20160224

一個哲學小驗證


早兩天在臉書見到一位朋友貼出英國哲學家 G. E. M. Anscombe 的一段文字:

"Think of the English sentence 'If you can eat any fish, you can eat any fish', which sounds like a tautology, but is, on the contrary, a false judgment. Any native English-speaker will understand that sentence: few could explain how it works." (An Introduction to Wittgenstein's Tractatus, pp.140-141)

為方便論述,以下我會用 '(E)' 來代表 'If you can eat any fish, you can eat any fish'。

我看過這段文字後,大感疑惑。首先,我自己的直覺判斷是 (E) 為真;此外,我懷疑是否任何 native English-speaker 都會如 Anscombe 所言,判斷 (E) 為假。在 (E) 裏,'you can eat any fish' 出現了兩次,假如兩次表達的意思都一樣,(E) 便明顯地為真;要判斷 (E) 為假,便須要將這兩個 'you can eat any fish' 理解為不同的意思,問題是,這真的會是 native English-speakers 感到最自然的理解嗎?

Anscombe 是 native English-speaker,也是出色的哲學家,是維根斯坦最有名的學生,這段文字亦權威語氣十足,然而,這些事實都不能稍減我的疑惑。於是,我決定做一個小小的驗證,找我認識的 native English-speakers 作調查對象,看看他們怎樣判斷 (E)。

我先後問了四十人,向他們展示 (E) 之前,我先強調這不是甚麼哲學或邏輯難題,他們只須要根據最直接自然的理解,判斷我展示的句子是否為真。結果是二十六人判斷 (E) 為真,只有十四人判斷 (E) 為假。

Anscombe 認為任何 native English-speaker 都會判斷 (E) 為假,那是錯的,不過,她認為判斷 (E) 為假的人很少能夠 "explain how it works",卻似乎是說對了。那十四個判斷 (E) 為假的人之中,只有一個能夠清楚解釋他為何這樣判斷:他將第一個 'you can eat any fish' 理解為 'any fish is edible'(「任何魚都是可吃的」),將第二個 'you can eat any fish' 理解為 'you are in a position to eat any fish' (「你可以吃到任何魚」)。其他判斷 (E) 為假的人未必這樣理解,而這個理解亦不見得是最自然的。

這個小驗證還有些有趣的資料:那四十人之中有十一人是在大學教哲學的,十一人之中只有一個判斷 (E) 為假;其餘二十九人都是我的學生,其中六人主修哲學,六人之中也是只有一個判斷 (E) 為假;餘下的二十三個學生中,判斷 (E) 為假的卻比判斷 (E) 為真的稍多 --- 十二比十一。讀哲學的大比數不同意 Anscombe 的看法,何解?

在這個小驗證裏,我問的 native English-speakers 都是美國人;Anscombe 是英國人,她說的 "native English-speakers" 會不會只是指英國人?這點我不得而知。假如讀者中有英國朋友眾多者,對這問題有興趣的,不妨也做個類似的小驗證,說不定會有另一些有趣的發現。

10 則留言:

  1. 會不會是類似中文的這個意思:
    "如果你能夠吃任何魚的話,你可以(去)吃任何魚"。

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    1. 補充一下:
      就如類似中文講的:“如果你能夠唱歌,你可以唱歌”;“如果你能夠跳舞,你可以跳舞”;
      If you can sing, you can sing.
      If you can dance, you can dance.
      至於有什麼哲學含義,那就要請教王Sir了。

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    2. 因為 can 有兩個不盡相同的意思:能夠,可以。這兩個意思應該說是相近但也不盡相同。
      有聽過一些西人朋友講:You can do, you can do; you can not do, you can not do". 他們當時給我的感覺是:如果你能做的話你就做,否則也不用勉強,因為那沒有什麼大不了的事。
      就如之前的例子說的如果你能夠唱歌的話你可以唱歌,但如果你不能夠唱歌的話,也無需勉強,因為那並沒有什麼大不了的事。

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  2. I know you can eat my fish, but you cannot.

    說不定現時的 native English-speaker 和當年的,看法也會有不同。用字會隨時代改變。

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  3. 分歧不一定只在 "can", 還有在 "any",

    e.g. "if you can do anything, you can do anything", even if I can do something here, I can't do all kinds of things.

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  4. 我猜她不是向native speaker 展示E,而是讀出E。如讀的時候兩個can發音不一樣,聽者很容易便會聽出讀的一方在imply 兩句的意思不同。

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    1. 她只是在文章裏寫出,應該接近展示多於讀出。

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  5. That's interesting. The statistics is...hmmm... somewhat surprising to me. But with so many people in the sample having a philosophy (or logic?) background, it maybe biased. Wait. Maybe not. See below, especially for the question I'd like to ask Wong.

    Disclaimer: I'm not a native English speaker. And the limited English I know is mostly American English. So, don't sue me if I've got it wrong. Haha.

    Having said that, I will give my 2 cents:
    If one looks at the sentence and reads it as "if A then A," it certainly sounds like a tautology. (Or E is true as a tautology.) But we are not doing logic here and probably some people would not interpret it like that. Even with some math background I would not read it as such when dealing with everyday language, which is very fuzzy at times.
    Now then, how would I interpret it, giving the benefit of doubt to the speaker, that (s)he is probably not saying some empty words?
    I would interpret the first any as one (in random, or even a particular one) and the second as (any of) all (the others) .
    So, I will read it as: If you can eat one (or this, or this yucky, or whatnot) fish you can eat any of all the other fish. Whether this is a false judgment (statement?) or not, or if it is even a statmeent (see the sentence I've made up below, I wouldn't call it a statement in that context), I will leave it to philosophers.

    Oh, a question. Wong, did you ask the people who said E is true how they interpreted the sentence? They may have interpreted it in a way like how I would interpret it or some other ways and still thought E was true, but not as in a tautology.

    An "example" I've just made up: A sergeant told one of his soldiers (who seemed "weak") before they engaged the enemies, "If you can kill any man you can kill any man."

    Some meanings of any from m-w.com:
    1
    : one or some indiscriminately of whatever kind:
    a : one or another taken at random
    b : every —used to indicate one selected without restriction
    2
    : one, some, or all indiscriminately of whatever quantity:
    a : one or more —used to indicate an undetermined number or amount
    b : all —used to indicate a maximum or whole
    c : a or some without reference to quantity or extent
    3
    a : unmeasured or unlimited in amount, number, or extent
    b : appreciably large or extended

    --zpdrmn

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    1. "did you ask the people who said E is true how they interpreted the sentence? "

      - They thought it's tautological.

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