were not.

Considering that one of the dictionary definitions for logic is now "capable of or characterized by clear or valid reasoning", it is not not incorrect; perhaps not to one's tastes, but not simply wrong.

[Throne777]

Since people here are quick to correct others who incorrectly use the term "logic", let's have a thread to talk about it.

What is the difference between reason and logic? Now is your chance to not just correct everyone, but to teach us why you're correcting them.

Logic is systematized reasoning. Classical logic, for instance, is an axiomatic system that guarantees truth preservation (it's unclear whether induction has a logic -classically, induction is just a non sequitur).

So, you might think that if you do 1,000 experiments on the boiling point of water, and every single time you get the result 100 degrees, then you've proven that the boiling point of water is 100 degrees. Logically, this doesn't follow at all. There is nothing, logically, to stop the 1,001th (and every subsequent) experiment having water come out as boiling at 1,000,000 degrees. So yes, scientific reasoning is largely illogical.

Classical logic also has some slightly odd characteristics if you apply it to the English language (it's not obvious that English has a logical form). As an example,

"If homer has a blue head, then grass is purple and everyone can fly' (P -> (Q & Y)) is true, for instance. Why? Because if both the antecedent and consequent are false, the conditional comes out as true. Or, if the consequent is true, then no matter what the antecedent is, the conditional is true. So, 'If God can make a rainbow out of puppies, then snow is white' is true.

Another thing a lot of people find odd is that a disjunction is true if BOTH conjuncts are true (obviously, if one conjunct is true, the disjunction comes out as true). So, if you say 'What's Bob up to?' and I say 'He's playing with a yo-yo or listening to music'. If it turns out he's doing both, then what I said is true. Sounds a little odd, you might think what I said was false, because using 'or' seems to imply that he was doing one or the other but not both; not so in logic.

[Throne777]

I don't think it would be wrong; personally when speaking to others I would limit my use of the logic to refer to a common logic, leaving my use of the word reasonable to refer to a more general or personal logic. If A=1+C, then logically A is always bigger than C; if a burglar attacks you, it is reasonable to defend yourself.

I can't imagine berating someone for using logical instead of reasonable.

That's not logic.

[Grenage]

There is nothing, logically, to stop the 1,001th (and every subsequent) experiment having water come out as boiling at 1,000,000 degrees. So yes, scientific reasoning is largely illogical.

That come under probability and theory. Logic would be applied to the test and would allow for interpretation of the results.


That's not logic.

The dictionary says you're wrong, and so do I. You're not defining forms.

[Throne777]

That come under probability and theory. Logic would be applied to the test and would allow for interpretation of the results.

The dictionary says you're wrong, and so do I. You're not defining forms.

The dictionary also says that the definition of 'cause' is:

"1.
a person or thing that acts, happens, or exists in such a way that some specific thing happens as a result; the producer of an effect: You have been the cause of much anxiety. what was the cause of the accident?
2.
the reason or motive for some human action: The good news was a cause for rejoicing."

Try telling that to a bunch of philosophers interested in etiology or action.

Or how about the definition of 'mind':
"The element of a person that enables them to be aware of the world and their experiences, to think, and to feel; the faculty of consciousness and thought"

Try putting that forward as a refutation of functionalism. 'The dictionary says you're wrong!'

Believe it or not, the OED does not settle philosophical & mathematical debates.

To address your other points:
Game theory isn't logic. It's a theory of reasoning about statistical probabilities. 'Choose the likeliest outcome' or 'Choose the option that gives you the optimal results' (etc) AREN'T logical truths.

[Grenage]

The dictionary also says that the definition of 'cause' is:

"1.
a person or thing that acts, happens, or exists in such a way that some specific thing happens as a result; the producer of an effect: You have been the cause of much anxiety. what was the cause of the accident?
2.
the reason or motive for some human action: The good news was a cause for rejoicing."

Try telling that to a bunch of philosophers interested in etiology or action.

Or how about the definition of 'mind':
"The element of a person that enables them to be aware of the world and their experiences, to think, and to feel; the faculty of consciousness and thought"

Try putting that forward as a refutation of functionalism. 'The dictionary says you're wrong!'

Believe it or not, the OED does not settle philosophical & mathematical debates.

Lol; you are of course correct, but this is not a mathematical or philosophical forum. Most people here are (probably) just your average folk with limited interest in semantics; here I would most definitely use logic and reasoning in their general sense.

[Throne777]

Lol; you are of course correct, but this is not a mathematical or philosophical forum. Most people here are (probably) just your average folk with limited interest in semantics; here I would most definitely use logic and reasoning in their general sense.

I realise that, but then wasn't the point of the thread specifically to dispel the notion that you can use 'logic' & 'logical' in its wishy washy sense?

[Grenage]

I realise that, but then wasn't the point of the thread specifically to dispel the notion that you can use 'logic' & 'logical' in its wishy washy sense?

Yes, I concede that (I'll find the cliff's edge soon). If we delve into all the different forms of logic and reasoning, this will be a rather substantial thread.

[forrestcupp]

That's not logic.

But there are many forms of logic and you're only talking about one of them. That's like telling a chemist that he doesn't know anything about science because he's not into marine biology.

[Throne777]

But there are many forms of logic and you're only talking about one of them. That's like telling a chemist that he doesn't know anything about science because he's not into marine biology.

No, it's more akin to claiming intelligent design is science.

[drawkcab]

http://www.peirce.org/writings/p107.html