Discussion of what logic is and is not?


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Profile Sarge
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Message 1356334 - Posted: 12 Apr 2013, 20:43:07 UTC

Shall we discuss?

Profile Chris SProject donor
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Message 1356337 - Posted: 12 Apr 2013, 20:45:19 UTC

Logically we shouldn't.

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Message 1356338 - Posted: 12 Apr 2013, 20:49:29 UTC - in response to Message 1356337.

Logically we shouldn't.

I disagree and I meant the question seriously as it came up in the last 24 hours, plus it has come up time and time again, even before there were Political and Non-SETI Science fora.

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Message 1356344 - Posted: 12 Apr 2013, 20:57:10 UTC

are you asking to discuss what is logic?
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Message 1356382 - Posted: 12 Apr 2013, 22:13:23 UTC - in response to Message 1356338.

Sarge Logic is a Vulcan called Spook
live long and prosper
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Message 1356407 - Posted: 12 Apr 2013, 23:56:14 UTC - in response to Message 1356382.

Sorry Sarge but you did leave yourself wide open for that one
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Message 1356419 - Posted: 13 Apr 2013, 1:15:03 UTC - in response to Message 1356407.

Sorry Sarge but you did leave yourself wide open for that one

You were following the other thread.
Do not STIR in here.
Let the serious discussion begin.

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Message 1356426 - Posted: 13 Apr 2013, 1:35:08 UTC - in response to Message 1356419.

Glad you got a sence of humour I will do as you ask and be a good boy
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Message 1356429 - Posted: 13 Apr 2013, 1:50:18 UTC - in response to Message 1356344.
Last modified: 13 Apr 2013, 1:52:59 UTC

are you asking to discuss what is logic?

We either do, or we we don't :)
[edit] On serious note, logic has got us were we are. This works/this doesn't and so on.[/edit]
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Message 1356439 - Posted: 13 Apr 2013, 3:13:25 UTC - in response to Message 1356344.

are you asking to discuss what is logic?


no xor no

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Message 1356443 - Posted: 13 Apr 2013, 3:34:53 UTC

Watson ?
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Profile Chris SProject donor
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Message 1356516 - Posted: 13 Apr 2013, 10:09:19 UTC

C'mon guys, Sarge will get cross in a minute!

"Logic is considering various parameters, and using rational thought processes, coming to a considered conclusion". Will that do for starters?

But I'll chuck a spanner in the works - If certain scientists hadn't thought "outside the box" we wouldn't have discovered some of the breakthroughs that we have done. So secondary question - what about fuzzy logic and Chaos Theory? is plain logic always the best thing?

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Message 1356529 - Posted: 13 Apr 2013, 10:44:24 UTC

Logic is based on assumtions , So if somebody tells you it's logical look for the hidden assumtions
And Chris is right sarge will get cross
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Message 1356549 - Posted: 13 Apr 2013, 11:30:12 UTC

An assumption is something taken for granted or accepted as true without proof; a supposition:

Logic deals in known facts.

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Message 1356570 - Posted: 13 Apr 2013, 14:36:52 UTC

Chris I will tell my friend Patrick you answer to his statement about logic being based on assumptions I said I would post it and tell him what people say

Mind you he has a hard time understanding a lot of things
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Message 1356662 - Posted: 13 Apr 2013, 22:24:59 UTC

I should not have to write a grand opening to get a ball rolling. You all know what was being discussed in recent threads and how this serves as a point to jump in a different, though related, direction. Instead, a number of times, when I have opened a thread, without writing a grand opening, people jump in with wiseguy comments. When my own thread is clearly parody, or someone else's is, this is not surprising. When the intent is clearly serious, the wiseguy comments are not appreciated. In my next post, I will introduce the impetus for this thread, which people should have known, as they read/posted in recent related threads. I thank the mods in advance for acting on the red Xs I sent last night regarding off-topic posts.

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Message 1356664 - Posted: 13 Apr 2013, 22:37:32 UTC
Last modified: 13 Apr 2013, 22:44:04 UTC

I.D., the poster, recently claimed Logic is a science.
I said I disagreed. I said if it was, point me to a recent new theorem, or experimental finding, from logic. (It will have to be about logic.)
Of course, I.D. disagreed, but did not answer my points or say anything else I could find reasonable, whether due to his posting style or understanding or whatever.
Mr. Kevvy accused I.D. of having an understanding of logic that is 2000 years (or more) old.
But I did not find Mr. Kevvy's elaboration particularly satisfactory. It was primarily him I was inviting ... as the original invitation to discuss is ... well, you know ... though through know fault of my own that I know. All parts of that other discussion are ... well, you know.
Mr. Kevvy may have been trying to be brief. He may have been trying to address the response to I.D. on I.D.'s level. I would like to know what he and others think logic is, how it compares to my own understanding, and to either educate or be educated myself, at least a bit.
There are things I posted about logic 6-7 year ago on these fora. I took more time then. I did a better job at making my points. (Whether I swayed anyone is another matter.)
I shall begin by saying that it is not just assumptions. Logic includes undefined terms, axioms (or postulates; i.e., unproven statements. A.K.A., the assumptions.) The number of these first two are kept small. Consistency, among other things, is required. Then we have the defined terms. From there, Logic is a TOOL for mathematics and the sciences (not a science itself as far as I can remember/see-refer to the second paragraph). The tool of logic, is to prove or disprove other statements.
Why Mr. Kevvy thinks this is separate for the experimentalists he mentioned, of classical Greece, I do not know. Perhaps they viewed it this way back then. Today, the two are most definitely NOT separate. To determine whether an experiment has produced significant results, there are specific methods, and these methods rest on logic.
With this said ... it is now Mr. Kevvy's turn or that of others who wish to join in a serious conversation.

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Message 1356667 - Posted: 13 Apr 2013, 22:53:24 UTC

Logic is a thought process by which conclusions are made, based first on known provable facts and then supported by assumptions that are most likely to be true. Also logic depends on being able to rule out conclusions that would result in contradictions to known facts.
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Message 1356670 - Posted: 13 Apr 2013, 23:01:36 UTC

Sarge my friend made simular points to you , about logic being based on assumptions it sounded dare I say it Logical when he was trying to explain it to me and why I agreed to put it up in your post .He used the argument that theretical scince hasn't been proven so is made of assumptions .So maybe he's right ,he sometime seems to make cents
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Message 1356688 - Posted: 14 Apr 2013, 0:46:18 UTC - in response to Message 1356667.

Logic is a thought process by which conclusions are made, based first on known provable facts and then supported by assumptions that are most likely to be true. Also logic depends on being able to rule out conclusions that would result in contradictions to known facts.


No, known provable facts comes after the assumptions. (Furthermore, we don't always know what facts we'll end up proving.)

I made this post "Last modified: 4 Oct 2006, 20:42:05 UTC"

What Euclid put forth as an axiomatic system, and what was accepted for several centuries, is now seen to be flawed. In the late 19th and early 20th centuries, people such as David Hilbert tightened things up again. The current view is that an axiomatic system is:

1) A set of undefined terms. (This avoids circularity. Look at a dictionary, and every word they choose to include --- deemed to be socially accepted as a word --- is defined in terms of other words. Look up these words, and they again are defined in terms of other words. Expand the search far enough, and you'll likely come back to the word you started with.) The set of undefined terms should be kept small.
2) The set of defined terms.
3) The set of axioms. This set should also be kept small. (* I shall return to the discussion of axioms momentarily.)
4) Theorems, if-then statements built up through reasoning/proof.

From Euclid until Hilbert, axioms were statements taken to be true without proof. These statements were viewed as "self-evident." Interesting? The current approach to axioms is that there does not need to be any self-evidence. The axioms may even be about mathematical structures for which there is no currently known way to view them in the ways we perceive the universe, so how can we talk about them being self-evident? However, the axiomatic system must be consistent. It cannot lead to two if-then statements later on which contradict each other.
Most importantly, so long as these and perhaps a few other requirements are met, axioms are essentially taken on faith. A "group" is defined as a set where any two elements of the set can be combined by an operation. Every such combination under the operation results in another element of the set. (When I say another, this does not have to mean different.) The operation is associative and, with respect to the operation, there is a (unique) identity element and every element has a(n) (unique) inverse.
The concept of a group historically came about from recognizing similarities between the addition operation on the set of real numbers, the multiplication operation on the set of real numbers without the 0 element, and several other sets with an operation as I have described. Mathematicians abstracted the ideas, boiled it down to "these are the basics, the minimal set of things, we need to discuss something of interest." The concept was at some point agreed upon through social agreements and formalized.
Since then, we don't question the axioms. We take them on faith and simply consider what things we can show as a consequence of what we have set forth.

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