埋首於書堆中的駝鳥 ── 2015 篇

• How Nature Works: The science of self-organized criticality, Per Bak
• Classical Mechanics: The Theoretical Minimum, Leonard Susskind & George Hrabovsky
• Occupy, Noam Chomsky
• Zero to One: Notes on Startups, or How to Build the Future, Peter Thiel
• The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography, Simon Singh
• Pauli Lectures on Physics (Vol.5): Wave Mechanics, Wolfgang Pauli
• Quantum Mechanics: The Theoretical Minimum, Leonard Susskind & Art Friedman
• The Improbability Principle, David Hand
• The Social Contract, Jean-Jacques Rousseau
• 《思考學堂》梁光耀
• 《投行分析師的叛逆宣言》張化橋

埋首於書堆中的駝鳥 ── 2014 篇

• Philosophy 101: A Crash Course in the Principles of Knowledge, Reality, and Values, Paul Kleinman
• Antifragile: Things that Gain from Disorder, Nassim Nicholas Taleb
• Linked: How Everything Is Connected to Everything Else and What It Means for Business, Science, and Everyday Life, Albert-László Barabási
• David and Goliath: Underdogs, Misfits, and The Art of Battling Giants, Malcolm Gladwell
• Big Data: A Revolution That Will Transform How We Live, Work and Think, Viktor Mayer-Schönberger and Kenneth Cukier
• Economics: The User's Guide, Ha-Joon Chang
• The Rule of Law, Tom Bingham
• 《香港故事﹝1960's-1970's﹞邱良攝影選》邱良
• 《没有色彩的多崎作和他的巡礼之年》村上春樹﹝施小炜 譯﹞
• 《蛤蟆先生的希望》羅伯‧狄保德﹝張美惠 譯﹞(英語原著Counselling for Toads: A Psychological Adventure, Robert de Board)
• 《給青年科學家的信》愛德華‧奧斯本‧威爾森﹝王惟芬 譯﹞(英語原著Letters to a Young Scientist, Edward Osborne Wilson)
• 《政治的道德：從自由主義的觀點看》周保松

A Succinct and Faithful Description of Quantum Theory, then What?

The follow was excerpted from Section 7.3 in Chapter 5 of "Wholeness and the Implicate Order", a collection of David Bohm's essays:-

Every physical situation is[...]characterized by a wave function[...] This wave function is not directly related to the actual properties of an individual object, event, or process. Rather, it has to be thought of as a description of the potentialities within the physical situation. Different and generally mutually incompatible potentialities[...]are actualized in different experimental arrangements[...] In general, the wave function gives only a probability measure for the actualization of different potentialities in a statistical ensemble of similar observations carried out under a specified conditions, and cannot predict what will happen in detail in each individual observation[...] In quantum theory it has no meaning to discuss the actual state of a system apart from the whole set of experimental conditions which are essential to actualize this state.

And from Section 7.4 in Chapter 5:-

[...W]ave equation[...]is linear[...] Such linearity of equations[...]allows us to regard 'state vectors' as having a kind of autonomous existence[...] This complete autonomy of the 'quantum state' of a system is supposed to hold only when it is not being observed. In an observation, it is assumed that we have to do with two initially autonomous systems that have come into interaction. One of these is described by the 'state vector' of the observed object and the other by the 'state vector' of the observing apparatus.//In the consideration of this interaction, certain new features are introduced which correspond to allowing for the possibility of actualizing the observed system's potentialities at the expense of others that cannot be actualized at the same time.

What a succinct and faithful description of quantum theory!

As Schrödinger's cat illustrates, 'reduction of wave function' is, indeed, odd and incomprehensible. I previously had thought the so-called 'reduction of wave function' be merely a metaphor of 'the observer's getting known of the truth'. Surely, the Schrödinger's cat can only be either dead or alive at any time. Common sense tells that there is no dead-alive mixed state being a linear combination of the dead state and the alive state. It is only the knowledge of the observer that matters - the observer does not know the outcome (dead or alive) until the chamber containing the cat is opened. In this sense, 'wave function' is a representation of the observer's knowledge instead of a true physical entity of the observed. However, if wave function is 'knowledge', how can interference take place? I have no idea.

Apart from the Schrödinger's cat problem, I have been messed up most by quantum entanglement. Pursuant to the theory of relativity, the speed of light is ultimate that transmission of information cannot exceed. However, it was said that the instantaneous quantum entanglement had truly been observed in experiments.

Bohm put forth the notion of 'hidden variables' (something 'sub-quantum') and claimed that it could explain the essential features of quantum mechanics. Yet, how can the Schrödinger's cat problem be resolved? How can quantum entanglement be explained?

Bohm introduced the theory of holomovement:

[...A] total order is contained, in some implicit sense, in each region of space and time[...] Different pictures would look indistinguishable and yet have different implicate orders, which differences would be revealed when they were explicated[...] Generally speaking, the laws of physics have thus far referred mainly to the explicate order. (excerpted from Section 3 in Chapter 6)

[...W]hat 'carries' an implicate order is the holomovement, which is an unbroken and undivided totality[...T]he holomovement is undefinable and immeasurable. (excerpted from Section 4 in Chapter 6)

With a multi-dimensional holomovement, quantum entanglement is well explained:

[...N]on-local, non-causal relationship of distant elements can be understood by regarding each of the 'particles' constituting a system as a projection of a 'higher-dimensional' reality, rather than as a separate particle, existing together with all the others in a common three-dimensional space. (excerpted from Section 4 in Chapter 7)

Bohm further enriched his theory by regarding the holomovement (which is primary, self-existent and universal) as 'life implicit', and "inanimate matter be a secondary, derivative, and particular abstraction from the holomovement":-

[...W]e do not fragment life and inanimate matter, nor do we try to reduce the former completely to nothing but an outcome of the latter. (excerpted from Section 6 in Chapter 7)

Is it talking about life and inanimate matter be different projections of a multi-dimensional being in the holomovement? Should we take that Schrödinger's cat be actually "alive-and-dead": whether it is "alive" or "dead" in our ordinary sense merely depends on what projection would be captured in that particular instance of holomovement when the observation is made?

Perhaps we should even not be surprised if we see Schrödinger's cat had become Pavlov's dog after the chamber is opened. They are merely different projections of a superdimensional being, right?

The lesson that I have learnt from this book is that: When you are introduced with something said to be "undefinable and immeasurable", DON'T ASK!

H-D 方法

先前談過 D-N 模型﹝deductive-nomological model﹞，今回再論 H-D 方法﹝hypothetico-deductive method，在網上找到的中文翻譯為「假說演繹法」﹞。H-D 方法旨在將發展科學理論的過程程序化，有說這方法早於十九世紀初經已出現。根據 H-D 方法，科學理論是依以下程序發展出來的：

1. 憑觀測及經驗訂出要解釋的事件；
2. 嘗試為解釋該事件構想出一個假說﹝hypothesis﹞；
3. 將假說套用到其他事件，透過演繹邏輯﹝deductive logic﹞得出預測﹝prediction﹞；
4. 將預測與實情作比較，若預測符合實情，假說便得以驗證﹝verified﹞，並可將其視為可接受的理論；若預測與實情不符，假說便遭否證﹝falsified﹞，那便需對假說作出修正，甚至乎重新構想另一個新的假說，再重複過程的第三及第四步，如是者直至假說得以驗證。

要注意假說一般是不可能透過邏輯構想出來的，正如 Karl Popper 在 The Logic of Scientific Discovery ﹝《科學發現的邏輯》﹞中提到：

[...T]here is no such thing as a logical method of having new ideas, or a logical reconstruction of this process. My view may be expressed by saying that every discovery contains 'an irrational element', or 'a creative intuition'[...] (p.8)

H-D 方法有不少疑難，它既不能讓人分辨某理論是「定律」﹝law﹞還是「全稱推廣」﹝universal generalization﹞，亦導致「 烏鴉悖論」﹝The Raven Paradox﹞；Stanford Encyclopedia of Philosophy【Laws of Nature】對前者說明得很詳細， William Bechtel 在 Philosophy of Science: An Overview for Congnitive Science 第二章將後者解釋得很清楚：

[...A] law statement of the form

For all x, if x is F, then x is G
is logically equivalent to the statement

For all x, if x is not G, then x is not F.
If F stands for raven and G for black, then the law "All ravens are black" (e.g., for all x, if x is a raven, then it is black) is logically equivalent to "All things that are not black are not ravens" (e.g. For all x, if x is not black, then it is not a raven). To test the first statement, the H-D model would lead us to examine ravens to see if they are black. The more black ravens we encounter, the greater support for the law (as long as we do not encounter raven that are not black). But the form to which it is logically equivalent only requires us to examine things that are not black and test the prediction that these things will not be ravens. Every nonblack object that you see that is not a raven will confirm that putative law. So you can sit in the room you are now in and test the law that all ravens are black by making sure all the nonblack objects in the room are not ravens. Something clearly seems to have gone wrong! (p.26-27)

此外，傳統的 H-D 方法在測試理論方面﹝過程的第四步﹞不夠全面。Karl Popper 在《科學發現的邏輯》第三節提出測試理論可循四個方向進行：

We may if we like distinguish four different lines along which the testing of a theory could be carried out. First there is the logical comparison of the conclusions among themselves, by which the internal consistency of the system is tested. Secondly, there is the investigation of the logical form of the theory, with the object of determining whether it has the character of an empirical or scientific theory, or whether it is, for example, tautological. Thirdly, there is the comparison with other theories, chiefly with the aim of determining whether the theory would constitute a scientific advance should it survive our various tests. And finally, there is the testing of the theory by way of empirical applications of the conclusions which can be derived from it. (p.9)

上述最後一個方向即傳統的 H-D 方法的第四步。

Karl Popper 強調縱然理論得到事實支持，亦只是暫時可信，難保日後可能會被推翻：

It should be noticed that a positive decision can only temporarily support the theory, for subsequent negative decisions may always overthrow it. (p.10)

正如他所言：

[...N]o matter how many instances of white swans we may have observed, this does not justify the conclusion that all swans are white. (p.4)

這便是「黑天鵝問題」﹝The Black Swan Problem﹞。Karl Popper 對「黑天鵝」的關注促使他主張科學家檢測理論應採「否證法」﹝falsification﹞ ── 即 modus tollens ── 以否定理論為目標尋找證據；而非「驗證法」﹝verification﹞ ── 即 modus ponens ── 以肯定理論為目標尋找證據。

其實，可追溯「最先」提出黑天鵝問題的不是 Karl Popper，更不是《黑天鵝》﹝The Black Swan﹞的作者 Nassim Nicholas Taleb﹝他提出的「黑天鵝事件」有別的定義﹞，而是懷疑實證主義者大衛‧休謨﹝David Hume，1711-1776﹞：

In his Treatise on Human Nature, the Scots philosopher David Hume posed the issue in the following way (as rephrased in the now famous black swan problem by John Stuart Mill): No amount of observations of a white swan can allow the inference that all swans are white, but the observation of a single black swan can refute that conclusion. (摘錄自Fooled by Randomness, p.117)

噢！講完烏鴉又講天鵝，難道哲學家都喜歡鳥？


參考資料：

• Wikipedia【Hypothetico-deductive model】
• The Logic of Scientific Discovery, Karl Popper, Routledge Classics 2002, ISBN 978-0-415-27844-7
• Stanford Encyclopedia of Philosophy【Laws of Nature】
• Philosophy of Science: An Overview for Congitive Science, William Bechtel
• Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets, Nassim Nicholas Taleb, Penguin Books 2004, ISBN 978-0-141-03274-0
• The Black Swan: The Impact of the Highly Improbable, Nassim Nicholas Taleb, Penguin Books 2007, ISBN 978-0-141-03459-1

典範轉移

"Paradigm shift"﹝中文譯作「典範轉移」﹞這個詞組經常遭人濫用，尤其在商界，普普通通的一個新概念就揚稱是 paradigm shift，好比職場中的 title inflation ── 連掃地阿姐都變了做 "public hygiene specialist"。

"Paradigm shift" 這個詞組其實源自一本書 ── The Structure of Scientific Revolutions ﹝《科學革命的結構》﹞，作者是 Thomas Kuhn ，他原本是物理學家，後來醉心研究科學史，從中有所領悟，並於 1962 年寫成該書，提出甚具哲學意義、且顛覆性的見解。

現在在書店買得到的英文版多是五十周年紀念版，比起之前的第三版，該版加了 Ian Hacking 所著的引言。只因我喜歡原汁原味，不含雜質，為買 1996 年出版的第三版逛了多間書店，幸好在銅鑼灣的誠品找到一本。

據 Thomas Kuhn 所言，科學發展不是知識的持續累積，而是一個接一個的典範﹝paradigm﹞，從一個典範過渡至另一個典範的過程謂之「典範轉移」﹝paradigm shift﹞，促成典範轉移的是「危機」﹝crisis﹞以及隨之而來的「科學革命」﹝scientific revolution﹞。

典範是「常態科學」﹝normal science﹞發展的歷程，在一個典範之中，科學家普遍認為某些認知是真理，他們以這些認知為基礎進一步以「解答疑問」﹝puzzle-solving﹞的形式探索大自然及解釋自然現象，知識持續累積，科學得以平穩發展。在潛移默化中，他們做實驗的方法及所用的儀器、量度的標準，以至解釋實驗結果的理論都是基於這些認知制定出來，而課本及學校所教授的亦是這些認知，沒有人會懷疑這些認知的真確性；縱然某些發現與這些認知有抵觸，世人亦只會抱懷疑態度來看待這些發現，甚至將其視為「異象」﹝anomalies﹞。

當越來越多「異象」出現令越來越多科學家懷疑他們原有的認知，典範便陷入「危機」；可是部分科學家仍對他們的認知充滿信心，並認定遲早可以以現有的認知，藉「常態科學」的發展找出解釋「異象」的方案。

有科學家成功以新的認知解釋「異象」，新的認知獲得越來越多科學家的注意及認同，掀起一場「科學革命」，而隨著時光流逝，仍堅持舊認知的「死硬派」相繼逝世，舊的認知遭摒棄、遺忘、改寫，典範轉移完成。在新的典範之中，科學家普遍認為新的認知才是真理，在新的認知之下，他們對舊的觀測結果、概念、定義甚至是科學詞彙都有了新的理解，課本亦遭改寫。新一代的科學家毫不懷疑地認為這些認知是真理，並以此為基礎進一步探索大自然，新的知識又在「常態科學」的步伐下持續累積，科學再次得以平穩發展 …… ，直至另一個典範轉移發生。

在書中，Thomas Kuhn 多次以 Gestalt Switch 來解釋 paradigm shift；但又教人注意兩者其實不盡相同，例如：

[...A] process that involves "handling the same bundle of data as before, but placing them in a new system of relations with one another by giving them a different framework." Others who have noted this aspect of scientific advance have emphasized its similarity to a change in visual gestalt: the marks on paper that were first seen as a bird are now seen as an antelope, or vice versa. That parallel can be misleading. Scientists do not see something as something else; instead, they simply see it. [...T]he scientist does not preserve the gestalt subject's freedom to switch back and forth between ways of seeing. Nevertheless, the switch of gestalt, particularly because it is today so familiar, is a useful elementary prototype for what occurs in full-scale paradigm shift. (p.85)

The subject of a gestalt demonstration knows that his perception has shifted because he can make it shift back and forth repeatedly while he holds the same book or piece of paper in his hands. Aware that nothing in his environment has changed, he directs his attention increasingly not to the figure (duck or rabbit) but to the lines on the paper he is looking at. Ultimately he may even learn to see those lines without seeing either of the figures, and he may then say[...]that it is these lines that he really sees but that he sees them alternately as a duck and as a rabbit. [...]Unless there were an external standard with respect to which a switch of vision could be demonstrated, no conclusion about alternate perceptual possibilities could be drawn. [//]With scientific observation, however, the situation is exactly reversed. The scientist can have no recourse above or beyond what he sees with his eyes and instruments. If there were some higher authority by recourse to which his vision might be shown to have shifted, then that authority would itself become a source of problems[...]. The same sorts of problems would arise if the scientist could switch back and forth like the subject of the gestalt experiments. [...]In the sciences, therefore, if perceptual switches accompany paradigm changes, we may not expect scientists to attest to these changes directly. [...]Rather we must look for indirect and behavioral evidence that the scientist with a new paradigm sees differently from the way he had seen before. (p.114-115)

全書連一幅插圖也沒有，為了解 Gestalt switch，在亙聯網用搜尋器搜了一番，雖然找不到以鳥及羚羊﹝bird and antelope﹞為題材的錯覺畫，但就找到「鴨與兔」﹝如下﹞，看過必能體驗 Gestalt switch。有說「鴨與兔」是心理學家 Joseph Jastrow 於 1888 年提出的：
﹝轉載及改遍自《維基百科》【Rabbit-duck illusion】﹞
Thomas Kuhn 的學說有以下的深層次含意，亦是備受爭議之處：

整體論﹝holism﹞
不同的典範有不同的架構，就連表面上客觀的觀測結果都會在不同的理論及觀念之下而有不同的理解﹝theory-laden data﹞，典範之間根本不存在共通的語言，故不可能共融﹝incommensurate﹞，新典範的出現宣告舊典範的覆亡。

相對主義﹝relativism﹞
在不同的典範之中，科學家對「真理」有不同的理解。至於那個「真理」才是真理？我們卻無從得知。絕對的真理並不存在；真理是相對的。

科學的非理性﹝irrationality﹞
世上不存在選擇典範的規則系統，轉移與否以及轉移至哪一個典範取決於科學界對不同典範「解答疑問」﹝puzzle-solving﹞的潛力的評估。此外，由於絕對的真理不存在，探索真理亦難說得上是科學發展的目標，科學的發展正如達爾文在《進化論》提出的生物進化過程，生物隨自然環境的轉變而進化，科學則在不同的典範中向不同的「真理」邁進，沒有永恆的目標。


參考資料：

• The Structure of Scientific Revolutions, Third Edition, Thomas S. Kuhn, The University of Chicago Press, ISBN-10: 0-226-45808-3
• Philosophy of Science: A Very Short Introduction, Samir Okasha, Oxford, ISBN: 978-0-19-280283-5

埋首於書堆中的駝鳥 ── 2013 篇

• 《蔡瀾四談日本》蔡瀾﹝重閱﹞ The Structure of Scientific Revolutions (3rd edition), Thomas S. Kuhn
• Harvard Business Review on Corporate Strategy, Harvard Business School Press
• Creating Corporate Advantage, David J. Collis and Cynthia A. Montgomery
• Competing on Resources: Strategy in the 1990s, David J. Collis and Cynthia A. Montgomery
• Desperately Seeking Synergy, Michael Goold and Andrew Campbell
• The End of Corporate Imperialism, C.K. Prahalad and Kenneth Lieberthal
• Beyond Greening: Strategies for a Substainable World, Stuart L. Hart
• Why Focused Strategies May Be Wrong for Emerging Markets, Tarun Khanna and Krishna Palepu
• Competing on Capabilities: The New Rules of Corporate Strategy, George Stalk, Philip Evens and Lawrence E. Shulman
• Corporate Strategy: The Quest for Parenting Advantage, Andrew Campbell, Michael Goold and Marcus Alexander
• The Road To Serfdom, F.A. Hayek
• Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics, Craig F. Bohren
• What Light Through Yonder Window Breaks?: More Experiments in Atmospheric Physics, Craig F. Bohren
• The Art of Thinking Clearly, Rolf Dobelli
• Wholeness and the Implicate Order, David Bohm
• The Signal and the Noise, Nate Silver
• Sway: The Irresistible Pull of Irrational Behaviour, Ori Brafman and Rom Brafman
• Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel, Michio Kaku

D-N 模型

Karl Popper 曾提及他認為存在同樣適用於描述自然科學與社會科學發展的統一方法。索羅斯﹝George Soros﹞不同意，他認為人的感知會影響事態，並破壞 "deductive-nomological model" 之中預測與解釋的對稱性，繼而否定統一方法的存在。

似乎索羅斯是拋錯書包。事實上，從《歷史定論主義的窮困》﹝The Poverty of Historicism﹞第 29 節﹝121 頁﹞可知 Karl Popper 所指的統一方法並非 "deductive-nomological model" ，而是 "hypothetical-deductive method"：

[...]The methods always consist in offering deductive causal explanations, and in testing them (by way of predictions). This has sometimes been called the hypothetical-deductive method, or more often the method of hypothesis[...]

在此先談 "deductive-nomological model"，日後有時間再論 "hypothetical-deductive method"。

"Deductive-nomological model" 簡稱 "D-N model"， 亦稱為 "covering law model"，中文有的譯作「演繹‧法則模型」。為簡便，以下將其稱為 D-N 模型。

D-N 模型旨在將解釋事件的科學方法邏輯化，根據 D-N 模型，解釋某事件便是以已知的事實作為「前題」﹝premises﹞，並透過演繹邏輯﹝deductive logic﹞推理出事件，而那些前題便是事件的解釋。D-N 模型要求所有前題均能夠被實証﹝empirically testable﹞，且必須真確，而當中至少一項是定律﹝law﹞。例如要解釋「釘子會生鏽」──

前題一：釘子是用鐵造的﹝事實 C﹞
前題二：鐵會生鏽﹝定律 L﹞
結論：釘子會生鏽﹝事件 E﹞

D-N 模型還有以下特點：

1. 解釋與預測是對稱的 ── 若事件還未發生﹝或未知﹞，得到的結論便是個「預測」，箇中引用的前題在事後便可用來解釋事件，故能預測便等於能解釋，反之亦然；
   
2. 漠視因果關係 ── 沒要求定律描述的是從因到果的過程。

另一方面，D-N 模型亦存在兩大疑難，分別是「不對稱疑難」﹝the problem of asymmetry﹞及「不相關疑難」﹝the problem of irrelevance﹞。某程度上這兩大疑難的出現皆因 D-N 模型漠視了因果關係。

「不對稱疑難」
試考慮一支垂直的旗杆，若知道旗杆高度﹝前題一﹞及太陽仰角﹝前題二﹞便可根據光行直線﹝前題三﹞及三角幾何﹝前題四﹞預測旗杆影子的長度﹝事件﹞，前題一、二是已知的事實，前題三、四是已知的定律；事件既可根據這些前題透過演繹邏輯預測出來，這些前題亦可視為對事件的解釋。倘若將影子長度視為前題一，而前題二、三、四不變，那麼預測出的事件便是旗杆高度；但是，將影子長度﹝加上其他前題﹞說成是對旗杆高度的解釋就怎樣都說不通！那旗杆有多高是人為既定的嘛！

「不相關疑難」
根據「吃了避孕藥的人不會懷孕」﹝前題一﹞、「強仔是人」﹝前題二﹞及「強仔吃了避孕藥」﹝前題三﹞，透過演繹法便可預測強仔不會懷孕；強仔固然不會懷孕，但這些前題其實與強仔不會懷孕沒有關係，亦不是強仔不會懷孕的正確解釋。強仔是男人才是他不會懷孕的真正原因嘛！

大部份文獻稱 D-N 模型是 Carl Hempel 與 Paul Oppenheim 提出的，有人更將 D-N 模型稱為 Hempel-Oppenheim 模型，原因是 Hempel 與 Oppenheim 於 1948 年發表過一篇題為 "Studies in the Logic of Explanation" 的文章，對上述解釋事件的科學方法作出了詳細分析，以下摘錄自該文章的引言：

To explain the phenomena in the world of our experience, to answer the question "why?" rather than only the question "what?", is one of the foremost objectives of all rational inquiry; and especially, scientific research in its various branches strives to go beyond a mere description of its subject matter by providing an explanation of the phenomena it investigates. While there is rather general agreement about this chief objective of science, there exists considerable difference of opinion as to the function and the essential characteristics of scientific explanation. In the present essay, an attempt will be made to shed some light on these issues by means of an elementary survey of the basic pattern of scientific explanation and a subsequent more rigorous analysis of the concept of law and of the logical structure of explanatory arguments.

事實上，Karl Popper 早在 1934 年已提出過類似 D-N 模型的構思，下文摘錄自《科學發現的邏輯》﹝The Logic of Scientific Discovery﹞第 12 節：

To give a causal explanation of an event means to deduce a statement which describes it, using as premises of the deduction one or more universal laws, together with certain singular statements, the initial conditions. […]We have thus two different kinds of statement, both of which are necessary ingredients of a complete causal explanation. They are (1) universal statement, i.e. hypotheses of the character of natural laws, and (2) singular statements, which apply to the specific event in question and which I shall call 'initial conditions'. It is from universal statements in conjunction with initial conditions that we deduce the singular statement. [...]We call this statement a specific or singular prediction.

注意 Popper 提的是 "causal explanation" 以及前題中的事實是 "initial conditions"，顯示 Popper 著重因果關係對解釋事件的重要性。

Hempel 與 Oppenheim 在他們的文章中亦提過 "causal explanation"；但他們提及的 "causal" 卻不是「前因後果」， 而是 "non-statistical"，那只是說明 D-N 模型中的事件是決定性的﹝deterministic﹞：

The type of explanation which has been considered here so far is often referred to as causal explanation. If E describes a particular event, then the antecedent circumstances described in the sentences C₁, C₂, …, C_k may be said jointly to "cause" that event, in the sense that there are certain empirical regularities, expressed by the laws L₁, L₂, …, L_r, which imply that whenever conditions of the kind indicated by C₁, C₂, …, C_k occur, an event of the kind described in E will take place. Statements such as L₁, L₂,…, L_r, which assert general and unexceptional connections between specified characteristics of events, are customarily called causal, or deterministic, laws. They are to be distinguished from the so-called statistical laws which assert that in the long run, an explicitly stated percentage of all cases satisfying a given set of conditions are accompanied by an event of a certain specified kind.

邏輯實證主義﹝logical positivism﹞以邏輯及實證為本，而因果關係是無法證實的，D-N 模型對因果關係的漠視，充分反映 Hempel 與 Oppenheim 信奉的是大衛‧休謨﹝David Hume﹞式的懷疑實證主義﹝skeptical empiricism﹞──「病態般」的多疑。以下摘錄自 Samir Okasha 的 Philosophy of Science: A Very Short Introduction：

For Hempel subscribed to a philosophical doctrine known as empiricism, and empiricists are traditionally very suspicious of the concept of causality. Empiricism says that all our knowledge comes from experience. David Hume[…]was a leading empiricist, and he argued that it is impossible to experience causal relations. So he concluded that they don't exist – causality is a figment of our imagination! […]Most empiricists have not accepted this startling conclusion outright. But as a result of Hume's work, they have tended to regard causality as a concept to be treated with great caution. So to an empiricist, the idea of analysing the concept of explanation in terms of the concept of causality would seem perverse. If one's goal is to clarify the concept of scientific explanation, as Hempel's was, there is little point in using notions that are equally in need of clarification themselves. And for empiricists, causality is definitely in need of philosophical clarification. So the fact that the covering law model makes no mention of causality was not a mere oversight on Hempel's part.

參考資料：

• The Poverty of Historicism, Karl Popper, Routledge Classics 2002, ISBN 0-415-27846-5
• The Alchemy of Finance: Reading the Mind of the Market, George Soros, John Wiley & Sons, ISBN 0-471-04206-4
• The Logic of Scientific Discovery, Karl Popper, Routledge Classics 2002, ISBN 978-0-415-27844-7
• Philosophy of Science: A Very Short Introduction, Samir Okasha, Oxford, ISBN: 978-0-19-280283-5
• Studies in the Logic of Explanation, Philosopy of Science 15 (1948): 135-175, Hempel, Carl G. & Oppenheim, Paul

烏托邦工程的敗筆

烏托邦工程﹝Utopian engineering﹞旨在按照既定的藍圖將整個社會改造。在《歷史定論主義的窮困》﹝The Poverty of Historicism﹞，Karl Popper 提出了獨特的見解，他認為烏托邦工程只是一場「春秋大夢」﹝an Utopian dream﹞，因為烏托邦工程奉行「整體論」﹝holism﹞，而整體論本身已欠妥當：

1. 不著眼於什麼特質令社會成為有組織的個體，卻硬要將社會內的一切視為一個「整體」來看待，如此「全方位」的視角實質上等同沒有視角，陷於空泛和不切實際 ──

There is a fundamental ambiguity in the use of the word 'whole'. [...]It is used to denote (a) the totality of all the properties or aspects of a thing, and especially of all the relations holding between its constituent parts, and (b) certain special properties or aspects of the thing in question, namely those which make it appear an organized structure rather than a 'mere heap'. [...]The fact that wholes in sense (b) can be studied scientifically must therefore not be appealed to in order to justify the entirely different claim that wholes in sense (a) can be so studied. The latter claim must be rejected. If we wish to study a thing, we are bound to select certain aspects of it. It is not possible for us to observe or to describe a whole piece of the world, or a whole piece of nature; in fact, not even the smallest whole piece may be so described, since all description is necessarily selective. It may even be said that wholes in sense (a) can never be the object of any activity, scientific or otherwise. (p.70-71)

2. 對「摸著石頭過河」式的方法﹝piecemeal approach﹞存有偏見，蔑視制度的極限，試圖改變人性﹝「洗腦」？﹞來迎合藍圖中的理想國，削足適履，違背科學原則 ──

   [W]hile the piecemeal engineer can attack his problem with an open mind as to the scope of the reform, the holist cannot do this; for he has decided beforehand that a complete reconstruction is possible and necessary. [...]It prejudices the Utopianist against certain sociological hypotheses which state limits to institutional control; for example, the one expressing the uncertainty due to the personal element, the 'human factor'. By a rejection a priori of such hypotheses, the Utopian approach violates the principles of scientific method. On the other hand, problems connected with the uncertainty of the human factor must force the Utopianist[...]to try to control the human factor by institutional means, and to extend his programme so as to embrace not only the transformation of society, according to plan, but also the transformation of man. [...]For it substitutes for his demand that we build a new society, fit for men and women to live in, the demand that we 'mould' these men and women to fit into his new society. This, clearly, removes any possibility of testing the success or failure of the new society. [...]The holistic approach is incompatible with a truly scientific attritude. (p.63-64)

3. 中央集權無助廣集知識，當權者在欠缺知識的情況下，唯有透過消除人與人之間的分歧﹝傾向極權！﹞，從而將問題簡化；但由於人民自由表達思想的權利被剝奪，結果更不利於當權者拮取知識 ──

The holistic planner overlooks the fact that it is easy to centralize power but impossible to centralize all that knowledge which is distributed over many individual minds, and whose centralization would be necessary for the wise wielding of centralized power. [...]Unable to ascertain what is in the minds of so many individuals, he must try to simplify his problems by eliminating individual differences: he must try to control and stereotype interests and beliefs by education and propaganda. But his attempt to exercise power over minds must destroy the last possibility of finding out what people really think, for it is clearly incompatible with the free expression of thought, especially of critical thought. Ultimately, it must destroy knowledge; and the greater the gain in power, the greater will be the loss of knowledge. (p.83)

可以說，整體論是烏托邦工程的敗筆。

參考資料：

• The Poverty of Historicism, Karl Popper, Routledge Classics 2002, ISBN 0-415-27846-5

續談「自反理論」

昨天提過索羅斯的「自反理論」與「金融煉金術」。「金融煉金術」只是「自反理論」引申出來，應用於金融市場上的操作方法，其用途當然是賺錢。其實「煉金術」的用途不只限於在金融市場賺錢那麼「低檔」的範疇，在政治層面以至市場推廣方面都用得着；而除了引申出「煉金術」，「自反理論」還有更深層次的啟示，否則索羅斯又豈能稱得上是個哲學家。「自反理論」的啟示還包括：

1. 「演繹‧法則模型」﹝Deductive-nomological model﹞ 並不普遍適用於社會科學 ── 否定 Karl Popper 「統一方法」﹝unity of method﹞的想法 ──

The idea that there is a fundamental difference in the subject matter of the natural and social sciences has not been generally recognized. On the contrary, Karl Popper[...]enuciated what he called the "doctrine of the unity of science"; that is, the same methods and criteria apply in both the natural and social sciences. Although it has not been universally accepted, it has not been conclusively refuted either. I shall try to do so here[...]For this purpose I am invoking Karl Popper's scheme of scientific method, described in technical terms as the "deductive-nomological," or "D-N," model[...]An essential conditon [of the model] is that the content of the statements should exist in total isolation from the statements that are made about them[...T]he initial and final conditions should consist of facts which are amendable to scientific observation and the generalizations should have universal validity[...]If thinking is included, the conditions are not amendable to scientific observation, because only the effects of the participants' thinking can be observed, not the process itself. If the thinking process is excluded and only its effects are admitted as evidence, the universal validity of scientific generalizations is destroyed because a given set of conditions is not necessarily preceded or succeeded by the same set every time[...]In either cases, the D-N model breaks down. (p.35-37)

2. 否定經濟學理論的「理性行為」假設 ── 經濟學是空中樓閣 ──

Economics seeks to be a science. Science is supposed to be objective and it is difficult to be scientific when the subject matter, the participant in the economic process, lacks objectivity. [...]Economic theory tries to sidestep the issue by introducing the assumption of rational behavior. People are assumed to act by choosing the best of available alternatives, but somehow the distinction between perceived alternatives and facts is assumed away. The result is a theoretical construction of great elegance that resembles natural science but does not resemble reality. (p.11-12)

3. 市場不會趨向平衡，藉市場分配資源的做法並非最佳 ── 放任﹝laissez faire﹞政策不可取，市場須要適度監控 ──

[F]inancial markets as well as macro-economic developments[...]exhibit no tendency towards equilibrium. [...M]arkets tend towards excesses, which sooner or later become unsustainable, so that they are eventually corrected. Equilibrium is supposed to ensure the optimum allocation of resources. If markets do not tend towards equilibrium, the main argument that has been used in favor of the market mechanism loses its validity: we have no grounds for believing that markets optimize anything. (p.317)

索羅斯認為市場須要適度監控，但他不贊同計劃經濟 。雖然市場未盡完美，但他認為總較沒有市場好 ──

[C]entrally planned economies which, in revulsion against the deficiencies of market economies, have eschewed the use of the pricing mechanism. Output has to be measured in physical quantities, and the distortions are far worse than the excesses of the market. [...M]arket mechanism[...]is the worst system of allocating resources except for all the others. (p.318)

至於監控何謂適度，則取決於對不穩定的可接受程度，視乎判斷而定 ──

The prevention of excessive instability is[...]a necessary condition for the smooth functioning of the market mechanism. [...]How much instability is excessive is a matter of juidgment. [...]The sooner we recognize that some kind of regulation is necessary in order to maintain stability, the better our chances of preserving the benefits of a nearly free market system. (p.322-323)

4. 社會的政治模式在極權與自由之間擺動，難以達到平衡點 ──

Each form of social organization was found wanting in something that could be found only in its opposite: totalitarian society lacked freedom; Open Society lacked stability. But given our innate bias, a stable equilibrium between the two is just as unlikely to be attained as a stable equilibrium in a free market. Sentiment is likely to swing in one direction or the other. (p.323)

參考資料：

• The Alchemy of Finance: Reading the Mind of the Market, George Soros, John Wiley & Sons, ISBN 0-471-04206-4

「自反理論」與「金融煉金術」

索羅斯﹝George Soros﹞是舉世知名的「大炒家」；然而，看過他的著作《金融煉金術》﹝The Alchemy of Finance﹞之後，才意識到他可稱得上是個「哲學家」。他提出「自反理論」﹝The Theory of Reflexivity﹞，並以金融市場為實驗室，以價格走勢來測試他的理論 ──

[I]t is possible to see financial markets as a laboratory for testing hypotheses, albeit not strictly scientific ones. (p.14)

「自反理論」並非狹義的技術分析或基本分析理論，而是更為廣義的哲學或社會學理論。雖然 Popper 早已意會到 Oedipus effect ── 亦即「自我應驗預言」﹝self-fulfilling prophecy﹞ 或「自我失效預言」﹝self-defeating prophecy﹞ ── 會令社會事件難以預測，但他仍深信存在同樣適用於描述自然科學與社會科學發展的「統一方法」﹝unity of method﹞。索羅斯不贊同 Karl Popper 的想法 ，他有見社會事件會涉及人，人的感知便會影響事態，事態又會反過來影響人的感知，而往往人的感知又存有偏見，導致問題 ──

I was greatly influenced at the time by Karl Popper's ideas on scientific method. I accepted most of his views, with one major exception. He argued in favour of what he called 'unity of method' ── that is, the methods and criteria that apply to the study of natural phenomena also apply to the study of social events. I felt that there was a fundamental difference between the two: the events studied by the social sciences have thinking participants; natural phenomena do not. The participants' thinking creates problems that have no counterpart in natural science. (p.11-12)

When events have thinking participants, the subject matter is no longer confined to facts but also includes the participants' perceptions. The chain of causation does not lead directly from fact to fact but from fact to perception and from perception to fact. This would not create any insuperable difficulties if there were some kind of correspondence or equivalence between facts and perceptions. Unfortunately, that is impossible because the participants' perceptions do not relate to facts, but to a situation that is contingent on their own perceptions and therefore cannot be treated as fact. (p.12)

I believed that the participants' bias is the key to an understanding of all historical processes that have thinking participants. (p.16)

他將人的感知與事態的雙向反饋﹝double feedback mechanism﹞稱為「自反作用」﹝reflexivity﹞： 而所謂的問題就是事態偏離平衡點及變得不穩定，即是從偏離平衡點的一方突然倒向另一方，且無法預測。

套用到金融市場，「不穩定」就是 boom and bust。索羅斯悟出：要在金融市場穩操勝券，須準確預期人對世事普遍會有什麼期望，而非真實世界會有什麼發生。他將此類操作稱為「煉金術」﹝alchemy﹞──

Scientific method seeks to understand things as they are, while alchemy seeks to bring about a desired state of affairs. To put it another way, the primary objective of science is the truth ── that of alchemy, operational success. In the sphere of natural phenomena, there is no distinction between the two objectives. Nature obeys laws that operate independently of whether they are understood or not; the only way man can bend nature to his will is by understanding and applying these laws. [...]But social phenomena are different: they have thinking participants. Events do not obey laws that operate independently of what anybody thinks. On the contrary, the participants' thinking is an integral part of the subject matter. This creates an opening for alchemy that was absent in the sphere of natural science. Operational success can be achieved without attaining scientific knowledge. By the same token, scientific method is rendered just as ineffectual in dealing with social events as alchemy was in altering the character of natural substances. [...]Financial success depends on the ability to anticipate prevailing expectations and not real-world developments. [...]Market prices always express a prevailing bias, whereas natural science works with an objective criterion. Scientific theories are judged by the facts; financial decisions are judged by the distorted views of the participants. Instead of scientific method, financial markets embody the method of alchemy. (p.303-304)

或許你會認為索羅斯的「煉金術」與凱恩斯（John Maynard Keynes）的「鬥傻理論」﹝bigger fool theory﹞無異；在細節上，「煉金術」的重點在於識別可助長雙向反饋的條件，以股票市場為例，若然投資者的偏見不單令股價偏離合理值，且還影響到基本因素﹝例如因公司持有的股份價格上升而獲利、市值上升而有利拼購等﹞的話， boom/bust 就很可能會出現。更甚者，「煉金術司」還可施展「煉金術」，主動影響市場及其他投資者的感知，點石成金。

參考資料：

• The Alchemy of Finance: Reading the Mind of the Market, George Soros, John Wiley & Sons, ISBN 0-471-04206-4
• The Poverty of Historicism, Karl Popper, Routledge Classics 2002, ISBN 0-415-27846-5

歷史定論主義的窮困

以「爬」的速度看完 Karl Popper 的著作 The Poverty of Historicism﹝《歷史定論主義的窮困》﹞，薄薄的 149 頁，我看了整整一個月，還只是很粗略地看，理解到的只有點滴；但得著仍是相當多。

在書中，Popper 所謂的 'historicism' ﹝歷史定論主義﹞是指「試圖藉找出歷史發展的趨勢或韻律，從而預測未來社會發展」的一門社會科學 ──

An approach to the social sciences which assumes that historical prediction is their principal aim, and which assumes that this aim is attainable by discovering the 'rhythms' or the 'patterns', the 'laws' or the 'trends' that underlie the evolution of history. (p.3)

Popper 以邏輯反駁歷史定論主義 ──

1. The course of human history is strongly influenced by the growth of human knowledge[...]
2. We cannot predict, by rational or scientific methods, the future growth of our scientific knowledge[...]
3. We cannot, therefore, predict the future course of human history[...]
4. [...]There can be no scientific theory of historical development serving as a basis for historical prediction.
5. The fundamental aim of historicist methods is therefore misconceived; and historicism collapses.
(p.xii)

── ，指出歷史定論主義者錯誤地將趨勢﹝trends﹞當成全稱定律﹝universal laws﹞ ──

[T]he existence of trends or tendencies in social change can hardly be questioned. [...]But trends are not laws. A statement asserting the existence of a trend is existential, not universal. [...]And a statement asserting the existence of a trend at a certain time and place would be a singular historical statement, not a universal law. [...]while we may base scientific predictions on laws, we cannot[...]base them merely on the existence of trends. A trend[...]which has persisted for hundreds or even thousands of years may change within a decade, or even more rapidly than that. [...L]aws and trends are radically different things. (p.106)

Explained trends do exists, but their persistence depends on the persistence of certain specific initial conditions (which in turn may sometimes be trends)[...H]istoricists overlook the dependence of trends on initial conditions[...]Their confusion of laws with trends makes them believe in trends which are unconditional (and therefore general)[...](p.118)

── 及將歷史詮釋﹝historical interpretation﹞誤當成理論﹝theory﹞ ──

For in theoretical science laws act, amongst other things, as centres of interest to which observations are related. [...]In history the universal laws[...]cannot possibly fulfil this function. It must be taken over by something else. For undoubtedly there can be no history without a point of view; like the natural sciences, history must be selective[...] (p.138-139)

The only way out[...]is[...]consciously to introduce a preconceived selective point of view into one's history[...A]ll available evidence which has a bearing on our point of view should be considered carefully and objectively. (p.139)

We shall call such a selective point of view[...]a historical interpretation. (p.139-140)

Historicism mistakes these interpretations for theories[...They] do not see that there is necessarily a plurality of interpretations which are fundamentally on the same level of both suggestiveness and arbitrariness. [...]Instead, they present them as doctrines or theories[...] (p.140)

── ，並對歷史定論主義﹝尤其是馬克斯主義﹞，以及「烏托邦工程」﹝Utopian engineering﹞作出猛烈評擊，指烏托邦工程只是一場「春秋大夢」﹝an Utopian dream﹞。

在書中﹝§32﹞，Popper 提出 Institutional Theory of Progress ﹝發展的制度理論﹞，否定科學的客觀性並非單純依靠科學家持「客觀」的態度﹝因為態度是個人及內在的，既無法量度，亦難以在人與人之間作比較，根本無「客觀」可言﹞。Popper 認為科學的客觀性某程度上是基於社會制度﹝what is usually called 'scientific objectivity' is based, to some extent, on social institutions﹞，因為科學﹝及其客觀性﹞是建基於思想的自由競爭﹝free competition of thought﹞，須要民主的政治制度來維護 ──

Scientific method itself has social aspects. Science, and more especially scientific progress, are the results not of isolated efforts but free competition of thought. For science needs ever more competition between hypotheses and ever more rigorous tests. And the competing hypotheses need personal representation... This personal representation must be institutionally organized if we wish to ensure that it works. And these institutions have to be paid for, and protected by law. Ultimately, progress depends very largely on political factors; on political institutions that safeguard the freedom of thought: on democracy. (p.143)

If the growth of reason is to continue, and human rationality to survive, then the diversity of individuals and their opinions, aims, and purposes must never be interfered with. [...]Even the emotionally satisfying appealing for a common purpose, however excellent, is an appeal to abandon all rival moral opinions and the cross-criticisms and arguments to which they give rise. It is an appeal to abandon rational thought. (p.147)

Holistic control, which must lead to the equalization not of human rights but of human minds, would mean the end of progress. (p.147)

要知《歷史定論主義的窮困》的初稿在 1935 年完成，而 Popper 早在 1919-20 年已意識到歷史是不可預測的 ──

The fundamental thesis of this book ── that the belief in historical destiny is sheer superstition, and that there can be no prediction of the course of human history by scientific or any other rational methods ── goes back to thewinter of 1919-1920. The main outline was completed by 1935; it was first read, in January or February 1936, as a paper entitled 'The Poverty of Historicis'[...](Historical Note)

── ；那個時期正值俄國十月革命﹝1917﹞之後、第二次世界大戰爆發﹝1939﹞之前，共產主義的種子正在散播，當時世上不少人對「烏托邦工程」﹝Utopian engineering﹞奉若神明。

參考資料：

• The Poverty of Historicism, Karl Popper, Routledge Classics 2002, ISBN 0-415-27846-5

恍如隔世的森林﹝續﹞

想談一談重讀《挪威的森林》的感受﹝我看的是林少華翻譯的版本﹞：

一. 覺得永澤與渡邊談及外務省考試的對話相當精彩﹝65 至 67 頁﹞：
『「那你為什麼還要進外務省呢？」
「……不過最主要的理由是想施展一翻自己的拳腳。既然施展，就得到最廣大的天地裏去，那就是國家。我要嘗試一下在這臃腫龐大的官僚機構中，自己能爬到什麼地步，到底有多大本事。懂嗎？」
「聽起來有點像做遊戲似的。」
「不錯，差不多就是一種遊戲。我並沒有什麼權力欲金錢欲，真的。……有的只是好奇心，只是想在那廣闊無邊而險象環生的世界裏一顯身手擺了。」
「也沒有什麼理想之類的東西嗎？」
「當然沒有！」他說，「人生中無需那種東西，需要的不是理想，而是行為規範！」 …… 「嗯，永澤君，你的所謂人生規範是怎麼一種貨色？」
「你呀，肯定發笑的！」
「我不笑！」
「就是當紳士。」
我固然沒笑，但險些從椅子上滾落下來：「所謂紳士，就是那個紳士？」
「是的，就是那個紳士。」他說。
「那麼當紳士，是怎麼回事？要是有定義，可否指教一二？」
「紳士就是：所做的，不是自己想做之事，而是自己應做之事。」
「在我見過的人當中，你是最特殊的。」我說。
「在我見過的人裏邊，你是最地道的。」他說，隨後一個人掏腰包付了賬。』

── 不單止內容風趣幽默，還很有電影的感覺，有如鏡頭反覆指向永澤與渡邊。

二. 對渡邊對初美的情感感到不解﹝251 至 252 頁﹞：
『……但初美這位女性身上卻有一種強烈打動人心的力量，而那絕非是足以撼倒對方的巨大力量。她所發出的不過是微不足道的力，然而卻能引起對方心靈的共振。……我一直注視她，一直在思索她在我心中激起的這種感情震顫究竟是什麼東西，但直到最後也未能明了。

當我恍然領悟到其為何物的時候，已是十二三年以後的事了。……我猛然想起了初美，並且這時才領悟她給我帶來的心靈震顫究竟是什麼東西──它類似一種少年時代的憧憬，一種從來不曾實現而且永遠不可能實現的憧憬。這種直欲燃燒般的天真爛漫的憧憬，我在很早以前就已遺忘在什麼地方了，甚至很長時間裏我連它曾在我心中存在過都記不起了，而初美所搖撼的恰恰就是我身上長眠未醒的「我自身的一部分」。當我恍然大悟時，一時悲愴之極，幾欲涕零。……』

三. 對渡邊與玲子在阿美寮的一段對話﹝176 至 177 頁﹞：
『……「把病員和職員全部對換位置還差不多。」 …… 「我們的正常之處，」玲子說，「就在於自己懂得自己的不正常。」』

以及渡邊剛從阿美寮回東京後見到街上的光景﹝ 197 頁﹞：
『……面對如此光景，頭腦漸漸亂成一團，茫無頭緒。這到底算什麼呢？這紛亂雜陳的場面到底意味着什麼呢？』

── 感到相當妙。兩者皆指出「正常」與「不正常」的相對性，令人反思將思想或行為與眾不同的人歸類為「不正常」，將其標籤為「精神病人」，甚至禁錮他們的做法是否正確。似是在指出多數人盲目活在社會體制之下不懂反思，以及控訴社會對非主流思想的禁制與壓迫。

四. 就以下渡邊腦際中的話，產生了莫大的共鳴感：

「文章這種不完整的容器所能容納的，只能是不完整的記憶和不完整的意念。」﹝10 頁﹞
「或許我的心包有一層硬殼，能破殼而入的東西是極其有限的，所以我才不能對人一往情深。」﹝32 頁﹞
「我時不時向空間漂浮的光粒子伸出手去，但指尖什麼也觸不到。」﹝34 頁﹞

以下這句，更是妙不可言：
「我只消嗅一下書香，撫摸一下書頁，便油然生出一股幸福之感。」﹝35 頁﹞

日文原文：「その本の香りをかぎ、ページに手を触れているだけて、僕は幸せ​な気持ちになることができた。」

埋首於書堆中的駝鳥 ── 2012 篇

• 《「〈1Q84〉之後～」特集 ── 村上春樹 Long Interview 長訪談》
• 《從祖沖之的圓周率談起》華羅庚
• 《反轉腦袋投資學》王澤基
• 《官商同謀 ── 香港公義私利的矛盾》顧汝德﹝馬山、陳潤芝、蔡祝音 譯﹞
• 《藝康相機故事》伍振榮
• 《數位單眼相機的知識：精通攝影技術法則 161》
• 《盈動兼併香港電訊》馮邦彥
• 《Hong Kong Style 香港風格》胡恩威
• 『空の色と光の図鑑』斎藤文一・武田康男
• The Wisdom of Crowds: Why the many are smarter than the few, James Surowiecki
• Critical Mass: How one thing leads to another, Philip Ball
• What Money Can't Buy: The moral limits of markets, Michael Sandel
• A Random Walk Down Wall Street (5th edition), Burton Malkiel
• The Psychology of Investing, John R. Nofsinger
• The Ascent of Money: A Financial History of the World, Niall Ferguson
• The Alchemy of Finance: Reading the Mind of the Market, George Soros
• Six Not-so-easy Pieces, Richard Feynman
• The Poverty of Historicism, Karl Popper
• Philosophy of Science: A Very Short Introduction,Samir Okasha
• Philosophy of Science: An Overview for Cognitive Science, William Bechtel, Chapter 2 - Logical Positivism: The Received View in Philosophy of Science
• Obliquity: Why Our Goals Are Best Achieved Indirectly, John Kay

Wan Chai Market: Rediscovering Streamline Moderne Architecture, Lee Ho Yin and Lynne DiStefano

恍如隔世的森林

近日又回到村上的世界，將那本久擱在書架上的《挪威的森林》重閱了一遍。那本書邊都已發黃的書，書頁間仍夾着一張《花與愛麗詩》的票根，想必然是當年看那齣戲時帶着書上戲院，隨手夾在裏面，票根顯示日期為 2004 年 9 月 4 日 ── 影藝戲院的票根。

2004 年 9 月 4 日，我孤伶伶一個人往灣仔影藝戲院，在下午 2 時 45 分，佔着 H1 院的 E8 座位在看《花與愛麗詩》……。當時是怎樣的心情？當天是什麼樣的天氣？當天下午吃了什麼作午餐？全都想不起來，甚至連那齣戲的畫面、主角的面容與聲線，以至故事大綱，都已印象全失。八十八個月前的事，回想起來恍如隔世。

《挪威的森林》說的是主角渡邊徹三十七歲時坐飛機，機上播出 The Beatles 的 Norwegian Wood，因而憶起十八年前許許多多的往事。Norwegian Wood 是一個時代的象徵 ── 上世紀六十年代末，主角仍是青年的時候，正值是這首歌流行的年代。村上春樹於 1987 年寫成《挪威的森林》，將時間回卷十八載，就是 1969 年，恰好與書中主角回憶中的那個時代吻合。渡邊徹年青時的時代背境，亦即現實世界中村上春樹年青時的時代背境。

《挪威的森林》日文原著書名為《ノルウェイの森》，相信沒有人會對《挪威的森林》這個中文譯本的書名有異議，無論是台灣的賴明珠﹝繁體字版﹞、國內的林少華﹝簡體字版﹞，以至香港的葉蕙，都將書名譯為「挪威的森林」；而英文譯本不論是 Alfred Birnbaum 或 Jay Rubin 的版本，書名都是 "Norwegian Wood" 。在書中，Norwegian Wood 這首歌就等同於一個錨，抓着時間洪流中的一點，讓故事像漣漪般蕩漾開來。故此，將英文版的書名取為 "Norwegian Wood" 是理所當然的，因為 "Norwegian Wood" 原本就是一首英文歌的歌名，是英文，無需翻譯，亦沒有改動的餘地。可是偏偏有人硬將中文版的書名「挪威的森林」直譯為英文 "Norwegian Forest"，可謂牛頭對不上馬嘴。原本象徵著一個時代的歌名變成了北歐的森林，令人對青蔥歲月追憶不再，卻聯想起森林面積減少以致對全球暖化的憂慮。「世界」頓然失了真，亦顯得暗淡無光，原本想到那邊唞唞氣的都只有望門輕嘆。

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一年多前，《挪威的森林》被搬上螢幕，當時沒有看，最近才看 VCD，看過之後心情相當鬱悶。同一個故事，看書與看戲的感覺截然不同。也許是因為書中很多細節，單獨看起來無關痛癢，可有可無；但正正就是這些細節，一點一滴地將書中的人物的性格特質滲透出來。電影較為受制於片長，必然要對這些細節有所取捨，人物的性格便褪色了，更何況主角渡邊性格內歛，縱然心有千千結，亦沒有向身邊的朋友傾訴直子的事，朋友開口探問，他只謂事情太複雜而別過。唯主角在書中以第一人稱，讀者才能如懂讀心術般一窺他的內心世界。可是，書中的「我」在戲中變成了「他」，觀眾成了局外人。看着滿懷心事、不多說話的他，我直覺自已在看紀錄片 ── 一齣描述抑鬱症患者的紀錄片。

﹝待續﹞

別了，過去

我曾經病態地喜歡去圖書館，差不多每個星期六都去，那段日子足足持續了八年之久。

常留連於港大圖書館的 "special collection"，那兒專門擺放本地出版及以本地為提材的讀物，種類多不勝數，小說、散文集、畫冊應有盡有，很多都是罕見的絕版貨，連教科書都有，舊雜誌、地圖、上市公司年報、政府刊物、電話薄亦一應俱全，遠至數十甚至過百年前的出版亦有不少；但都不容外借。

遊走於書架之間，像在超市買東西一樣，目光隨意地往書架上掃，瞄到書脊上的書名，感到有趣的，便將書拉出來，就地站着隨意地翻，或是找個位子坐上大半天，一頁一頁地讀過不停，看得無味便找另一本來讀，倦了便伏在桌上打睡片刻，餓了便吃麵包夾朱古力，要知圖書館內是不讓人吃東西的，偷偷摸摸地吃，但總會小心翼翼以免弄污地方。

很多年沒有去了，前陣子突然心血來潮想去一趟，磨了好些日子，昨天終於去了，又是星期六。圖書館內景物依舊，我亦重操昔日的舉動，卻提不起絲毫看書的興緻，感受不回那些年的自得其樂，自覺有些無聊。我已不再是以前的我，究竟我是徹底地放下了，還是徹底地失去了呢？

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離開圖書館，在校園閒逛了一會，沒碰到一張熟悉的臉。來到黃克競平台，才知這兒改得翻天覆地，露天平台成了工地，看似是在進行加建，昔日大字報舖滿地的有蓋廣場竟不知於何時成了 canteen 。

畢業了十多年，這次回來，我第一次覺得自己是個陌生人。


黃克競的露天平台成了工地，國殤之柱都遷往一傍

跑，是為了平靜心境，感受自由

我每星期都要跑過步才覺心足，固執地沿那條過去廿多年來跑過上千次的路來回跑一趟，那怕是炎炎夏日的下午，烈日當空，溽暑蒸人；那怕落得氣喘如牛，大汗淋漓，雙腿發麻至提不起來。縱然累到再跑不動，仍要一步一步往前行。


從港島東的山腳起步，4.5 公里的路，由海拔 50 公尺爬昇至 200 公尺，去到跑馬地的半山，那分隔港島南北的分水嶺上。

我呆站在那裏，靜聽自己的呼吸和心跳，迎著山腳吹上來拂臉的風，對鬧市傳來的噪音充耳不聞 ── 5 分鐘，極度淡然的 5 分鍾 ── 讓時間安然地從身傍流逝。

疲乏的身軀，潔淨的靈魂，踏著沉實的腳步，一步一步沿路折返。光漸變昏黃，影子愈拉愈長。遠的、近的，目下都是眼熟的景物，就連路面的傾斜度與硬度，都和從前別無二致，感覺卻又不盡相同。

腿在動，心在跳，腦是在休眠狀態。跑，是為了平靜心境，感受自由。

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今晨到樓下的茶餐廳吃早餐，手捧村上春樹的《當我談跑步時，我談些什麼》，剛巧瞄到這一節：

「我跑步，只是跑著。原則上是在空白中跑步。也許是為了獲得空白而跑步。即便在這樣的空白當中，也有片時片刻的思緒潛入。這是理所當然的，人的心靈中不可能存在真正的空白。人類的精神還沒有強大到足以坐擁真空的程度，即使有，也不是一以貫之的。話雖如此，潛入奔跑著的我精神內部的這些思緒，或說念頭，無非空白的從屬物。它們不是內容，只是以空白為基軸，漸起漸漲的思緒。

跑步時浮上腦際的思緒，很像天際的雲朵，形狀各異，大小不同。它們飄然而來，又飄然而去，然而天空猶自是天空，一成不變。雲朵不過是匆匆過客，它穿過天空，來了去了。唯有天空留存下來。所謂天空，是既在又不在的東西，即是實體又不是實體，對於天空這種廣漠容器般的存在狀態，我們唯有照單收下，全盤接受。」

── 摘錄自《當我談跑步時，我談些什麼》村上春樹﹝施小煒譯﹞

The Poverty of Utilitarianism

A series of lectures delivered by Michael Sandel, a Professor of Government at Harvard University, is available on-line at:
http://www.justiceharvard.org/

If you have recently visited bookstores, you might have noticed a book entitled "Justice: What's the right thing to do?" showcased at the very eye-catching corner. That book, also authored by Michael Sandel, covers the same topics in his lectures.

I would recommend disciples of utilitarianism and those who claim themselves "logical" to spend ten minutes or so watching the beginning of Episode 02. Certainly, there are more intuitive concepts and knowledges to explore. It is really thought-provoking!

If you believe in universal human rights, you are probably not a utilitarian.

The above words were excepted from "Justice: What's the right thing to do?" by Michael Sandel.

I just think that people in this world have been overly doctrinated by naive ideas of economics and scientific management. The system sucks as people who are most deeply poisoned are honored as "well educated" and "smart", and are allowed to climb to the uppermost class of societies, awarded with wealth and authority. Injustice and inequality are results of their dogmatic narrow-mindedness and greed.

Listed below are a few meaningful excepts from "Justice" which introduce the principles of morality of Immanuel Kant:

The utilitarian's happiness principle contributes nothing whatever toward establishing morality... Basing morality on interests and preferences destroys its dignity... When we act autonomously, according to a law we give ourselves, we do something for its own sake, as an end in itself. We cease to be instruments of purposes given outside us. This capacity to act autonomously is what gives human life its special dignity. It marks out the difference between persons and things... [R]especting human dignity means treating persons as ends in themselves. This is why it is wrong to use people for the sake of the general welfare, as utilitarianism does.

We, human beings, have dignity and are worthy of respect! To some people, this merely sounds like a political slogan; to some other people, it echoes as savior's voice.

不容質疑的信仰

科學就是一堆可以被証明是對或者是錯的命題﹝ statement ﹞嗎？

大學時代與一名同窗好友討論過這個問題：「何謂科學？」 ── 最後得到一個雙方都感到滿意的答案：「科學就是一堆可以被証明是對或者是錯的命題，而証明可以是基於邏輯，亦可以是透過經歷。」﹝也許前者就是理論，後者就是實驗吧！﹞

十多年來我都沒有質疑過這個定義的真確性，因為我根本沒有認真地思考。如今一想，上述「定義」的確是個非對即錯的命題；問題是：這個命題可以被証明嗎？如果可以，我又想不出方法來；若然不可以，那我只能慨嘆一句：「科學」真喺唔科學！

兩星期前簡略地讀過 Karl Popper 的名著 The Logic of Scientific Discovery 。何謂科學？ Popper 是這樣說的：

"[N]o matter how many instances of white swans we may have observed, this does not justify the conclusion that all swans are white."

"[E]xperience[...]can in the first place be only a singular statement and not a universal one. [...]Thus to ask whether there are natural laws known to be true appears to be only another way of asking whether inductive inferences are logically justified."

"[P]rinciple of induction must be a synthetic statement[...It] must be a universal statement. [...]To justify it, we should have to employ inductive inferences; and to justify these we should have to assume an inductive principle of a higher order[...T]he attempt to base the principle of induction on experience breaks down, since it must lead to an infinite regress."

"[T]here is no such thing as a logical method of having new ideas[...E]very discovery contains 'an irrational element', or 'a creative intuition'[...]"

"[I]nference to theories, from singular statement which are verified by 'experience'[...]is logically inadmissible. Theories are, therefore, never empirically verifiable[...N]ot the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation."

"Science is not a system of certain, or well-established, statements; nor is it a system which steadily advances towards a state of finality[...] We do not know: we can only guess. And our guesses are guided by the unscientific, the metaphysical[...]faith in laws, in regularities which we can uncover - discover."

在這位哲學大師眼中，科學並非限於邏輯，因為世人只可憑經歷得出單稱命題﹝ singular statement ﹞，而自然定律皆是全稱命題﹝ universal statement ﹞。全稱命題只可從單稱命題憑邏輯歸納出來，而歸納原理﹝ Principle of Induction ﹞本身須是全稱的，否則歸納出來的命題就不可能是全稱的；但既然世人的經歷都是單稱的，全稱的歸納原理亦只可能是個無從證實的假說。換言之，世上存在自然定律，即所謂「萬物皆有序」只是信念﹝ belief ﹞。

科學講求實證，但既然經歷是單稱的，全稱的自然定律就不可能以經歷來確定﹝ verify ﹞ ── 縱使見過的一千隻天鵝都是白色，豈知第一千零一隻不會是白色而是黑色？只要世上有一隻黑天鵝，「世上只有白天鵝」這「定律」便遭否定﹝ falsify ﹞。因此，科學應以否證﹝ falsification ﹞為依歸。無論如何，以經歷為鑑，就是相信因果關係﹝ causality ﹞ ── 「事出必有因」：事件為果，必存在某自然定律為其因。

「萬物皆有序」與「事出必有因」都只能信，不可能不信。若說自然定律不存在，在科學的框架中，我們便應嘗試否定這個假說，那正正是在尋找自然定律，自打嘴巴。因果關係就更玄妙，你懷疑，做實驗意圖否定它，得出的是因還是果呢？除了疑惑，你還可以怎樣？

所謂科學，骨子裡只是一份信念 ── 深信「萬物皆有序」、篤定「事出必有因」；基於這份信念作出假設，並嘗試以實證方法于以否定……。

說到底，科學是不容質疑的信仰。

情迷黑天鵝

勿以為談的是 Natalie Portman 飾演芭蕾舞蹈員的得獎電影《黑天鵝》；要說的其實是 Nassim Nicholas Taleb 的名著《黑天鵝》﹝The BLACK SWAN: The Impact of the Highly Improbable﹞。

很多人都讀過《黑天鵝》這本書，亦知道所謂的「黑天鵝」指什麼；但有幾多人留意到 Taleb 這本享負盛名之作，是向 Benoît Mandelbrot 致意的呢？書首乾乾淨淨的一頁白，印著：

To Benoît Mandelbrot,
a Greek among Romans

諗過理科的都不會對這個名字感到陌生吧！ Benoît Mandelbrot ，世人尊稱他為分形幾何學之父， 對於其生平事跡，維基百科講得十分詳盡，在此不贅。唯一想指出的，是他發現金融市場中的價格變化並不依循常態分佈﹝ normal distribution ﹞，而是遵從 Lévy stable distributions ，價格的上落亦非隨機﹝ random ﹞，而是 fractional Brownian motion in multi-fractal time 。

可是他的理論備受冷落，眼見金融學日益興盛，但內容盡是建基於不盡不實的假設之上，架牀疊屋地用數學推導出來的「垃圾」，而推出這堆「垃圾」的學者居然一個又一個地獲頒諾貝爾經濟學獎，他的心情可想而知。

在 2007 年《黑天鵝》初版推出之際，金融海嘯尚未發生， Taleb 在書中已指出世人普遍以一堆猶如「垃圾」的金融理論來衡量風險，遲早出事。這本書風靡全球，除因為其涉及面既廣且深﹝不單限於經濟與金融，而及至哲學﹞，且有先見之明之外，作者對象牙塔學者不留情面的批評，言詞尖酸之程度，可謂一絕：

'The Nobel Committee could have tested the Sharpe and Markowitz models - they work like quack remedies sold on the Internet - but nobody in Stockholm seems to have thought of it. Nor did the committee come to us practitioners to ask us our opinions; instead it relied on an academic vetting process that, in some disciplines, can be corrupt all the way to the marrow. After that award I made a prediction: "In a world in which these two get the Nobel, anything can happen. Anyone can become president."'
    ── 節錄自《黑天鵝》第 17 章

《黑天鵝》這本書的意義在於警世，亦替 Benoît Mandelbrot 抱了個不平：

'In sum, four decades ago, Mandelbrot gave pearls to economists and résumé-building philistines, which they rejected because the ideas were too good for them. It was, as the saying goes, margaritas ante porcos, pearls before swine.'
    ── 節錄自《黑天鵝》第 16 章

可知古時偉大的數學家﹝尤指幾何學家﹞皆出於希臘；而羅馬人基本上是輕蔑數學的，縱然算術及概率理論﹝用於賭博？﹞是源自羅馬。Taleb 稱 Benoît Mandelbrot 為 'a Greek among Romans' 實在可圈可點。

'Clouds are not spheres, mountains are not cones, coastlines are not circles, and bark is not smooth, nor does lightning travel in a straight line.'     ── Benoît Mandelbrot (1924-2010)

參考資料：
。The BLACK SWAN: The Impact of the highly improbable, Nassim Nicholas Taleb
。The (Mis)behavior of markets: A fractal view of risk, ruin & reward, Benoît Mandelbrot & Richard Hudson
。How Fractals Can Explain What's Wrong with Wall Street, Benoît Mandelbrot, Feb 1999, Scientific American
。The Drunkard's Walk: How randomness rules our lives, Leonard Mlodinow

埋首於書堆中的駝鳥 ── 2011 篇

• 《玩回底片機》藤田一咲﹝許明煌 譯﹞
• 《愛上老相機》老查
• 《投資導航﹝上卷﹞── 觀勢指標篇》信報研究部
• 《投資導航﹝下卷﹞── 選股實戰篇》信報研究部
• 《鑒股知金 ── 環球經勢啟示錄》羅耕
• 《1Q84 〈10月-12月〉》村上春树﹝施小炜 译﹞
• 《勢事循環 ── 市場周期與投資智慧》羅家聰
• 《時移勢易 ── 迎戰多底衰退大時代》羅家聰
• 《鍍金中國 ── 大國雄起的虛與實》許知遠
• 《玩味經典相機》藤田一咲﹝許郁文 譯﹞
• 《翹首振翅 ── 香港飛機師手記 I 》
• 《翹首振翅 ── 香港飛機師手記 II 》
• 《雲圖鑑》田中達也﹝黃郁婷 譯﹞
• 《香港四代人》呂大樂
• 《停車暫借問》鍾曉陽
• 《哲人哲語》陳永明
• 《挪威的森林》村上春樹﹝林少華 譯﹞﹝重閱﹞
• 《挪威沒有森林》福原愛姬﹝若彤 譯﹞﹝重閱﹞
• The Oil Factor: Protect Yourself and Profit from the Coming Energy Crisis, Stephen Leeb & Donna Leeb
• The Logic of Scientific Discovery, Karl Popper
• Justice: What's the Right Thing to Do?, Michael Sandel
• When Corporations Rule the World, David Korten
• The Met Office Pocket Cloud Book, Richard Hamblyn
• The Cloud Collector's Handbook, Gavin Pretor-Pinney
• The Golden Ratio, Mario Livio
• Nature's Patterns: A Tapestry in Three Parts: Flow, Philip Ball
• Nature's Patterns: A Tapestry in Three Parts: Branches, Philip Ball
• Nature's Patterns: A Tapestry in Three Parts: Shapes, Philip Ball
• Political Philosophy: A Very Short Introduction, David Miller
• The Paradox of Choice: Why More is Less, Barry Schwartz
• Neoliberalism: A Very Short Introduction, Manfred Steger & Ravi Roy