Tag Archives: 哲學

教授與學生 (啟蒙版)

教授與學生這一篇文章在網絡上廣為流傳﹐很多基督教徒也常常引作傳教之用。只是這文章的原裝版本錯誤甚多﹐那位哲學教授的學問更是連小學生也不如﹐讓人聽起來很像基督教比哲學優勝﹐而然文中學生所打倒的不過是稻草人罷。文中教授針對神所題出的質疑﹐其是千多年來一直困擾神學家的苦難題﹐並不是新奇的思想理論。至於說信神不乎合科學﹐嚴格來說也是對的﹐只是同樣的不信神也不乎合科學﹐因為科學根本不能應用在宗教上。最近我在某論壇上看見教授與學生的啟蒙版﹐一語中的的捅破文中的思辯謬誤﹐特此轉載過來和大家分享一下。


「就讓我解釋一下,信耶穌在科學上有甚麼問題。」一個無神論的哲學教授上課時說。他頓了一頓,叫了一個新生站起來,問:「孩子,你是基督徒吧,是不是?」

「是,先生。」

「那麼你是信上帝了?」

「絕對是。」

「上帝是不是善的?」

「當然!上帝是善的。」

「對了。」

「那麼你是善還是惡?」

「聖經說我是惡的。」

教授露齒而笑:「啊,聖經!」他想了一回,說:「給你一個問題。如果這裏有個病了的人,你有能力醫治他,你會醫治他嗎?起碼試一試?」

「我會的,先生。」

「那麼你便是善的了……」

「我可不會這樣說。」

「為甚麼不會呢?當你有能力,你會去幫助生病和殘廢的人……事實上當我們有能力,我們大部份人都會這樣做……但上帝不會。」

沒有回應。

「祂沒有這樣做呀,祂有嗎?我的兄弟是基督徒,他患了癌症,懇求耶穌醫治,可是結果他死了。耶穌怎會是善的?唔? 你能答我嗎?」

沒有回應。

老人表示同情,「不,你不能回答,是嗎?」他拿起書桌上的杯子,喝了一口水,好讓那學生有時間喘一口氣。教哲學時,得對初學者寬容一點。「年輕人,我們再開始過吧。」

「呃……是。」

「撒旦是不是善的?」

「不是。」

「撒旦從那裡來?」

那學生支吾地說:「從……上帝那兒……」

「對了,上帝造了撒旦,是不是?」老人用瘦骨嶙峋的手梳梳稀薄的頭髮,對嘻嘻笑著的學生聽眾說:「各位,我想這個學期將會十分有趣。」他回過頭來,對那個基督徒學生說:「孩子,告訴我,這個世界是否有惡存在?」

「是的,先生。」

「哪裡都充滿了惡,是不是?上帝是不是創造所有東西?」

「誰創造了惡?」

沒有回應。

「世上有疾病,是不是?不道德呢?仇恨呢?醜陋呢?所有使人苦惱的事──存在於這個世界嗎?」

那學生顯得坐立不安,勉強答道:「是的。」

「誰創造它們?」

沒有回答。

教授忽然提高聲調說:「是誰創造它們的?請告訴我!」教授把臉湊到那基督徒學生面前。

一把輕而平穩的聲音說:「孩子,上帝創造了所有的惡,是不是?」

沒有回應。那學生嘗試堅定地直視教授,但失敗了。教授突然走開,在班前踱來踱去,活像一隻老黑豹。全班都被迷住。「告訴我,」他說,「這個上帝不斷地創造 一切的惡,衪怎會是善的?」教授揮舞著雙臂以包括著世上所有的邪惡。「這個善的上帝所造的仇恨、殘酷、痛苦、折磨、死亡和醜陋,以及所有苦難充斥著這個世 界,是嗎,年輕人?」

沒有回應。

「你看不見這一切都在嗎?唔?」

教授走上前,對那學生輕聲說﹕「上帝是善嗎?」

沒有回應。

「孩子,你信耶穌嗎?」

那學生顫抖的聲音出賣了他:「教授,我信。」

老人惋惜地搖搖頭。「科學說你有五官去確認和觀察你周遭的世界。你有看見過耶穌嗎?」

「先生,我沒有。我從來沒看見過他。」

「那告訴我們,你有聽見過耶穌嗎?」

「我沒有,先生。」

「你有否觸摸過你的耶穌、嚐到你的耶穌、或是嗅到你的耶穌……
實際上,你對上帝有沒有任何感官認知(譯按:請注意,教授沒有說這個認知是直接還是間接、透過儀器等等的)?」

沒有回應。

「請回答我。」

「沒有的,先生。我恐怕沒有。」

「你恐怕……你沒有?」

「沒有,先生。」

「你還信祂?」

「……是……」

「那真需要信心呀!」教授向學生微笑:「根據實證、可測試和可證實的定律,科學說你的上帝不存在。孩子,你以為怎樣?你的上帝在哪裡?」

那學生答不上來。

「請坐下。」

那位基督徒坐下來……被擊敗了。

另一個基督徒舉手說:「教授,我可以發言嗎?」

教授微笑著說:「啊,另一個基督徒先鋒!來,來,年輕人,給大家說些恰當的見識。」

那基督徒環視房中四周,「先生,你正在提出一些有趣的論點。現在我有一個問題想問你。有一樣東西叫熱嗎?」

「有,」教授答,「世上有熱。」

「有一樣東西叫冷嗎?」

「有的,孩子,世上亦有冷。」

「沒有的,先生,世上沒有冷。」

教授的笑容凝結起來。班房突然變得很冷。第二個基督徒繼續說:「你有很多種熱,很熱、超熱、巨熱、白熱、少少熱或是沒有熱,但我們沒有一樣東西叫 『冷」』。我們有零下458度(譯按:華氏),這是沒有熱,但就不可以再降低些。沒有一樣東西是叫冷的,不然我們會有冷過零下458度的溫度──先生,你 看,冷只是一個用來形容欠缺熱的字。我們不能量度冷。因為熱是能量,熱可用熱量單位來量度。冷不是熱的相反,先生,這只是熱的欠缺。」

……一片死寂。

教授回應:「首先,我沒有說過冷是熱的相反。你暗示我有,硬說成是我說的。冷是熱的相對量度方式,特別是低過零度時。所有零下的溫度都可以用冷的 定義來形容。如我所說,冷不是熱的相反,僅是一個對熱、涉及它在絕對零度的相對狀態的描述。再者,我能引申你論點的前提,及將之應用在對體積的描述。沒有 一樣東西叫收縮,因為小只是大的欠缺,或者體積增長的欠缺。宇宙中最小的粒子是在原子邊緣的電子。所有收縮的東西都只能收縮到這個體積,不能再小,我們可 以說收縮不存在嗎?」

那基督徒困惑、迷亂起來。這個基督徒已準備放棄,不然他就會說出不知所謂的東西,在餘下的學期成為別人的笑柄。

寂靜掠過班房。一陣短暫的停頓後,聽眾開始騷動起來,靠在椅邊跟鄰座交換意見。

一張紙從那個基督徒的手中落下來。紙上是一份他預先準備好的問題清單;那些問題現在提出來就太荒謬了。由於那個基督徒差不多準備返回座位,他被要求留下來挑戰教授。他只好不情願地照做。

「教授,這個世上有沒有一樣東西叫黑暗?我知這現在是一條愚蠢問題。」

「孩子,這現在的確是一條愚蠢問題。如果沒有黑暗的狀態,夜晚是甚麼?你在指責甚麼……?上帝不是在你的聖經說『讓這裡有黑暗』’嗎?你在否認這個所謂上帝的舉動嗎?」

「那麼你是說有一樣東西叫黑暗了?」

「我會答『是』──假如用你的說法、根據你的聖經;我會答『否』──因為黑暗是一個狀態而不是一件東西。」

「你又錯了,先生。黑暗不是某種東西,而是欠缺某種東西。你能夠有低光、正常光、強光、閃光,但如果你連續地沒有光,你是甚麼都沒有,而這叫黑暗,是不是?」

教授稱:「笨蛋,這正是我所說的。我說黑暗不是一種東西,就像飢餓、細小、富有、貧窮、黑暗、光明都不是一種東西。黑暗可以是某東西相對存在的狀態。」

「這是我們用來為字詞定義的意思。在真實情況下,黑暗不是一樣東西。如果它存在,你就可以造些較暗的黑暗及給我一瓶黑暗。教授,你可否……給我一瓶較暗的黑暗?」

「當然,只有像你的笨蛋才會問一條問題誤導別人去表示黑暗是一樣東西。你可否給我一瓶『細小』、『飢餓』。你的上帝自稱全能又可否如此?」

儘管佔了上風,教授還是對他眼前厚顏的年青人微笑。「這將會是一個很好的學期。年輕人,你介意告訴我們多些你的想法嗎?」

「好的,教授。我的意思是,你的哲學前提一開始就錯了,所以你的結論必定有錯……」

教授生氣起來:「錯了……?你好大膽……」

「先生,我可以解釋一下我的意思嗎」

全班都豎起耳朵。

「解釋……噢,解釋吧……」教授幫那基督徒從剛才給教授智慧的表現鎮懾的不穩狀態恢復過來。

一如平常,他是如此和藹可親的。他揮動雙手安靜全班,讓那學生繼續說。

「你正在二元論方法的前提上下工夫,」那基督徒解釋道,「例如有生存有死亡,有好神有壞神。你將上帝的概念看成有限的、我們可量度的東西。先生, 科學連思想都解釋不了。它用到電力和磁力,但這些都不曾被看見,對它們離完全了解還差得遠。將死亡視作生存的相反,是忽視死亡不是一種實在的東西的事實。 死亡不是生存的相反,僅是生存的欠缺。」

「我有說過生存是死亡的相反嗎?我有說過用二元論方法來看待事物嗎?沒有一個狀態是相反的。就像嬰兒不是老人的相反、或健康的新生女嬰不是患癌的 老婆婆的相反。所有東西的狀態只存在於一條連續統一體的線上。人類是四腳動物和植物的延續。這是進化,著眼於生長的科學。你從未見過人家寫聖經,我們可不 可說聖經是外太空生物寫成的?」

那年輕人從書桌拿起一份鄰座在看的報紙。 「教授,這是這個國家其中一家最下流的小報。是不是有樣東西叫不道德?」

「當然不是,經驗和事實的好壞只在於我們為它賦與的意義。沒有東西是不道德的,就如沒有東西是道德的。」

「先生,你又錯了。你看,不道德僅是道德的欠缺。有沒有一樣東西叫不公義?沒有。不公義是公義的欠缺。有沒有一樣東西叫惡?」那基督徒頓了一頓。「惡是否善的欠缺?」

「不是,不道德不是道德的欠缺。不道德是持有此看法的人眼中的道德。就是如此。」

那基督徒繼續說:「教授,如果世上有惡,而我們都認同,那麼上帝──如果存在──必定是透過一個有惡的機制在工作。那是甚麼工作呢?聖經告訴我們,這工作是看看我們每個人自由意志的意願,是選擇善還是惡。」

「邪惡與正義是一個零和遊戲,原則上互相抵銷對方。一個人的舉動可以被同時考慮成邪惡和正義。它們同時存在,並非互相排斥。為甚麼你覺得即使上帝 存在,祂也是在工作的?這只是你的假設,認為上帝不會袖手旁觀。如果邪惡是那個機制,那它的目的是去減弱那所謂正義,因為這同樣是一個零和遊戲。」

教授面露慍色:「作為一個哲學科學家,我不會將這個情況視為可在任何選擇上做任何事;作為一個實在論者,我絕對不承認上帝這概念或其他神學因素等可作為對世事解釋之一部份,因為上帝是不可被觀察的。」

那基督徒回應:「我覺得在世上,上帝道德準則的欠缺(譯按:學生的意思是指不道德)大概是最能被觀察的現象。」

「甚麼東西令你覺得,只因道德準則不是出自聖經這個世界就沒有道德準則?」

「每週對它的報道為報紙賺來以億計的金錢啊!」

「那麼報紙對基督徒暴力舉動的報道呢?我們經常讀到類似的新聞。那些人給上帝的意願控制了思想。」

「教授,告訴我,你會告訴學生他們是從猴子進化出來嗎?」

「如果你是說自然進化過程,年輕人,我當然會。」

「先生,你有親眼觀察過進化嗎?」

教授冷冷地瞪著他的學生。

「教授,由於連觀察過進化的人都沒有,連證明這個過程是在進行都不能,先生,你這豈不是在教授你的意見而已?抑或說你此刻不是科學家,而是傳教士?」

教授不滿地說:「你能證明你的胃已經吸收了你今天的早餐嗎?五十年前的早餐又怎樣?你能用肉眼證明地球是圓的而不需任何科學儀器?如果你目睹有人 槍擊一個受害者,由於子彈進入受害人的身體後就永遠不能被你看見,你能證明那受害人真的被子彈所殺嗎?如果你在法庭作證,指你目睹甲向乙開槍,你不只在提 供意見。再者,子彈被槍管射出飛過空中,快得你永遠看不見。如果我們連自己的觀察都不能相信,你和你的上帝的精神連繫還有啥值得相信。在哲學討論中,我就 即管不理你的無禮行為。現在你說完沒有?」

「那麼你不接受上帝的道德準則去衡量甚麼是正義?」

「如果任何人相信任何一套道德準則,他只會很易受影響去相信任何其他的道德準則──我選擇科學!」

「啊,科學!」那學生露出鄙夷的笑容。「先生,你正確地指出科學是觀察現象的學問。科學的前提同樣有錯……」

教授急促地說:「科學沒有錯,只是你現在對科學的理解有錯。科學在人類在世上漫步前早已存在。所有的答案已在,它們只是在等待被發現。」

教授的洞察令全班騷動起來。那基督徒一直站著,直至騷動平息下來。

「為了引申你先前向另一位同學提出的論點,我可否給你一個例子來解釋我的意思?」

教授明智地保持沉默。

那基督徒環視房中四周。「班上有沒有人看見過教授的腦袋?」

全班爆發出巨大的笑聲。

那基督徒指向他年老、漸漸垮掉的導師。

「這裡有沒有人聽見過教授的腦袋……觸摸過教授的腦袋、嚐過或嗅過教授的腦袋?」

看來沒有人試過。那基督徒惋惜地搖搖頭。「看來沒有人對教授的腦袋有任何感官認知。那麼, 根據實證、可測試和可證實的定律,科學說教授沒有腦袋。」

學生的古怪言論引起了教授的興趣。教授於是問他有沒有閱讀過任何關於科學的東西。

「沒有啊,」學生說。「我所知道的都從教會聽回來。」

「孩子,那正好解釋你對科學的無知。」教授說。「對一種東西的經驗知識不一定來自直接觀察。我們可以觀察那東西引起的效果而知道它一定存在。電子從來未被觀察,但它們能產生一道能被觀察的痕跡,所以我們知道它們存在。」

「哦,」基督徒說。

「沒有人觀察過我的心臟,但我們能聽到它跳動。我們也可從別人的經驗知識得知,沒有人可以沒有心臟(真的還是人造的)而生存,最少在沒有連接到一些醫療設備的情況下。所以我們知道我有心臟,就算我們未見過它。」

「哦。這很合理,」基督徒學生說。

「同樣地,我們可以知道我有個腦袋。如果我沒有的話,我就不能說話、走路等等了,不是嗎?」教授說。

「大概不能了。」

「事實上,如果我沒有腦袋的話,我就不能做任何事了。或許,除了成為一位電視傳道家吧。」全場大笑,就連那位基督徒也笑了。

「進化論已被知道是真的,是因為証據。」教授繼續說。「它是對化石紀錄最好的解釋。就連有名的創造論家也承認,由爬蟲類到哺乳類動物的演變,在化 石紀錄中有良好的證據。一個創造論家的辯論小組,包括Michael Behe和Philip Johnson等,在一埸電視轉播的辯論中正承認這點。那是在Buckley的”Firing Line”節目中。你有收看嗎?」

那位基督徒學生清清嗓子,然後低聲說:「我的母親不準許我收看教育電視節目。她認為那會削弱我的信心。」

教授搖頭嘆息。「知識確是削弱信仰的途徑呢,」他說。「但無論如何,進化論是對已被觀察的現象的最好解釋。」

基督徒急忙問:「你-你指我們見過它?」

「當然了。進他就在最近發生過,而且還繼續發生。並非在夏威夷土生土長的鳥和昆蟲在數世紀前被送到該地。他們都已進化成能夠適應當地的植物。所以,進化在有紀錄的歷史,而且是近代的歷史中發生過。你知道嗎?」

「病毒和疾病也進化成有抗藥性。這不僅能被觀察,更是科學家每日需要對抗的主要問題之一。倫敦地下鐵路隧道裏的蚊字因為與其他蚊子群隔絕而進化成另一個種類。但是,進化論談夠了。那和我們的論題-惡-沒有關係,對嗎?」

「嗯……」

「它和我們的論題有什麼關係呢?」

「如果你不信上帝的話,你一定是相信我們從猿猴而來。」

教授笑著說:「進化論者並不相信人是由猿或猴而來。他們相信的是人和猿有共同祖先。」

「哇!」基督徒說。「教會不是這樣告訴的。」

「我能肯定。他們不能反駁進化論,所以才散佈關於進化論的謊言。但你不知道很多基督徒也相信上帝透過進化來創造人嗎?」

「我不知道。」

「事實上,在我剛才提到的辯論會中,四位講員中的兩位都是有神論者。其中一位更是教士呢。」

「真的嗎?」

「真的。很多基督教教派都接受進化論。天主教作為基督教最大的教派,也和進化論相容。所以進化論在這裏不相干,對嗎?」

「沒錯。」

「就算只有無神論才能相信進化論,而這不是真的,甚至就算沒有証據支持進化論,而這也不是真的,這也不能解釋惡,對嗎?那是沒有關係的。」

「我明白了,」基督徒說。「我也不知道為什麼我會提出這論點。我想我以為那是沒有証據而相信的例子。」

「嗯,」教授說。「如你所見,並不是如此。進化論有很多支持的証據,就算它真的沒有証據,這也和惡的論題無關。當我們繼續哲學課時,你就會明白如何運用你的理解能力去把重要的和無關的問題分開。」

「我想我已在學習呢,」學生凝視著地上說。

「讓我們回到惡的問題,」教授說。「你說惡是善的欠缺。那如何解決惡的問題呢?」

學生沒趣地答:「如果惡是善的欠缺,那麼上帝就沒有創造惡。」很明顯,這是他死記硬背,經常重覆的答案。

教授聳聳肩膀說:「好了,現在就假設這是真的。但這仍然沒有解釋惡。如果一次海嘯把一個城鎮夷為平地,奪去十萬人的性命,那是惡嗎?」

「那是善的欠缺,」學生說。

「那就如何?問題是為什麼上帝不阻止這場災難。如果上帝是全能的,衪可以阻止它。如果上帝是全知的,衪也會知道它何時發生。所以他是否創造了那次海嘯並不重要。我們要知道的是衪為什麼不做任何事去阻止它。」

學生顯得很困惑:「但衪為什麼要阻止它?這不是衪的錯呢。」

「如果一個人有能力去阻止海嘯把城鎮夷為平地,並這個人故意沒有去阻止它,我們不會說這個人是善的。就算那人說,『那不是我的錯,』我們也會因為 一個人在上千人要死去時見死不救而吃驚。所以,如果上帝能阻止天災而沒有做的話,我們按此推理就不應說上帝是善的。事實上,我們大概會說上帝是惡的。」

基督徒學生想了一會,說:「我想我需要認同。」

「所以把惡重新定義為善的欠缺,完全沒有解決惡的問題,」教授說。「極其量,那只顯示了上帝沒有創造它,但沒有解釋為什麼上帝沒有阻止它。」

基督徒學生向教授擺動著手指說:「但這是根據我們人的標準。如果上帝有更高的道德觀呢?我們不能用我們的標準判斷他。」

教授笑了。「那麼你的論辯就失敗了。如果你承認上帝不符答我們對善的標準,我們就不應稱他為善。論辯完畢。」

「我不明白啊,」學生皺著眉說。

「如果我在外面看到一輛有四個輪胎,一個金屬車身,一個駕駛盤,一個馬達等的車輛,而它符合汽車的定義的話,它是一輛汽車嗎?」

「當然是了。」基督徒學生說。「汽車就是這樣的。」

「但如果有人說,按照另一些定義,它能算是一輛飛機。那是否意味著它不是一輛汽車?」

「不,」學生說。「它仍然符合汽車的定義。那就是我們說它是汽車的意思。它不符合飛機的定義,所以我們不應那樣稱呼它。」

「正確。」教授說。「如果它符合那定義,它就是那東西。如果神上帝符合善的定義,衪就是善的。如果衪不符合的話,它就不是。如果你承認衪不符合我 們對善的定義,衪就不是善的。說衪或許根據另一些定義是善的,毫無用處。如果我們想知道根據我們的定義,衪是否善的話,你已答了那問題。上帝不是善的。」

「我不能相信!」基督徒學生說。「換成數分鐘前,我或許已經在取笑神不是善的說法。現在我卻同意。上帝不符合善的定義,所以衪不是善的。」

「慢著,」學生說。「就算我們不稱衪為善,根據另一些標準,上帝仍可以是善的。任憑我們如何想,上帝仍然可以根據衪自己的道德觀說衪是善的。就算我們不能稱衪為善,那不代表他在另一些標準中也不是善的。無論如何,衪可以有自己的一套定義呢。」

「唉呀,你不會想推進上帝可能在另一些標準中為善的看法的。」教授說。

「有何不可?」

「如果衪對事物的定義和我們的截然不同,衪也可能對其他的事物有著和我們不同的看法。衪可能對永賞、永生等都有自己的一套看法。你在天堂的永生可能只有一年,也可能是一千年的折磨。上帝可以說,衪有自己一套包括痛苦折磨的定義。」

「對啊!」基督說跳起來睜著眼說。「如果上帝可以重新定義任何詞語的話,任何事情也可以發生。上帝可以把所有信徒都送進我們稱為地獄的地方,然後說那裏是天堂。衪可以給我們在天堂十天,然後說那是衪對永恆的定義!」

「現在你總算在思考了!」教授指著學生說。「這正是哲學課要為學生帶來的。」

基督徒學生繼續說:「上帝也可以答應給我們永生然後不給我們,說那是衪對遵守承諾的定義!」

「是的,是的,」教授說。

「我真不敢相信我曾經迷上基督教這東西。它是那麼的不堪一擊,」學生搖頭說。「只要想一陣子,教會在主日學中教我的所有論據全都崩潰了。」

「看來就是了。」教授說。

「我今晚就要去我的教會,把我的想法告訴牧師。他們從沒有把如此重要的事告訴我。而且他們肯定沒有告訴我關於進化論的真相呢!」

那位學生,站起來的時候還是一位基督徒,現在坐下來時已變成一位無宗教信仰者。他還開始運用他的腦袋-因為這正是腦袋的作用。其他學生看到他坐在那裏,都目瞪口呆好一陣子。他們知道,他們都見證了一個人生命的轉變,就是一位年青人的心智從謊言和教條轉向對真相樸實的追求。

學生你看看我,我看看你,然後開始鼓掌。這再變成了歡呼喝彩。教授也大笑著,滿意地向學生鞠躬。當學生都安靜下來後,教授繼續講課。從此,哲學課上每天坐無虛席,直到學期的結束。

哲學功課: Problem of Induction

David Hume has introduced one of the problems in epistemology that baffled many philosophers for ages. In his argument about the problem of induction, he made the claim that inductive inference cannot be rationally justify. Many philosophers had proposed solutions to this problem, such as Hume’s own psychological solution and Kant’s synthetic a priori knowledge solution. However none of them can solve the problem of induction with a satisfaction. This problem is finally resolved by 20th century philosopher Karl Popper by introducing a paradigm shift in the definition of knowledge. This article will first outline Hume’s claim about the problem of induction and the implication of this problem, then it will present Popper’s solution to this problem.

The problem of induction arrived from Hume’s position as an empirical philosopher. Hume believes the source of human knowledge is experience from outside world instead of from reason within our mind. He uses Hume’s fork to divide all human knowledge into two groups, either “relations of ideas” or “matter of facts”. The “relations of ideas” is a prior proposition that can be verified with reason alone. For example, “a circle has no angle” and “pork is pig meat”. The “matter of facts” is a posterior proposition that can only be verified by experience and observations. For example, “the sun always rises from the east” and “it has 400cm of snow in Whistler”. The cause and effect of “matter of facts” are the only concerning matter in human knowledge. Every piece of information in the “matter of facts” has a cause. We know it is going to rain from the dark clouds in the sky. We know that we can take sky train and bus from downtown Vancouver to SFU from the transmit map. Therefore human does not have intelligent without understand the causality between difference pieces of knowledge.

Hume points out the causal connection between two events are discovered by experience but not by reason. Thought induction, we can establish the connection between two events. Induction is generalization work by inferring a claim about an entire population of objects from data about a sample of those objects. We have observed many people die from eating cyanide, so that we can conclude cyanide kills people. However Hume claims that we didn’t actually observe the casual connection between the two events. We only observe a sequence of two events happens one after another all the time and come to the conclusion that there is a causal relationship between them. If we in fact we cannot assert the one event will always leads to another, how can claim we have know anything at all. For example, for many years all birds observed by men have wings. We took it for granted that birds must have wings, until we discover the wingless kiwi bird in New Zealand. Therefore no matter how many winged birds we have observed, we cannot guarantee all birds have wings. The same principle can apply to any other knowledge we have. How can we prove that we will have a full moon next month? We merely expect future events will follow the past experience. We are just assuming the external world is uniform and consistence over time so that all natural phenomena are expected to repeat themselves. This is circular reasoning that we beg the question by assuming the answer we are looking for. Since all our knowledge is based on this assumption that we cannot rationally justify, Hume has shown that we in fact don’t know anything.

Karl Popper is probably the most notable philosopher in the 20th century. His philosophy works changed how the field of epistemology perceives knowledge. For the past two hundred years, the laws of physics discovered by Newton have shaped how philosophers viewed science and knowledge. Science facts are the most reliable form of knowledge in human society. Once a scientific fact is discovered and verified by rigorous experiments, it is thought that the science theory or law will not change. Many great philosophers in the modern age believe that the scope of human knowledge will expand over the time as we discover more scientific facts and add to the existing pool of knowledge. However at the turn of the 20th century, the discovery of a genius scientist Albert Einstein has shaken the foundation of the Newtonian world of physics. His famously relativity theory is compatibility with Newton’s theory. Einstein’s theory is confirmed by the eclipse observations to show that light from distant stars can be bended by the sun’s gravitational field. The consequence of this discovery to philosophy makes us reconsider our understanding of knowledge. We can no longer guarantee the certainty of what we know as any piece of knowledge can call in to question and later shown that it is wrong after all.

Popper’s philosophy shines new lights on the view of science by replacing the traditional static view of science with a more dynamic approach. First he begins with identifying the difference between science and pseudo-science, and defines the properties of a proper scientific theory. Human develop theories to explain the cause and effect between difference events from our experience and attempted to predict the expected result of similar events. Popper thinks that what makes a theory science is not whether the theory is verified to be true nor it is good. A scientific theory has to be falsifiable, namely stated the hypothetical condition that this theory is no longer valid. For example, creationism is not a scientific theory because there is no observation or test could falsify the claim that God created the world in literally 7 days, provided that God can fake any evidences showing the Earth is several million years old . On the other hand, the theory of evolution is science because we can prove it wrong if one day God or some aliens shows up and tell us they had indeed created the Earth. However, Popper didn’t go as extreme as Hume claiming all metaphysics or pseudo science theories meaningless.

Popper has changed the concept of knowledge in philosophy by realizing that there is no certainty in science. Instead he said “science is perhaps the only human activity in which errors are systemically criticized and in time corrected”. Science not only adds new knowledge to the domain, it also replaces existing theories with better ones. It is impossible to prove a scientific theory is ultimately true, we can only claimed that the theory has a tentative status quo, until new there are challenges. When new challenges arise, the old theory either have to be revised to cope with the new findings or limited its scope of assertion to remain useful. The progress of science comes from trial and errors, the continuous regression of hypothesis and observation. Every theory in science not secure, they are open for revision or rejection. All scientific knowledge could probably be false, yet it aspires eventually to the truth. Newton’s theory classical physics is still valid over in the everyday life. Its prediction breaks down when comes to the world of very large scale where Einstein’s relativity theory supplement and correct Newton’s theory. Then along come the quantum theory that is incompatible with both Newton’s and Einstein’s theory on very small scale. The three contradicting theories cannot all be right at the same time. In fact, it is very likely that all of them are wrong. However each theory is served as a stepping stone for a more accurate theory to describe our external world. Although Hume showed that it is not possible to infer a theory from induction of observations, but this does not affect the possibility or falsifying a theory from new observations. Therefore, Popper has solved by problem of induction by changing our concept of knowledge to a more practical and realistic view. Instead of knowing more about knowledge with absolute certainty, we are getting closer to the true nature of knowledge by reducing the degree of uncertainty.

哲學功課: On Fatalism

In this essay I will discuss the conflict between God’s foreknowledge and our freedom. I will first examine the problem of fatalism proposed by Richard Taylor. Then I will reproduce the resolution proposed by St. Augustine and William Rowe.

In chapter six of Taylor’s book Metaphysics, he has concluded determinism will logically lead to fatalism. Fatalism is a belief that whatever happens in the future is unavoidable. Normal people agree on the fact that the past cannot be changed. The fatalists take their belief one step further. They think that the future also cannot be changed. All events, from the past to the future, in the time line are static. We are just players acting out a predefined script; although we don’t necessary know what is going to happen.

One form of fatalism arises from religious beliefs. In this form of fatalism, there exists an omniscient God. This all-knowing, all-powerful God has foreknowledge about all events in the future. Therefore, although the future has not yet arrived, everything is already fixed in the eyes of God. Men may have illusion that their action can change the future, but nothing happen in the world is avoidable. In another words, it is impossible for us to have done it otherwise, according to the foreknowledge of God. There is another form of fatalism does not require the presence of God. The second form of fatalism is based on the law of excluded middle. Every statement about any event in any given time is either true or false, there is no middle ground. Therefore, there exists a set of true statements that describe every event that had happened, is happening or will happen in the world. Again, in another words, this also implies it is impossible for us to do it otherwise, according to that set of true statements.

In the dialog between Augustine and Erodins, Erodins questioned Augustine that the two propositions God has foreknowledge and we sin by free will are not compatible. Since men are inevitable to sin, men should be not judged nor punished. This question is essentially the same as the claim of fatalism, except that Erodins also brought the question of responsibility into the picture. Augustine responded by stating the distinction between will and necessity. He said that by definition the freedom of choices is not a will unless it is in our power. Therefore, the foreknowledge of God does not disprove our power to will anything voluntarily, as long as God also has knowledge of our power over it. Then Augustine further developed his argument claiming that due to we have free will, God’s foreknowledge that we will sin does not compel us to sin. Our sin is caused by our free will, so it is justified to punish those who had sinned. To summarize, Augustine provided an argument that free will is compatible with fatalism, as well as God’s foreknowledge.

In Rowe’s article on predestination, divine foreknowledge and human freedom, he tackled the problem from a different approach. First the he refuted Augustine’s definition of free will and the resolution by separating foreseeing the events from foreordaining the events. Rowe said power of will alone is not sufficient to justify human freedom; the other necessary condition is the power to do otherwise. He used growing old as an example. Say someone wants to grow old, although he indeed is growing old, but he still doesn’t grow old freely. Rowe clarity the problem by outlining the premise and the arguments that leads to the conclusion human has no freedom. The first premise is that God has foreknowledge. The second premise is that since God knows everything we will do, we cannot do otherwise. The third premise is that if we cannot do otherwise, then we don’t really have freedom. In order to dispute the conclusion, we have to reject at least one of the premises.

The first solution is to reject premise three, Augustine’s resolution, which already refuted by Rowe. The second solution is to reject premise two, deny God’s foreknowledge limits us to choose otherwise. Rowe cited the solution suggested by William of Ockham to classify statements about the past into two types: simply about the past and not simply about the past. Statements simply about the past are out of our power to control, however we may alter statements not simply about the past. God’s foreknowledge is statements not simply about the past, therefore God knows everything does not mutually exclude sometimes we have the power to do otherwise. The third solution is to reject premise three, deny God has foreknowledge. This resolution is adopted by many theologians such as Boethius and Thomas Aquinas. In short, this resolution claims God exists outside of time, therefore his foreknowledge does not affect men’s temporal passage. They claim that all events in all time are observed by God at the same moment. Therefore, there is no restriction from God’s foreknowledge limiting men’s freedom to choose otherwise.

To summarize this essay, Augustine made an unsuccessful attempt to solve the problem of fatalism. He made his argument from redefining the meaning of free will is shown too weak. This object is already addressed by Taylor in the end of chapter 5 of his book, Metaphysics. The second and third solution suggested by Rowe has built a much stronger case. Rowe had shown divine foreknowledge is compatible with human freedom by stating free will doesn’t involve altering the past. Taylor has no response to meet these two objects in his book and Rowe had successfully solved the problem of fatalism.

Lastly, the thesis of fatalism is built base on the premise that determinism is true. However from our latest philosophical understanding, determinism cannot be true due to the effect of randomness in reality. If there is no hard coded universal causal relationship between the past and the future, then the claim of fatalism that the future is unavoidable is vague. Therefore, there is no need to solve the problem of fatalism as the conflict between fatalism and free will is not valid in the first place.

哲學功課: Problems of McTaggart and the unreality of time

In this essay I will criticize the unreality of time proposed by McTaggart. First I will outline the arguments on the unreality of time by McTaggart. Then I will reject his premises and deductions one by one to show McTaggart has failed to conclude that time is unreal.

First we have to understand the A-series, B-series and C-series description of time proposed by McTaggart. Let’s start with C-series, which is not a temporal series. The C-series specify the order of events and the time between the events. The B-series adds the notation of direction of time to the C-series. In a B-series, each event is expressed in term of earlier than or later than other events. The A-series adds the notation of the present moment of time to the B-series. In an A-series, each event is either in past, at present or in the future. McTaggart stated that we can only observe time through the forming of either A-series or B-series.

McTaggart then said B-series is not sufficient to describe time. Events in a B-series indicate permanent relations. The earlier and later relationship of events in the B-series cannot describe changes, which is essential for time to exist. Therefore, we are only left with A-series to describe time. McTaggart then claimed that if the A-series is unreal, then time must be unreal. He answered two objections to the removal of A-series will destroy time. The first one deals with imaginary time-series, such as a time-line inside a novel. He dismissed it by claiming time only belongs to existent. The second objection deals with multiple time-series. He dismissed it by claiming the different time-series with multiple moment of present should be rejected because it is incompatible with the A-series.

Next, McTaggart went on to show A-series cannot exist by arguing the A-series is contradictory. He argued that the past, present and future of an event are incompatible determinations. Each event can be in all three incompatible states depending on the verb-from of the event. However using verb-form to explain the states of event induce a vicious circle of infinite A-series. Since A-series has no valid explanation, it is a contradiction and therefore time is unreal. McTaggart’s argument can be summarized in the following table.

  1. Time can only be observed by forming B-series and A-series
  2. Time involves changes, so B-series is out
  3. If A-series is unreal, then time is unreal
  4. A-series is invalid, so it is unreal
  5. Therefore, time is unreal.

Traditionally, there are two camps of philosophers trying to rejecting McTaggart’s claim by two different approaches. The B theorists think that B-series alone is sufficient to describe time. The A theorists accept McTaggart’s claim that A-series is necessary for the existence of time, but reject his claim that A-series is contradictory. Both A theorists and B theorists has their problem dealing with McTaggart, mostly due to they are trapped by framework defined by McTaggart when discussing time. In this essay, I will use a different approach. I will first examine and reject each line of McTaggart’s argument, from step 4 down to step 1 in the table above. In the process, I will uncover some fundamental errors in the McTaggart’s construction of the A-series and B-the series, and provide a new framework of time based on the scientific theories of time.

In step 4 of McTaggart’s argument, he claims that the A-series is unreal because it involves an endless regression of A-series. I am going to reject his claim in three different ways. 1.) An infinite series can also be a real series. All we have to do to take the integration. In mathematics, there are real numbers with endless regression, such as π, e, and irrational numbers. We can only claim that the A-series is not precise in describing the states of an event, but we cannot deduce A-series is unreal from the fact that it merely has infinite circles. 2.) McTaggart tried to solve the problem of time using verb-form is limited by semantic constructs of his language, English. There exist languages with verb-from common to all past, present and future, such as Chinese. The timing relationship of an event in such language is specified explicitly by a time qualifier, such as today, tomorrow, 3 hours ago, last year, etc. 3.) In Dummett’s article, he suggested that using token-reflexive expression, such as now, may refute McTaggart’s argument. He then subsequently claimed the token-reflexive expression of the observer introduce another time-series, hence the endless regression problem still exists. I would answer this by stating that the now event does not require a mind to be an observer. A computer can objectively apply the token-reflex expression to resolve A-series without any existence of mind, thus the now event is real instead of being subjective. Therefore with the help of a real now event, the infinite regression of A-series can be collapsed into a single real A-series with the now event at present.

In step 3 of McTaggart’s argument, he dismissed the objection from the theory of a plurality of time saying it is merely a hypothesis. McTaggart assume time is absolute for all observers. However his viewpoint contradicts with Einstein’s relativity theory, which is a scientific fact. According to principle of relativity, time experienced by an observer is a function of the speed of the observer and the speed of light, which is a constant real value. The faster the speed of the observer, the slower the time he will experience. The relativity of time is confirmed by the 1962 dual atomic clock experiment. In the experiment, two pairs of very accurate atomic clock are mounted on the bottom and the top of a tall tower and it is observed one clock is running slower than another. There is also the famous twins paradox. One of the twins travels in a spaceship near the speed of light. When he returns, he will be much younger than the other twin staying on earth. Each individual has his own frame of reference in time that depends on his velocity and his location related to massive bodies. McTaggart concluded time is unreal because he mistakenly assumed time must be absolute. If time is relative, then there exist many A-series and many instances of present in the universe. Therefore rejecting the A-series alone is not sufficient to prove the unreality of time. Moreover, since the speed of light is real and the speed of the observer is also real, time as a function of those two must also be real.

In step 2 of McTaggart’s argument, he claimed that the B-series indicate permanent relations. Therefore the B-series cannot describe the nature of change in time. McTaggart has made an assumption about the deterministic worldview of time. The B-series is only capable of describing past events. The very last event in the B-series is the now event marking all the possibilities are lying ahead in the future. Take McTaggart’s own example, the death of Queen Anne. Before the event actually happen, there are all sorts of possibilities that Queen Anne could escape death. She could be adducted by aliens preserved as a frozen specimen or she could ascend into heaven like Jesus. If N is earlier than O and later than M, it will only be so if all three events have already happened. If O is in the future, then there is no guarantee this event will exist in the B-series. Therefore, a growing B-series is sufficient to describe time, at least time earlier than the present moment. The becoming of an event is described by its position relative to the now event in the B-series. In this sense, a B-series is equivalent to an A-series after we apply some transform function between the two series using now as the operator.

At last, in step 1 of McTaggart’s argument, he claimed that we never observe time except forming both A-series and B-series and he also claimed that time can be subjective which cannot exists independent of human mind. Let’s try to imagine the following scenario. There is a third world war and every man on earth is killed by nuclear weapons. The earth is heavily polluted and will be inhabitable for the next several thousand years. However, there is a great scientist come up a plan to save humanity. He builds a modern version of Noah’s art safe keeping DNA of every species on earth, including human. The art is controlled by a super computer, which monitors the atmosphere. When the earth becomes habitable, it will populate man and animals from the art’s DNA database through cloning. It is obvious that computer would also keeps track of the time between the last man is dead and the first cloned man is born. During this period, there exists no human mind to subjective perceive time and yet time exists. This thought experiment demonstrated time exists independent of human mind. Moreover, we can also describe time through forming paths in light cones instead of forming the A-series and B-series. The future light-cone is the path of a light pulse from an event and the past light cone is the path of all the lights pulse that will pass through an event. For an event A to be affected by another event B, event A has to lie within the future light cone of event B, since nothing can travel faster than light. Therefore time can be described by the path of lights passing thought the light cones of events. If we use the framework of quantum physics, events change is just a secondary property of time. An event happens on the moment all the probability of the quantum wave equations collapsed into certainty. Then the becoming of an event can derives the change of an event. Therefore, change is not essential to time, instead becoming is essential to time.

In conclusion, in this essay I have rejected every single statement in McTaggart’s argument on the unreality of time. Therefore we have no reason to believe time is unreal based on his arguments. On the other hand, there are plenty of evidence in modern science showing time is real. Hence as a rational being, we should accept the reality of time instead of the unreality of time. In the matter of facts, the questions about the nature of time should no longer be a metaphysical question. It should follow the example of gravity, which moved from the department of philosophy to the department of physics.

References:
[1] J.M.E. McTaggart, “The Unreality of Time”
[2] Michael Dummett, “A Defense of McTaggart’s Proof of the Unreality of Time”
[3] Stephen Hawking, “A Brief History of Time”
[4] Stephen Hawking, “The Universe in a Nutshell”
[5] Wikipedia, “The Unreality of Time”, “Notes of McTaggart, The Unreality of Time”, “Philosphy of space and time”