Multiple Realizability 多重具現性

The multiple realizability thesis about the mental is that a given psychological kind (like pain) can be realized by many distinct physical kinds: brain states in the case of earthly mammals, electronic states in the case of properly programmed digital computers, green slime states in the case of extraterrestrials, and so on.
多重具現性，指的是心理狀態（例如疼痛）可以由不同的物理性質來說明。例如大腦神經狀態，不同的路生哺乳類、由設計程式來計算的電腦、長得像綠色黏漿的外星人，只要有腦神經狀態，不論他是甚麼東西，都能由多重具現性來說明。
Correctly characterizing the realization relation remains a contentious(debatable) matter in analytic metaphysics (Gillett 2003, Polger 2004). But whatever the correct account turns out to be, the multiple realizability thesis about the mental is that a given psychological kind (like pain) can stand in that relationship to many distinct physical kinds.
In a pair of examples illustrating multiple realizability in special sciences (economics and psychology), Jerry Fodor (1974) implicitly distinguished between two types of the relation.
Call the first type, illustrated in the examples provided at the end of the previous paragraph, multiple realizability "over physical structure-types": creatures with distinct physical structures realizing their psychological states can nevertheless entertain the same psychological states. A more radical type of multiple realizability would obtain if a token physical (e.g., nervous) system can realize a single mental kind via distinct physical states of that same system at different times.
Call this second sense multiple realizability "in a token system over times." (These terms are from John Bickle 1998, Chapter 4.) This second sense is more radical because there could be a disjunction of physical states realizing each mental kind for every existing cognizer. The importance of the more radical type is discussed further.

In a series of papers published throughout the 1960s, Hilary Putnam into the introduced multiple realizability into the philosophy of mind. Against the "brain state theorists," who held that every mental kind is identical to some as-yet-undiscovered neural kind, Putnam (1967) notes the wide variety of terrestrial creatures seemingly capable of experiencing pain. Humans, other primates, other mammals, birds, reptiles, amphibians, and even mollusks (e.g., octopi) seem reasonable candidates. But then for the “brain state theory” to be true, there must be some physical-chemical kind common to this wide variety of pain-bearing species, and correlated exactly with each occurrence of the mental kind. (This is a necessary condition of the hypothesized type-identity.) But comparative neuroanatomy and physiology, facts about convergent evolution, and the corticalization（皮質層化） of function (especially sensory function) as cortical mass increases across species all speak against this requirement.
一九六零年代，帕南展開在心靈哲學當中對多重具現性的探究。他認為大腦狀態的理論所主張的，心理狀態與某些還不很清楚地被我們知道的類神經狀態是可等同的，像陸地生物和人類的疼痛可藉由大腦狀態說明。如果大腦狀態的理論是對的，物理和化學的那些性質就能用來說明疼痛這種心理狀態的發生，但是，相對的，神經解剖學和生理學研究的進路是研究大腦皮質層功能的學科，他們對於這種等同的主張還是抱持著質疑的立場。
In addition, early mind-brain identity theorists insisted that these identities, while contingent, hold by virtue of natural (scientific) law. But then any physically possible cognizer (e.g., pain-bearer) must also be capable of possessing that physical-chemical kind. Here the well-known philosophers' fantasies enter the discussion. Silicon-based androids（矽基人造人）, artificially intelligent electronic robots, and Martians with green slime pulsating（外星人） within their skulls all seem to be possible pain realizers. But they lack “brain states” comparable to ours at any level of physical description. Further still, these mind-brain identity theories were supposed to be completely general. Every mental kind was held to be identical to some neural kind. So the critic needs to find only one mental kind, shared across species yet realized differently at the physical-chemical level. Putnam acknowledges that the early identity theories were empirical hypotheses. But one of their consequences was "certainly ambitious" and very probably false.
而且，心腦同一論與等同理論的主張還是仰賴對於自然律的偶然性。（“自然律“幾乎是科學哲學研究中的濫觴。）而這些自然律的偶然性僅只是科學實驗過程當中可能的而已。無論是人造人還是人工智慧的機器人，或者是外星人腦殻的大腦狀態，它們的疼痛與我們人類的疼痛也只是具現上可能的（realizational possible)而已。具現上可能並不是必然的關係。也就是說 ，無論非人類的東西的疼痛與人累的疼痛有多像，都只是物理性質上相容罷了。心腦同一論的主張基本上是一個太強的主張，任何心裡狀態都能與大腦狀態等同，是必然的嗎？如果這是一個必然的關係，任何一個心理狀態都不能被除了它以外的物理性質所具現。帕南認為，早期的等同理論只能是經驗上的實驗的假設，最後還是必須面對“確定性的歧義“的挑戰，但是這個理論（心腦同一論）的主張很有可能最後還是錯誤的。
Stated in canonical form（語法或結構的最基本形式）, Putnam's original multiple realizability argument draws an anti-identity theory conclusion from two premises:

1. (the multiple realizability thesis) All mental kinds are multiply realizable by distinct physical kinds.
2. If a given mental kind is multiply realizable by distinct physical kinds, then it cannot be identical to any specific physical kind.
3. (the anti-identity thesis conclusion) No mental kind is identical to any specific physical kind.

1.所有的心理狀態都可以由物理性質所具現。（根據心理狀態與物理性質之間的多重具現關係）

2.如果心理狀態是可以由各種不同的物理性質所多重具現的，那麼單一個心理狀態就不可能和其他類的物理性質所等同。（根據1, 存在量化號的否定用QN展開為全稱量化後個體的否定）

3.（反等同論的結論）沒有任何心理狀態是與任何物理性質等同的。（根據1, 2，MP )

In this simple form, this is a deductively valid argument.
Fodor (1974) extended Putnam's initial argument by arguing that reductionism imposes too strong a constraint on acceptable theories in special sciences like psychology. According to Fodor, reductionism is the conjunction of "token physicalism" with the claim that there are natural kind predicates in an ideally completed physics corresponding to each natural kind term in any ideally completed special science. He characterized "token physicalism" in turn as the claim that all events that science talks about are physical events—a weaker thesis than reductionism or type-type physicalism. Consider the following string of numerals:

1 1 2.

This string contains two types of numerals (1 and 2), but three tokens of the two types (two tokens of the numeral type 1 and one token of the numeral type 2). Mental states admit of a similar ambiguity. When you and I both entertain the belief that Fodor advocates a Language of Thought, one type of mental state is entertained, but two tokens of that type (your belief state and my belief state). Type-type physicalism insists that types of mental states are identical to types of physical states; this view runs afoul of multiple realizability. But token physicalism only insists that each token occurrence of each type of mental state is identical to some token occurrence of a physical state type—not necessarily an occurrence of a token of the same physical state type on each occasion.
Fodor根據帕南論證的基本想法，主張化約論的做法就像心理學一樣，太過於強調科學實驗的相容性，但是忽略心理狀態與科學實驗語彙的歧義性。如果你接受Fodor的思維語言假設（language of thought hypothesis)，單一心理狀態類型可以有兩種個例，比如我和妹妹都相信今天母親生日，我和妹妹都有“相信“這個心理狀態，但是我和妹妹的心理狀態都只是“相信“這個心裡狀態的個例。類型物理論認為心理狀態的類型與物理狀態類型是等同的，這個觀點造成多重可具現性的淒慘下場。但個例物理論只認為心理狀態顯示了那個類型的心理狀態，和心理狀態並不是等同的。
Fodor gave reductionists the best-developed theory of reduction at the time: Ernest Nagel's (1961) "derivability" account of intertheoretic reduction. Nagel's account "connects" disparate(different) elements of the reduced and reducing theories' vocabularies via "bridge laws" (not Nagel's term!) and claims a reduction when the laws of the reduced theory are derived from the laws of the reducing and the bridge laws. According to Fodor (1974), if reductionism is to establish physicalism, these cross-theoretic bridge laws must assert (contingent) identities of reduced and reducing kinds. But given multiple realizability, the only way this can obtain is if the physical science constituent of a psychophysical bridge law is a disjunction of all the terms denoting possible physical realizations of the mental kind. Given the extent and variety of actual (not to say possible) physical realizations, it is overwhelmingly likely that the disjunctive component will not be a kind-predicate of any specific physical science. It is also overwhelmingly likely that the disjunctive component will not appear in any genuine law of a specific physical science. Multiple realizability thus demonstrates that the additional requirement of reductionism (beyond token physicalism) is empirically untenable.
Fodor的化約主張正是Nagel跨理論化約之意：可推導性。Nagel認為，“連結“、化約到物理性、化約理論的語彙通道：自然律之橋；也就是說，當我們進行化約時，理論所提供的化約線索是可以藉由化約的規律所推導進行的。Fodor認為，如果物理論的化約論是可行的，那麼跨理論的自然律之橋就顯示，藉著偶然上的等同關係，我們的化約工作可以進行：心理狀態化約到物理性。但，多重可具現性只能說，如果物理科學建構了心理學自然律，我們也只能說，心理狀態化約到物理的辭彙是物理上具現可能的。因為多重可具現性所主張的現實上物理性只是和我們的實驗語彙可相容，不代表它已經克服了物理科學實驗的必然連結性，甚至已經可以等同於我們的物理世界所呈的所有科學實驗結果。多重可具現性因此只抓住了化約論（除了個例物理論）所加上的經驗判斷，但是經驗判斷仍然令得我們存有困惑。

claims for the theory to reason causation

CTM rose to prominence as one of the most important theories of mind in the 1980s. This may in part have been due to the intuitive attention of the computer metaphor, which played upon the notion of a technology that was rapidly gaining public recognition and technological applications.

By this time, moreover, the computer had influenced the understanding of the mind through the influence some projects in the sciences of cognition and in artificial intelligence, where researchers sought to endow machines with human-level competences in reasoning, language, problem-solving and perception, though not always by replicating the mechanisms by which these are performed in humans.

In addition, CTM's advocates also claimed that it provided solutions to several important philosophical problems, and its plausibility in these areas was an important contributor to its rapid rise to popularity.

The most important philosophical benefit claimed for CTM was that it purported to show how reasoning could be a non-mysterious sort of causal process, and could nonetheless be sensitive to semantic relations between judgments. The background problem here was the received view that reasons are not causes. On the one hand, it is hard to see how a purely causal process could proceed on the basis of the semantic values of propositions.

To posit a mechanism that understood the meanings of mental symbols would in effect be to posit a little interpreter or homunculus inside the head, and then the same problems of coordinating reason and causation would recur for the homunculus, resulting in a regress of interpreters. On the other hand, it is hard to see how a process specified in purely causal terms could thereby count as a reasoning process, as calling something "reasoning" locates it with respect to norms and not merely to causes. ( That is , to call a process "rational" is not merely to describe its causal etiology, but to say that it meets, or at least is evaluable by, certain standards of reasoning, such as validity.)

CTM的理論在電腦技術發展起來之後，被我們的心靈理論所重視。大概是因為電腦這個科技背後所隱含的意義，包括了我們在直覺上運用心智與認知的技術的科技和能力所導致吧。時至今日，電腦科學已經廣泛被理解，認知科學家在研究人工智慧時，關注著電腦與人類操作語言、理性、解決問題與感覺的差異，雖然電腦做出的這類事情仍不及人類。

CTM在研究理性的議題上使得我們脫離那種虛而不實的理解。而且逐漸理解語意與判斷的關聯。這背後的問題是，理性的研究不等於因果關係的研究。也就是說，無法純粹由理解因果關係的運作來理解命題中最基本的語意值的運作。我們研究命題中的因果關係並無助益於我們去理解理性的運作，因為我們關注的是辭彙理解，而不是因果鏈。好比說，一個理性的決策過程與描繪一個病理的因果關係並無不同，但是，至少意義上可以這麼說，一個確定的理性模型就是一個確定的因果關係模型，例如有效性的模型。

fifty questions of philosophy - sorites paradox

Supposed that you have a full head of hair. That means that you probably have around 100,000 individual hair. Now pull one of them out. Does that make you bald? Of course not. As single hair doesn't make any difference. 99,999 hairs still make a full head of hair.

滿頭黑髮的你，會因為不小心拔了一根起來就成了禿頭嗎？當然不會。

Indeed, we would surely all agree that, if you are not bald, removing just one hair could never make you bald. And yet, if you pull out another hair, and another, and another... Eventually, if you carry on long enough, you will have none left and you will indubitably be bald. So you apparently move from a state of unquestionable non-baldness to a state of unquestionable baldness by taking a series of steps that can never on their own have that effect. So when did the change come about?

如果你很確定你不是禿頭，那麼拔掉一根頭髮當然不會使你變成禿頭。而如果，你拔了一根頭髮，又一根頭髮，又一根頭髮。。。直到你的頭髮都拔完為止，那麼你當然就成了一個禿頭。這個禿頭的推論，是典型的堆垛悖論形式。而我們能從這個推論形式得到些甚麼？

This is a version of a famous puzzle, usually attributed to the ancient Greek logician Eubulides of Miletus, know as the sorties paradox. 'Sorties' comes from the Greek word soros, meaning a 'heap', as the original formulation of the puzzle features a heap of sand. Expressed in terms of addition rather than subtraction, the argument looks like this:

1 grain of sand does not make a heap.

If 1 grain does not make a heap, then 2 grains do not.

If 2 grains do not make a heap, then 3 grains do not.

[and so on until . . ]

If 99,999 grains do not make a heap, then 100,000 grains do not.

So 100,000 grains of sand do not make a heap.

But everybody would surely baulk at this conclusion. So what can have gone wrong?

從一顆穀粒不能構成一堆，我們會推論出二顆穀粒也不構成一堆，。。。進而推論得到一萬顆穀粒也不構成一堆。但是，很顯然我們會同意一萬顆穀粒是一堆，那麼是我們推論時出了甚麼錯嗎？

Problem of vagueness

Faced with an unpalatable conclusion of this kind, it is necessary to track back over the argument by which it has been reached. There must be something wrong with the premises on which the argument is based or some error in the reasoning. In fact, in spite of its great antiquity, there is still no clear consensus on how best to tackle this paradox, and various approaches have been taken.

我們回去檢查這個悖論的推論形式與前提，似乎也對於我們釐清這個悖論沒有多大用處，反而是企圖削弱這個悖論的理論不停地被研究著。

One way out of the paradox is to insist, as some have done, that there is a point at which adding a grain of sand makes a difference; there is a precise number of grains of sand that marks the boundary between a heap and a non-heap. If there is such a boundary, clearly we do not know where it is, and any proposed dividing line sounds hopelessly arbitrary: do 1001 grains, say, make a heap, but not 999? This really is a bog slap in the face for common sense and our shared intuitions.

倒有一件事和研究這個悖論相關的，那就是：加上一顆穀粒和減少一顆穀粒，比如10000和9999之間的差別，造成它是一堆或者不是一堆。而我們是不是真的能夠畫出這般清楚的界線呢? 假如這個界線是很清楚的，那我們現在仍不知道這界線在哪裡，或者我們任意地畫出來罷了。

More promising is to take a closer look at a major assumption underlying the argument: the idea that the process of construction by which a non-heap becomes a heap can be fully and reductively analyzed into a series of discrete grain additions. Clearly there are a number of such discrete steps, but equally clearly it seems that these steps are not fully constitutive of the overall process of heap-building.

最重要的部分則是在於這個論證的前提：減少不是一堆的那堆的穀粒數量是一個離散的(不連續)增加數值方式。很顯然的，這個模糊理論的方式是，藉由一步一步的方式建構出"一堆"的意思。

This faulty analysis fails to recognize that the transition from non-heap to heap is a continuum, and hence that there is no precise point at which the change can be said to occur. This in turn tells us something about the whole class of terms to which the sorites paradox can be applied: not only heap and bald, but also tall, big, rich, fat and countless. All of these terms are essentially vague, with no clear dividing line separating them from their opposites - short, small, poor, thin, ect.

因為建構一堆與不是一堆是一個連續的過程，因此我們無法劃出一個很明顯的點來區別一堆與不是一堆的改變。

One important consequence of this is that there are always borderline cases where the terms do not clearly apply. So, for instance, while there may be some people who are clearly bald and others who are clearly not, there are many in between who might, according to context and circumstances, be designated as one or the other. This inherent vagueness means that it is not always appropriate to say of a sentence such as 'X is bald' that is (unequivocally) true or false; rather, there are degrees of truth. This at once creates a tension between these vague terms that occur in natural language and classical logic, which is bivalence (meaning that every proposition must be either true or false).

我們總是無法從這種邊界事例當中找出清楚劃清界限的方式。不過，我們還是可以在日常生活或是實際的例子找出哪些人是禿頭，而且很明確；哪些人不是禿頭。而模糊性的意思就是，我們在使用「X是禿頭」這類句子的時候，「是禿頭」是程度上的真，而非全部的真。一旦我們僅止用二值原則來處理這類語詞時，模糊性的問題就會出現。

The concept of vagueness suggests that classical logic must be overhauled if it is to fully capture the nuances of natural language. For this reason there has been move towards the development of fuzzy and other multivalued logics.

研究這論證的細微末節，使我們發現與研究除了二值以外的其他邏輯。

fifty questions of philosophy - The difference principle

第一段

Main idea : 'just societies are more stable and longer-lasting than unjust ones'

一個正義的社會比一個不正義的社會更穩定持久。

Support idea: 'The members of a society must believe that it is, by and large, fair if they are to abide by the rules that hold it together and to maintain its institutions.'

假設這個社會的法律與制度是公平的，那麼這個社會的成員，無論如何，遵守這個社會的法律和制度，可保障這個社會不至於成為一個零散的部落，也保障這個社會的成員的安全與生活。

所謂的stable society，指的是政治學上追求的理想社會，那是一個沒有戰爭、沒有革命、沒有鬥爭的安定社會。

Relational sentence: 'So how should the burdens and benefits of a society be distributed amongst its members in such a way as to make it just?'

延伸假設的問題是：一個公平的社會法律制度要如何建立？這個問題導出羅爾斯的main point:如何公平地分配權利與義務？

第二段

Main idea: 'only truly fair distribution of society's good is one that is equal across all its members. '

公平地分配社會上的權利與財富就會是對於每個社會成員來說平等的分配。

Support idea: 'Equality can mean different things,...

equality of outcome, such that everyone has an equal share of the wealth and benefits that society has to offer and everyone has to shoulder an equal share of the burdens'

第一種平等的分配方式是齊頭式的平等，無論我們在哪一個起跑點上，最後的結果是每個人都獲得均等的財富與權利。而每個人也都負擔相同的責任與義務。

'So perhaps the important thing is equality of opportunity, such that everyone in society has the same opportunities to prosper, even if some people make more of them than others and accrue more of the benefits in doing so.'

第二種平等的分配方式是機會的平等，無論我們起跑後有什麼可能的發展情形，我們都保障每一個社會成員都有能力和別人一起起跑。即使有些人是天生條件就比較好，能夠累積比別人更多的財富與權利。

Relational sentence: 'But some people's shoulders are broader and stronger than others, and society as a whole may profit from the great efforts that some of its members are able to make. If people are willing to make more efforts, it is not reasonable for them to take a larger share of the benefits?

有些人天生的能力比其他人更好，如果這些人願意付出和他們能力相等的責任與義務，難道我們不應該給他們比別人更多的權利與財富嗎？

第三段

Main idea: 'At the core of his theory lies the so-called 'difference principle', according to which inequalities in society are justified only if they result in its worst off members being better off than they would otherwise have been.'

根據羅爾斯的差異原則，一個正義的社會，指的是那些少數的、弱勢的人有相對的保障 。

第四段

Behind the veil of ignorance 無知之幕

Main sentence: 'We asked to imagine ourselves in what he calls the 'original position', in which all personal interests and allegiances are forgotten: 'no one knows....' Though we might seek to further our own interests, we do not know where our interests lie, so special pleading is ruled out.'

這是羅爾斯的一個思想實驗：現在，我們想像自己進入這個社會之前，我們完全不知道這個社會將是甚麼樣子的社會，也不知道我們自己有什麼能力，不知道自己在這個社會將會是甚麼樣子；因此，我們無法預期自己能有什麼好處，也無法設計出有利於自己的社會制度與法律。

第五段

Main sentence: 'Impartiality, then, in a paradox that is apparent only, is the rational and inevitable choice of self-interested agents in the original position.'

中立的弔詭之處在於，除非我們在原初位置上就不知道自己在正義的社會，否則我們將會做出有利於自己的審慎決定，而那樣的社會並不符合正義與公平。

Support sentence: '... if they were contracted into from behind this imaginary 'veil of ignorance.' Moreover, whatever would be agreed to in such circumstances is the only thing that could be agreed to by individuals acting rationally and prudentially.'

如果我們在無知之幕下定立社會契約，無論即將面對哪一種情況，這樣的社會對個人而言都會符合正義與公平。

第六段

Main sentence: ' the idea that inequalities are acceptable only if they benefit the worst-off - is that under any other circumstances inequalities are unacceptable.'

差異原則只有在保障弱勢的人的情況下，才能被接受。

Support sentence: 'economic arrangements that greatly enhance the position of the better-off but leave the standing of the worst-off uncharged would not count as just.'

經濟學的分配方式只是保障那些比一般更優異條件的人，卻沒有保障那些弱勢的人，這種分配方式不符合正義。

Conclusion: 'In sum, inequality is just only if everyone profits by it; otherwise equality should prevail.'

因此，公平的正義是在所有人都能因此獲得相等的收益，否則公平就只是壓迫少數人的手段罷了。

Scope of CTM

The most obvious domain for CTM is that of occurrent propositional attitude state - that is, states that occur at some specific moment in a person's mental life, and the sort of content that might be expressed by a propositional phrase.

CTM(Computation theory of mind)最明顯的就範圍包含對命題的研究，而命題態度的事件是指某人在特定狀況下的心理歷程。

Here we perhaps have the most plausible case of mental states that might be grounded in something like token mental representations.

心理狀態包含很多東西，就例如像個例心理表徵物。

Within this class of occurrent states, we may additionally distinguish between the kinds of states that occur in explicit, conscious judgments and mental states that are not conscious because they take place at a "level of processing" that is too low to be brought to conscious awareness.

那些東西發生在某些時刻裡，我們可能會因此將它們和出現在特殊時刻的心理狀態區分開。意識的判斷和心理狀態是完全不同的，他們在不同層次裡運作不同的工作，因而我們可以區別哪些是較低層次的意識思考。

However, advocates of CTM often speak of it more generally as an account of beliefs and desires which are then cased out in dispositional rather than occurrent terms. Such states are arguably more problematic for CTM than occurrent states, as there are many things one might be thought to "believe" or "desire" in the dispositional senses of those terms, but which could not plausibly be supposed to be explicitly represented in the form of a symbol token.

信念以及欲望，比較像屬於傾向而不只是表面上的詞而已。對於這類研究，CTM還是被受爭議和討論的理論，由其像是研究"相信"和"想要"這類有傾向意思的詞。不過這並不能假設說，我們用這類詞的個例表徵了那些特定心理狀態。Somehow我們確實在某些時刻會有傾向去相信和想要某些對象，卻不能反向推論。

An additional issue regarding the intended scope of the theory is that of how comprehensive an account of mental states and processes it is intended to be.

Advocates of CTM and critics alike have often assumed that CTM makes claims to be a quite general account of reasoning. This is complicated, however, by Fodor's [1984] distinction between "modular' and "global" mental processes, and his judgment (in Fodor [2000]) that it is only the former that are likely to be computational in the classic sense.

CTM企圖做出普遍和可以模組化的心理歷程。

While this view has struck some readers as surprising, Fodor claims that, while advocating the truth of CTM since the 1970's, it "hadn't occurred to [him] that anyone could think that it's a very large part of the truth; still less that it's within miles of being the whole story about how the mind works."

到1970年為止，CTM都還不算是能夠說服那些解釋心理歷程的理論，因為它說明的還不夠多。

We may therefore refine questions about the truth of CTM to questions about its truth as a theory of particular kinds of mental processes.

fifty questions of philosophy - the golden rule

Golden rule對追求德善的哲學思考以及信仰來說，它的普遍運用性成為倫理系統重要的一環。好比互助與互惠，在經濟人類學的名詞：全球互惠原則，人們的交易行為，或者說等價的交換，運用著最形式化的golden rule。好比第三者中立地看待事件，他們強調的正是golden rule要求的普遍運用，目的在於帶來最具德善的人類行為。

但是，人類行為的可變化性無時無刻，golden rule的普遍化要求在不同的倫理系統當中會遭遇不同的困難，這些困難來自於變化無窮的人與人之間的關係；無論如何，律則不可能是一成不變。

Golden rule有一項精緻的成果，就是中立/理想的第三者。什麼意思？

理想的旁觀者，這個概念設想我們人類有一種天生、不須學習的能力，也就是我們可以運用知識這件事情；這件事情怎麼樣呢？這件事情是可能被現實世界的各種因素給扭曲，例如無知，它會使人傷害別人、例如朋友之間因為缺乏同情而產生裂隙。一個理想的旁觀者既不會因為自己的喜好而趨向某種行為，也不會因現實世界的各種因素蒙蔽他的判斷。

這種人擁有一搬人都有的：獲得知識的能力，但是他的訊息獲得經過一串道德情感上的測試，與某些人不同的地方在於他天生能夠用到德情操檢驗知識，一般上稱為良知良能。一個最好的上位者擁有天生的能力來運用聰明才智，他在國家機器操作體系之下依然運用良知良能檢驗自己的行為。

人的同情心、懼怕的心、恨某人、愛某人，對一個有良好判斷力的人來說，他的各種喜好都是根據良知良能的道德情操，以及合法的行為規範。

一旦我們決定某個行為的普遍性，毫無疑問來自於我們自己擁有多少良知良能，根據這些良知良能，我們做出行為，我們做出判斷。糟糕的人是那些因為無知，而導致傷害一些弱勢、孤單的人。即使，人的所知必然是有限，承認自己的有限性也不妨礙我們做出現實上最好的判斷。科學的眼光告訴我們，倫理律則就像科學律則，將最大公約數當作公理；這不意味最大利益是最大公約數；我們推論符合這個世界運行的倫理事實。

同情心，以及寬大的胸懷，幫助運用知識的良知可以推行到理想的行為。

Identity theory, a beginner guide

The identity theory gets its name because it identifies - claims an identity between - mental states and certain brain states. I say 'certain' brain state because whilst the identity theory claim that every mental is a brain state, it is not committed to the converse. In fact, it's certainly not the case that every brain state is a mental state. For example, in addition to billions of neurons, the human brain contains a large number of glial cells which play a supportive and protective role. It's unlikely that any mental state is identical with a state of one or more glial cells.

It's fair to say that the identity theory offers convincing explanations of three of the six features, and that it may turn out to be compatible with sophisticated attempts to explain two of the remaining features.

However, one of feature of mental state - consciousness - presents a serious challenge to the identity theory. In this section we will discuss those features of mental states which the identity theory, or a theory compatible with it, can explain.

1. Some mental states are caused by the world. Example: Bloggs's belief that there is a cup of coffee in front of him (mental state) is caused by there being a cup of coffee in front of him (state of the world).

If, as the identity theory claims, mental states are brain states, then the first feature amounts to the claim that some brain states (the ones held by the identity theory to be identical with certain mental states) are caused by states of the world. Research in neuroscience gives us grounds for thinking that this is true. For example, the causal impact of seeing a cup of coffee can be traced deep into the brain. Light from the cup stimulates the light-sensitive cells at the back of the eye (the brain), and information about the pattern of stimulation on the retina is carried into the brain by the optic nerve. (Intriguingly, the pattern of activation on the retina is reproduced many times in the visual centers of the brain.)

2. Some mental state cause actions. Example: Blogg's desire for another coffee (mental state) together with his belief that there is more coffee in the kitchen (mental state), caused him to go into the kitchen (action).

If the identity theory is to explain the second feature of mental states, it must be the case that certain brain states cause actions like going to the kitchen for a coffee. Research in neuroscience makes it overwhelmingly likely that this is the case. We have very good evidence that actions are caused by activity in a part of the brain called the motor cortex.

3. Some mental states cause other mental states. Example: Bloggs's belief that it's Friday (mental state) , together with his belief that Friday is payday (mental state), caused him to believe that it's payday (mental state).

If, as the identity theory insists, mental states are brain states, then the claim that some mental states cause other mental state is supported by the fact that some brain states cause other brain states. However, as we noted in the Introduction, there is something special about the way mental states interact with each other. Notice that my belief that it was Friday, together with my belief that Friday is payday, give me good reason to believe that it's payday. To put this point another way: the causal relations between mental states often respect the rational relations between them. However, it is controversial whether that account of the rationality of thought can be squared with the claim that mental states are brain states.

4. Some mental states are conscious. For the moment we can simply note that some mental states have a subjective 'feel' or 'quality'. Perhaps the easiest way to grasp the idea that some mental states have a subjective feel or quality is to contrast the mental life of a person with normal color vision with that of a person who is colorblind. When they stand together looking at a sunset, the visual experiences of the person with normal color vision are quite different from those of the colorblind person. The former's experiences have a feel or quality which the latter's lack.

5. Some mental states are about things in the world. That is, they represent the world as being a certain way. For example, Bloggs's belief that Mt Everest is 8,848 meters tall is about Mt Everest and represents Mt Everest as being 8,848 meters tall.

6. Some kinds of mental states are systematically correlated with certain kinds of brain states. According to the identity theory, mental states literally are brain states. Consequently, the identity theory smoothly explains the systematic correlation of mental states with brain states.

Aristotle-Ancient Ethical Theory

亞里斯多德的道德理論，像他的老師柏拉圖一樣，重視德性(virtue)的探究。循德性的人生與某人的幸福是一致的。在《尼各馬克倫理學》的第一卷，他首先探討了幸福是什麼，然而什麼是幸福? 在《尼各馬克倫理學》的第十卷，他說，幸福與我們靈魂的最好的那部分一致，而且在行為上一致。什麼意思呢? 換言之，當我們思考一個行為如何如何的時候，我們運用的是人的某種特殊的智慧，那就是我們靈魂最好的那部分所獲得的。

Somehow，我們決定一項行為，或者考量我們的行為，這與考量我們的幸福人生有關，最好的智慧處理人與人的相處方式與做為的時候，就是正在考量一項政治上的行為。為什麼呢? 因為，我們思考的對象是具體的享受，是具體的快樂，在政治的作為上，最高的享受與快樂就像是榮譽、和德性。無論是科學家還是哲學家，都會研究這類的對象。

幸福、德性、榮譽，研究這些就是倫理學的工作。

>>> 即便我能知道有些幸福快樂可能會是empty的結果，好好的去尋找，找機會填補那些遺憾會修復的快樂，畢竟是沒有更像這種工作是我所期望的那樣了。

Application to the Mind

CTM (computational theory of Mind) + RTM (representational theory of Mind) = CAR (computational account of Reasoning)

RTM的想法有二層。第一層是算機的概念：心理狀態是表徵的(representational)。第二層是語言的概念：這類歷程包含了一串符號的表徵，既有語意也有語法的特徵，就像電腦上的數學記號所做的計算。

這個主張如果和哲學有關的話，也是與CAR有關。根據CAR，推想(reasoning)是由符號的語法性質做出的因果關係，也就是思維語言(language of thought, LOT)或是心理語言(mentalese)。

形式化(formalization)和算機(computation)也有一些些(可能是 a little 或 more)哲學上的貢獻：我們獲得一些方法，可以將符號的語意性質寫成語法上可運作的推論規則。當然，指的是這些推論在可能成立的情況下，伴隨著它的語意也在直覺上可以呈現出來。

從語意進程到語法的階段，圖林算機的概念大大地顯示出，我們的語法和這些進行著的因果推論是可能被設計出來，成為可計算賦值與形式化其他算式的機器。

The Notion of "Formal Techniques" and "Computation"

"操作記號"和"計算"的根本概念是在數學的成果上獲得而來。首先，在十九世紀末二十世紀初，數學對於幾何的探討，以及研究歐氏幾何的第五公設(平行公設：通過直線外的一點，且與此直線平行的直線，只有一條) 這類的成果，促成一些"形式化語言"的研究與發現過程。

在當時，企圖證明第五公設一直是許多數學家的工作，不過，我們關心的主題在於他們研究那些清晰而不證自明的公理，還有那些加上去的推論規則，所帶來的成果。Frege、Hilbert、Peano、Gauss，試著尋找既不違反數學上的理由，又和我們自然的語意直覺相容的推論與形式化策略。

簡單而言，我們的自然語言的語意關係，在直覺上有些特殊的地方，但無論如何，重要的是它們必須能夠被形式化，成為像幾何學的公理，加上推論規則，以便我們的自然語言也能夠在相當的語法規則下保存它們自己的表達式。希爾伯特的成果在幾何的研究，羅素與懷海德則是在算述規則上；直到最終他們都是相當成功的，就像心理學的邏輯行為主義；不過，哥德爾不完備定理則是在最後畫下句點。

另外一個重要的是，數學家們清楚地區別出：有一些方程式是"可計算的"(computable)，這些方程式可以藉由我們設計它的運作來成為(being)可被決定和賦值的結果(例如 2x+1=y ，給出x 或y 就可得出其他值的結果)。

換言之，並不是所有方程式都是可被計算的。Alan Turing ，圖林設計了一個 "算機" (computing machine)，這臺算機可以做出2x+1=y 這類的工作，圖林他設想，一堆可計算的方程式等值(equivalent)於另一堆賦值的方程式，藉由一些有限的步驟，我們可以設計出這類算機。重要的是，任何輸入(operations)必須在語法上是可以機械地複製的。這個工作必須仰賴先前數學家們研究公理與推論規則，加上語意與與法的研究成果。

形式化和計算，這兩件工作因而變得相關性高：形式化的語言可以規則地由數學的方式，機械地複製。圖林認為，算機總有一天能夠像人類一樣，做出人類也能做的工作-至少在"複製"這件事情，當今的電腦真的做得很好了。當然，反對這類想法的人會認為，算機做出來的不過就是"複製"了一些東西罷了，他只是再製人們的東西而已。

fifty question of philosophy-Other minds

Zombies are frequent guests in the long-running philosophical debate know as the 'problem of other minds'.

I know that I have mind, an inner life of conscious experience, but the content of your mind is private and hidden from me; all I can observe directly is your behaviour. Is that sufficient evidence on which to base my belief that you have a mind like mine?

To put it more colourfully, how do I know that you are not a zombie like the ones described above - exactly the same as me in terms of behaviour and physiology and yet not conscious?

事實上，很少哲學家會去強烈質疑其他人是僵屍 - 也就是沒有心靈 - 不過，提出這樣的問題: "除了我之外的別人是否有心靈?" 是可以的。為什麼呢?

回想一下笛卡兒回應懷疑論的問題上，在第六沉思(sixth meditation)當中，笛卡兒論證了"我"是不可再懷疑的，根據"我"的獨特擷取訊息的能力，除了自己之外，其他人不能取代"我"有這種privileged access的能力。此外，無論怎麼懷疑"我正在思考"這件事，「我懷疑『我正在思考』」仍然會是一個我正在思考的實質命題。

回到other minds的問題，笛卡兒提供我們一個主張自己有心靈的理由，但是，擁有心靈還不夠；假設J是沒有心靈的機器人，我們透過有效的溝通程序和J進行互動，我們的行為J也都能夠做到；那麼J真的沒有心靈嗎?

笛卡兒的主張將心靈與外在區分為截然不同的「心」與「物」，稱為心物實體二元論；並且主張心物之間不會有因果交互作用。不過這類主張和我們的直覺並不相容。如果心物之間沒有因果交互作用，我們能夠感覺到「痛」會變得太神祕了點，但這不是一件太過神秘的事情，對當代的神經科學研究來說。

fifty question of philosophy-The ship of Theaeus

假設一年前張三買了一部腳踏車，取名「風火輪」，它是由364個零件所組成的。可是張三有一個奇怪的保養腳踏車的方法，他每天輪流替車上一個好的零件更換一個同樣的、全新的零件。這樣一年下來，車上的每一個零件都被換下來了，而且被換下來的零件都是沒有壞的。

(i)經過一年之後，風火輪的所有零件都被換過，也就是說，現在腳踏車的零件，沒有一個是原來的零件。請問：在此情形之下，張三現在的腳踏車與一年前所買的風火輪是否為同一部腳踏車？為什麼？

(ii)如果我們把張三在這一年間所換下來的風火輪的零件，又重新組裝起來，請問：這部重新組裝的腳踏車與張三現在的腳踏車，哪一部才是風火輪？為什麼？

Identity crises:

It isn't just a problem with cars and ships. People change enormously over a lifetime. Physically and psychologically, there may be very little in common between a 2-year-old toddler and doddery 90-year-old who's taken his place 88 years later. So are they the same person? If they are, what makes them so? It matters - is it just to punish the 90-year-old for something he did 70 years earlier? What if he doesn't remember it? Should a doctor allow the 90-year-old to die because that wish was expressed 40 years earlier by a previous version of himself?

人的等同問題隨時可見，無論我們是才出生到這個世界，或者我們仍是個嬰孩，從還只是一個胚胎兒有生命起，我們身為"人"的意思就有點複雜。那個還只上小學的我，以及即將成為父母的我，究竟有何不同？

Animals and brain transplants

一般上，我們不懷疑生物同一性：指現在的我與過去的我是同一款的生命有機體，總而言之，現在的我和過去的我是同一個人，因為我們還是同一個生命體。不過，想像一下：科技發達的緣故，你的腦可以換到我的身體，我的腦可以換到你的身體；可不是你的身體擁有一顆新的腦喔，是你的腦接上我的身體；這一樣來，這個"我"還是同一個我嗎?

由此，我們會認為某些什麼使得「我」是我，常是因為我的經驗、信念、記憶，而不總是因為我的物理組成部分，這個換腦的例子似乎就是這麼說的。

Psychological continuity

假如我們不同意生物同一性，也許我們可以說：我的信念、記憶等等，都參與我的心理歷程，這些信念和記憶並不會從開始到結束都一直發展下去，但它們與我的心理歷程會一直有某部分的重疊，也不違背我的心理歷程。從洛克提出這條人格同一性的原則後，近代哲學家們也對此提出了許多的困惑。

有一個稍微瘋狂的想法和困惑是：假想一個可以瞬間移動的機器，將你的"所有"都激化為分子流，傳送到地球以外的月球上，例如是從臺灣到月球表面；假如這個分子流很順利地將你傳送到月球表面，那麼無論是生物同一性或是人格同一性都會有什麼爭議，但是；假如這束分子流在傳輸過程出了一點差錯，你的一部分在臺灣，另一部分傳輸上了月球表面，那麼我們應該好好去想，人格同一性和生物同一性的原則是否成立？

fifty questions of philosophy-Reason and experience

How do we come to know things? Is it primarily through our use of reason that we acquire knowledge? Or does experience gained through our senses play the most significant role in the way we get to know the world? Much of the history of Western philosophy has been coloured by this basic opposition between reason and experience as the foundational principle of knowledge.

Specifically, it is the main bone of contention between two extremely influential philosophical strands - rationalism and empiricism.

我們如何得到認識這個世界？難道是理性引領的嗎？我們思考、我們想像、我們感覺到風的吹拂以及看見綠樹的蓊鬱，那些繁星點點的回憶，還有安安靜靜的蟲鳴？這些美好的事物，是否可以與知覺有所區別？長久以來，理性論者與經驗論者感興趣的課題，幾乎就圍繞在這些問題上。

不過，在進入討論理性論與經驗論之間的議題前，我們有一些準備工作要先做。

首先，熟悉一下重要的哲學詞彙，因為這些詞彙將成為我們討論問題的基本裝備：

priori，posteriori, 一般翻譯是先驗和後驗；

priori 它不需直接指涉到我們的經驗世界但是我們可以知道它, "2+2=4"便是一個明顯的例子 - you do not have to go out into the world to establish its truth。(雖然我覺得有些人會和我一樣不同意。)

posteriori，例如"木炭是黑的"，假設這句話為真，它就是後驗而真- something is only knowable，我們必須拿塊木炭看看才行，不然看圖也可以啦。總之，你得看過"木炭"這個"東西。

analytic，分析的，一個命題是分析的，指它已經包含了它的意思而不假其他被加上的訊息。例如"所有未婚女子都是可憐的"直指到現實的那些還未婚的女子，它就是分析的。(這是書上的例子，我覺得它是個奇怪的例子。)

syntheic，綜合的，一個命題是綜合的，指它包含了不同的概念引導主要概念(包括錯誤訊息)。所以，你得去看看那些未婚女子是否很可憐。(做這種事太無聊了吧，好像狗仔。)

necessary，必然的，必然為真的意思是，在所有狀況下都為真，或者說在所有可能世界中都為真。

contingent，偶然的，偶然為真的意思是，它是真而且它並非和這世界的事物完全一樣。例如"多數男孩都是調皮的"只是偶然為真，可能為真或者不為真。(為什麼女子和男孩的例子差這麼多-_-|||)

康德，提出有"必然的先驗分析命題"，和"偶然的綜合後驗命題"。這兩個命題的區別，舉例而言，"2+2=4"這個命題，對某些人而言是必然的先驗分析命題；掌握了加法規則，即使機器也可以做出這道命題；而對某些人而言，它是偶然的綜合後驗命題；"2"在哪裡呢? 難道我不是藉由一顆再一顆的蘋果認識它嗎？

爭論這類數學命題似乎一直都沒有消弱某些哲學家的熱情，不過，這裡最主要的問題還是：How do we know?

>>> 這類議題還蠻有趣的，以前在知識論課上，大家還吵成一團呢 :)

fifty questions of philosophy-brain in a vat

Imaging that a human being has been subjected to an operation by an evil scientist. The person's brain has been removed from the body and placed in a vat of nutrients which keeps the brain alive. The nerve endings have been connected to a super-scientific computer which causes the person to have the illusion that everything is perfectly normal.

But really all the person is experiencing is the result of electronic impulses traveling from the computer to the nerve endings.

這真是科幻小說的情節！你的腦被營養液豢養在一個vat裡，而你現在看見的桌椅、書和電腦螢幕都是超級機器刺激之下的幻影！

我們可以不相信自己是個桶中腦，大部分哲學家也不相信，但我們可以相信：我們自己可能是個桶中腦，如果是，我們就無法確定外在於我們的世界。

桶中腦由Hilary Putnam在1981年的《Reason, Truth, and History》提出。較早的源頭可追至Descartes在1641年的《Meditation on First Philosophy》當中的evil demon, 一般稱是惡魔論證or夢幻論證:

"I shall suppose... that some malicious demon of the utmost power and cunning has employed all his energies in order to deceive me. I shall think that the sky, the air, the earth, colours, shapes, sounds and all external things are merely the delusions of dreams which he has devised to ensnare my judgment."

類似的故事情節例如，《駭客任務》，主角尼歐被現實世界的人從母體創造的世界中救出(雖然他有點不情願)，發現他過去的記憶都只是虛幻不實的假象。

大部份的哲學家已經跟隨他們倆的腳步，也試圖躲避了懷疑論的陷阱。在Putnam自己的意義理論裡，他也試圖說明：意義不在我們大腦中，而是在大腦之外。然而，面對解決桶中腦之路仍然遙遠，當然不是不可能。

但我們也可以有一些反駁意見---假設的“未來“還沒有發生！我們也不會認為自己正在被複雜精密的電腦儀器操縱著。（但是這個反對意見不夠全面，因為桶中腦在位來是否為真不影響我們討論討桶中腦問題。）

現在，讓我們聊聊懷疑論。

懷疑論者，指的是那些傾向去探討一般人的信念以及普遍接受的想法的人。但是這和哲學上的懷疑論不同。我們必須先將一般而言的懷疑論與哲學上的懷疑論區分清楚。哲學的懷疑論並不是指我們知道我們不知道任何事，至少絕不是因為我們很明顯地在替自己辯護。(這段有人看得懂嗎?)

無論如何，懷疑論質疑的是，我們相信我們知道很多事情，但我們有什麼好理由替這些我們所相信的事情辯護呢?我們有可能從基礎上就替這些我們自認為所知的知識辯護嗎?假設我們已知的都是由外在世界，通過感官和感覺獲得，我們有什麼好理由認為這些已知都是不會錯的? 《駭客任務》當中，莫斐斯問尼歐的那一句便是這類的態度：如果我們無法區分夢境與現實，夢境就像現實，現實如同夢境，那麼我們如何從夢中醒來?

哲學領域中的知識論便是在做著類似的工作：掌握我們已知以及我們如何知道，研究這些條件與它們的等同關係，這便是研究知識與考察知識的工作。這就像幾千年以來哲學家都試圖去回答懷疑論的問題一樣，Descartes的哲學果實是截至目前為止，很明顯地尚未被懷疑論擊倒，仍然屹立不搖的回應懷疑論成果，後續的哲學工作仍然進行著，並且將更加深入探討知識的問題。

fifty questions of philosophy-Plato's cave

The Allegory of the Cave appears in Book 7 of Republic, Plato investigates the form of the ideals state and its ideals rulers.

His justification for giving the rein of government to philosophers rests on a detailed study of truth and knowledge.

一旦我們手與腳的枷鎖解開之後，因而得以走出自出生便禁錮著我們的洞穴；這眼前的世界是光彩炫目，以前洞穴中偶像所透過的影子成為眼前的真實事物，比如太陽、天空的雲。

洞穴意味著柏拉圖主張，在我們這個一切事物都在改變的世界之外，還有一個一切都不會變動的"the realm of being"的世界。

因而相對於一顆紅色的蘋果來說，應該還存在另一顆不會改變的，同樣也是一顆「紅色的蘋果」，也就是紅色蘋果的form, 或稱理型或Ideal。

從理型引申的哲學問題是共相(universals)的問題。共相的爭論是歷史已久的形上學問題，簡言之；主張有不會變動的世界當中的事物，例如不會變的，，「紅色」、「高的」，持這類觀點的人稱為唯實論者(universals realism)，而反對有這類事物的論者，認為所謂不會變的「紅色」只是出現在我門語言中的語言項目(卡納普)，它們占據時間與空間，並不是什麼共相，而是殊相(particular)，我們稱他們是唯名論者(nominalism)。當然這類的爭論在近代已經轉為實在論者與反實在論者的哲學論戰，也衍生出許多精彩哲學討論。那些主張在這個現實世界(actual world)之外還有其他X存在的論點，稱為實在論者(realism)，而反對又這類事物的人則稱為反實在論者(anti-realism)。

關於此洞穴之喻之於柏拉圖與它的老師蘇格拉底的故事，可參照一般哲學故事，在此不贅敘。