中學生齊齊來探討邏輯學

周自横

晚生不才，不過對於邏輯學很有興趣...所以特地開了這個主題來做探討、交流、教學（當然不是晚生來教~！）
繼全中辯之後，針對“組織年輕化 是/不是 鄉團持續發展的先決條件”和“儒家思想具/不具備成爲世界思想的主流”兩題所可能產生的邏輯矛盾，讓我們在這裡做一個探討和交流...彼此互相學習...
不過，礙于邏輯學原本就是很容易讓人感到混亂的項目，希望前輩們能將貼集中（不要連續發太多貼）...除非是内容太過於長的貼或是内容/主題不同的貼...

互相學習，一同成長
謝謝！

周自横

主題一：假言推理（充分、必要、充分必要、先決）

我們假設：
1.   A是因，B是果
2.   有A以外的第二因；既A不是唯一影響B的因，A、B、C...是他因關係

對於充分條件：（A是使B成立的充分條件）--------------------------1
有A必有B；無A未必無B（C、D...使B成立）

對於必要條件：（A是使B成立的必要條件）
有A未必有B（還需要B、C...的存在）；無A必無B---------------------2

1+2得：
有A必有B；無A必無B
       或
有A未必有B（還需要B、C...的存在）；無A未必無B（C、D...使B成立）

由於後者=A與B沒有關係...所以不談。

那麽，“先決”又怎麽解？
根據日不落帝國前輩說的：
一者是詞義定義=>邏輯關係等于“必要條件”；既有A未必有B，無A必無B
一者是邏輯定義=>邏輯關係等于“充分必要條件”；既有A必有B，無A必無B
先來探討這樣的劃分是否合理...
再來探討何者更爲邏輯...

依照字面解釋，先決=先行解決
例：要去旅行，要先行解決的問題是交通工具的問題
如果是詞義定義：解決了=去旅行 或 不旅行（可能有第二因影響）；沒解決=不旅行
如果是邏輯定義：解決了=去旅行；沒解決=不旅行

同樣的例子，用在“充分條件”的判斷上：
解決=去旅行（沒有第二因）
沒解決=去旅行 或 不旅行--------------------------------------成立？

想到這裡，晚生頓時領悟到，關鍵似乎在於---->第二因的存在與否，其關係是共因或他因...
這樣判斷是否有謬誤？還望指教...

周自横

再來擧多一個例子：

‘下雨’是‘地溼’的‘充分’條件：
下雨 溼----------------------------------沒有他因阻止它溼
無雨 溼 或 不溼------------------------他因的存在，所以才有溼的可能

‘下雨’是‘地溼’的‘必要’條件：
下雨 溼 或 不溼----------------------他因的存在，所以才有不溼的可能
無雨 不溼----------------------------------沒有他因讓它溼

‘下雨’是‘地溼’的‘充分必要’條件：
下雨 溼----------------------------------沒有他因阻止它溼
無雨 不溼----------------------------------沒有他因讓它溼
[br][br]-=-=-=-=- 以下内容由 周自横 在 2006年06月09日 03:26pm 时添加 -=-=-=-=-
如果是這樣推下來...
那“先決”的邏輯意義是和“必要”還是“充分必要”有關？爲何？

phua1991

Still want to discuss logic issue. You have a very good attitude  
n_n.

Your 第二因 is a good point.

日不落帝國 definition is mis-understanding. 詞義定義 is if you want B, thus you need to have A first. This is the common way we use the term.
The 新手理论、技巧破解 has a lot of its. Ex: 必要与充分,是什么关系呀 < http://www.taor.net/bianlun/bbs/cgi-bin/topic.cgi?forum=39&topic=1092&show=60 > forum. You will read a very useful article (a little bit difficult to understand without background). Take you time and enjoy it. You properly need to spend the whole holiday.  Hi hi…:p. Try to get someone understands logic or philosophy to explain for you.

After read it, you will understand whatever you agreed or not, you are able to point up a very strong and persuasive reason. That is what I emphasis that you need to prepare.

Quote from SIGN.

“是说那些在场上问对方“今天的正（反）方观点是必要条件还是充分条件”的伎俩。因为这种问题只能说明提问者：
1、表述方式的匮乏；
2、辩论理念的功利性；
3、思维方式的泛科学化——让我想起我的某位教练在他的一篇文章中转引过的一句话（大意）：社会学的论文巴不得自己像经济学论文一样充满符号；而经济学的论文巴不得自己像数学论文一样只有符号。”

At the end,
Logic is the whole of debate, but it is a very useful tool especially in attacking opponent. If opponent attacks you, can you stand on your ground?
The main thing is debater should not panic when opponent attack your logic.
Another weakness in young debater is they always like to use logical term, BUT use it in WRONG WAY.

[br][br]-=-=-=-=- 以下内容由 phua1991 在 2006年06月09日 04:34pm 时添加 -=-=-=-=-
Mis a word.
I mean
Logic is NOT the whole of debate, but...

phua1991

Let us ignore the term  先決條件. As I said previously the definition is vary and depend on how you use it.  I did not see the whole game of 組織年輕化 是/不是 鄉團持續發展的先決條件, I just saw the very end session. I don’t know how strong both side can support their definition is correct. It may both side, as usual as other teams, also can not provide that.  In addition, let us ignore the result of the game and focus on the logic on those terms. Ok?

If the debate topic related to relation (condition, 条件), the debater needs to set out 1 of the following logic explanation.

There have 3 condition relations as stated below:
1.有A就有B，有B未必有A，是为A是B的充分条件
2.有B就有A，有A未必有B，是为A是B的必要条件
3.有A就有B，有B就有A，是为A是B的充分必要(充要)条件

Equal to
1.有 “組織年輕化”就有 “鄉團持續發展”，有 “鄉團持續發展”未必有 “組織年輕化” (may cause by other factor)，是为 “組織年輕化”是 “鄉團持續發展”的充分条件
2.有 “鄉團持續發展” 就有 “組織年輕化”，有 “組織年輕化”未必有 “鄉團持續發展” (may cause by other factor)，是为 “組織年輕化”是 “鄉團持續發展”的必要条件
3.有 “組織年輕化”就有 “鄉團持續發展”，有 “鄉團持續發展”就有 “組織年輕化”(no other factor)，是为 “組織年輕化”是 “鄉團持續發展”的充分必要(充要)条件

I do not know how affirmative side making their argument (as I do not heard their speech), I think their properly use relation 1 or 2.
If the negative side use relation 3 to definite the condition, than it will increase the difficulty of the affirmative side to prove their argument.
If we required the judge be objectivity, be a white paper. Then, the debater needs to provide the reason why it should be 1 or 2 instead of 3 or another way.
Try to understand these 3 relation, it is important in most debate topic analysis.

Hope the above explanation will help you.

aYaKO

跟以上两位相比，我应该是超级晚生吧？
你们的“打破沙锅问到底”的精神令人佩服得五体投地啊～～
加油～

周自横

前輩說的“充分”、“必要”、“充要”之間的區別，晚生都能弄懂了...多謝前輩了！

所以總的來說，我們可以歸納為---第二因的存在與否，影響因與果之間的關係是“充分”、“必要”或“充要”...對嗎？
那麽，“先決”到底是三者的哪一個？爲什麽？

phua1991

You got the point. Regarding what is the correct (?) definition of 先決條件, I will say I am neutral on this point depend how you want to manipulate this term to side you.
You have not told me yet, which relation the affirmative side uses in this debate?
From the very end session I saw, I think if the affirmative side emphasize their definition, the negative side also very difficult to prove their definition is correct.

日不落帝国

那场比赛他们说的是组织年轻化是持续发展的先决条件，
感觉上循人说的也只是先决条件，
那时他们说的是组织年轻化才有持续发展，
没有的话未必没有持续发展（不能否认有其他因）
不过他们一直说的是必要条件，
我想他们或许弄错了...如果照大家说的他们讲的实际是充分条件...
而必要且充分是反方提出的...

周自横

正方的邏輯是：
要鄉團持續發展，就要組織年輕化；不過組織年輕化之後，不必然會帶來鄉團的持續發展...

反方的反駁是：
你既然說是先決條件，而先決條件是“無之不必然，有之則必然”（反方自己的邏輯），那位和我們看到有鄉團沒有年輕化卻可以持續發展；有鄉團年輕化卻持續發展不起來...

總結：反方漠視正方的定義，沒說爲什麽他們的定義不成立而自己的定義成立。並用自己的邏輯、先決條件的定義來攻擊正方的判斷標準...

phua1991

To 周自横
So it is relation 2 vs. relation 1?

Show you an amazing example,
I get it (and amended it) from Kedah Debater Forum

考取良好的成绩, 往后的日子赚大钱
What is the relation of this statement?
充分条件? No, since some people 考取良好的成绩, and not 往后的日子赚大钱.
必要条件? No, since some people 往后的日子赚大钱, and not 考取良好的成绩
充分必要(充要)条件? No, as stated above.

CONCLUSION: These are NO relation !!!??

You can replace the A and B by other thing, like 儒家思想 and economic development, attend class and good result, 辩论活动 and 耽误了学业, 辩论活动 and improve 逻辑etc.

All no relation (you always able to find some exceptional case)

Is logic useless? what is the trick?

n_n

周自横

晚生覺得：其實，邏輯的判斷要基於學問的基礎。

晚生相信任何事物兩者閒並沒有絕對的關係。所以，單方面的邏輯往往加諸了情況很多前提、假設...和實際情形不符合...
邏輯學只是簡單的判斷學問。就像前輩提過的，用邏輯學論證辯題普遍上也只是在應用枚舉推理和歸納論證；並不是，也不會絕對吻合。
但這就表示邏輯學沒有用嗎？不。正因爲邏輯學有這樣的基礎，所以他讓人跟懂得判斷。如果基本的判斷都不懂，又如何判斷錯綜複雜、環環相扣的社會實際情形呢？
學邏輯是好的。但是讓邏輯、數學、科學泛濫成災，會造成人文價值的匱乏。

晚生淺見，還望賜教。[br][br]-=-=-=-=- 以下内容由 周自横 在 2006年06月11日 05:53pm 时添加 -=-=-=-=-
應該是
正方用“必要”（無之必不然，有之不必然---有A未必有B，無A必無B）的闡釋；
反方用“充要”（有之必然，無之不然---有A必有B，無A必無B）的反駁。

phua1991

The answer is not such simple. We need to aware that the logic has 2 main fields: 1. Formal logic and 2. Informal logic. Informal logic is more suitable for the use of debate. The Toulmin Method which common used by US and Taiwan debater is one kind of informal logic application.

If you really interest you may start build up your basis logic knowledge through formal logic (from most of the ‘logic’ books in the market or the weblink I recommended previously). Then, look out for informal logic (from some of the ‘logic’ books published after year 2000, Chinese books are quit leave behind on this topic, or some of the books regarding critical thinking or reason thinking).

For the difference between these 2 fields, you can refer to ‘informal logic’ entry in Wikipedia or other encyclopedias available on the web. Has a very good

For the debate skill, I still remember long time ago, when a Nobel winner implied to say that Confucian has not relation with economic development in Far East Asia. The 杜维明 has a very good reply to identified the difference approach to view such question.

Hope the above advise will help you since it is very difficult to discuss though black and white (my juniors also are not very understood).

n_n

见光死的猪扒

我想请问一下组织年轻化不是乡团持续发展的先决条件，是什麽意思？？？？

lion

谁能帮我排版啊