笛卡兒我思故我在是近代思想的啟蒙點，也是歐洲理性時代的開始。本文分享《沉思錄》第二篇的原文及中譯，介紹他如何找到1個保證不會被騙的原點。
一、沉思錄第二卷
主要內容
- 延續第一沉思的懷疑：昨天我把所有能懷疑的東西都懷疑掉了，現在我陷在懷疑裡，要找一個絕對確定的起點。
- 尋找阿基米德的「支點」：只要有一個不動搖的確定點，就能從那裡建立新的知識，類似於笛卡兒數學的基礎。
- 懷疑感官與身體：我看到、聽到、觸到的一切都可能是幻覺或欺騙，包括我的身體也可能不存在。
核心推理
- 即使被欺騙，我也存在：假如有一個強大的騙子一直欺騙我，那我至少必然「存在」才能被欺騙。
- 「我思，故我在」：只要我在思考、懷疑、被騙，那麼我就「在」。這句話無論何時被我想起或說出來，都必然是真的。
- 我究竟是什麼？：不是身體，不是空氣、火焰或氣息，而是一個「思考的東西」——心靈、靈魂、理解、理性。
蜂蠟例子
- 感官的變化：蜂蠟加熱後味道、顏色、形狀、觸感都變了，但我們仍認為它是同一塊蜂蠟。
- 心靈的把握：這表示蜂蠟的「本質」不是那些感官屬性，而是「延展性、可變性」等抽象特徵；而這些不是靠想像，而是靠心靈的知覺（理智的判斷）才明白。
- 知識的來源：所以對物體的真正認識不來自眼睛、觸覺或想像，而來自「心靈對本質的檢視」。
如果要用一句話抓重點：
笛卡兒在第二沉思裡確立「我思故我在」作為絕對確定的基礎，並藉蜂蠟的例子說明真正的知識來自心靈的判斷，不是感官或想像。
二、笛卡兒我思故我在
笛卡兒我思故我在是近代哲學最經典的思辯，甚至還可能延伸到自由意志哲學的範疇。它首先延續懷疑一切的惡魔論證開始，試圖找尋無法被懷疑之物。於是他發現即使是被欺騙，必須有個欺騙的對象存在，因此，只有我存在才會被欺騙，我思，故我在。接著笛卡兒便以自我思考為起點，繼續推究這個我思的性質可能為何。具體說明如下：
阿基米德原點
當一切都被懷疑，當世界如夢般模糊，我仍能確定一件事——我正在思考。即使有騙子欺瞞、幻覺迷惑，懷疑本身仍是思考的證明。於是我在混沌中抓住那唯一不會被推翻的真理：「我思，故我在。」這是存在的第一道光，它就好像阿基米德可以推動地球的支點，從此理性得以重建世界。
自我究竟為何
既然存在無可否認，那我究竟是誰？不是手、不是眼、不是血肉的總和，因為這些都可能是幻覺。真正的「我」是一個能懷疑、能理解、能意志、能想像的思考之物。身體或許會變，但思考的存在才是我自身的根。
感官與心靈世界
當我凝視一塊蜂蠟，觸覺、氣味、形狀皆可改變，但我仍認為它是同一物。感官告訴我的並非真理，唯有心靈理解其延展與變化的本質。於是我明白：世界的確存在，但它的真實不是在眼前，而在我思考的心靈之中。
三、中文重點摘錄
第二沉思：關於人的心靈本質，以及它比身體更容易被確證的理由
昨天的沉思讓我陷入極深的懷疑，這些懷疑如此深刻，以至於我無法忘記。雖然我不知道該如何解決它們，但我感覺自己像被拋入一個深不見底的海溝，既摸不到底，也浮不上水面。
然而，我決定再試一次。我要像昨天那樣，徹底拋開一切可懷疑的東西，把它們當作全然虛假，直到找到某個確定無疑的真理。即使找不到其他真理，至少也要確定「一切都不確定」。
阿基米德說，只要有一個穩固的支點，他就能撬動整個地球。如果我能找到哪怕一個確定無疑的真理，也許我就能由此推動更大的發現。
從懷疑開始
因此，我暫時假定我所看到的一切都是假的；我相信記憶中那些事物都不真實。我假設自己沒有感官，沒有身體，形狀、空間、運動、位置，全是虛構。那麼，什麼才是真的？或許只有這一點：「沒有任何確定的東西」。
但我為什麼要認為真的「什麼都沒有」呢？難道沒有一個上帝（或者不管怎麼稱呼他），是他讓我產生這些念頭？或者也可能是我自己創造了這些想法。如果是這樣，那我就必然「是某個東西」。
我思故我在
剛才我懷疑自己有沒有身體、感官；但我能否存在而沒有它們？我可以懷疑世界上沒有天空、沒有大地、沒有靈魂、沒有身體，甚至懷疑「我自己是否存在」——但若我能懷疑，至少必然有個「我」在懷疑。
再想想，即使有一個極強大而狡猾的欺騙者(著名的笛卡兒惡魔論證)，不斷欺騙我，只要他能欺騙我，那我就一定存在；因為若我不存在，他又怎麼能欺騙我呢？
所以，只要我在想、在懷疑、在被欺騙——我就存在。
因此，我可以立下這個原則：每當我說出或想到「我存在」這句話時，它必然是真的。
我是誰？
但我還不完全明白「我」是什麼。為了避免誤解，我要重新檢查過去我對自己的看法，把所有可懷疑的部分去除，只留下真正確定的。
以前我認為自己是一個「人」。那麼，什麼是人？一個「有理性的動物」？不，這定義太抽象。與其玩文字遊戲，不如直接看：當我自然地想到「我」時，腦中浮現什麼？
我想到我有臉、有手、有身體；我能吃、能走、有感覺、能思考。這些動作中，前者屬於身體，後者屬於靈魂。但那時我對「靈魂」的概念很模糊，只覺得它像風、火、空氣之類的東西在體內流動。
懷疑身體的存在
我對身體的理解是：凡有形狀、佔空間、能觸摸、能移動的東西，就是「身體」。而身體本身不會思考、感覺或運動，除非被別的東西推動。
但既然我假定有一個極強大的欺騙者要迷惑我，那我又怎能確定我真的有這樣的身體？我想不出答案。於是我只能暫時放下。
尋找不被懷疑的我
我曾把「思考」歸於靈魂。那麼，若身體不存在，我是否仍能思考？我不能確定我有感覺、有動作，但我確定我能懷疑、能理解、能意願、能否定、能想像。
所以，我確實存在，並且我是一個「思考的東西」。
我存在的時間，就是我思考的時間。當我停止思考時，我也可能不再存在。
因此，我不是身體，不是氣體，也不是火或風，而是一個「心靈」、「靈魂」、「理性」或「理解」。
想像與理智的區別
我確定我存在，但仍不確定我是什麼樣的存在。假如我用想像去理解自己，那是錯的。因為「想像」只是在思考有形的東西，而我現在確定「我」不是任何形體。
所以，「想像」無法幫我理解自己，反而會讓我更混亂。要認識「我」的本質，必須靠「理智」而非「感官」或「想像」。
我是思考的東西
那麼，「思考的東西」是什麼？
它就是能懷疑、理解、肯定、否定、願意、不願意、想像、感覺的東西。這些能力都屬於我。即使我睡著、即使造物主欺騙我，這些思考活動依然屬於我。
所以，我就是那個懷疑、理解、想像、感受的存在。這是無法分離的真理。
蜂蠟的例子
但我仍覺得，物體似乎比我自己更明確。讓我舉個例子——蜂蠟。
剛從蜂巢取下的蜂蠟，有甜味、有花香、有顏色、有形狀、能摸到、能發聲。可是當它被加熱後，味道、氣味、顏色、形狀都改變了——它變軟、變熱、變大，甚至敲擊也沒聲音。
那麼，這還是同一塊蜂蠟嗎？當然是。大家都承認這點。那麼，蜂蠟的本質是什麼？
不是它的味道、顏色或形狀——那些都變了。它真正的本質，是「延展、可變、佔據空間」。
然而，這些特徵我並不是靠「想像」理解的，因為我無法想像蜂蠟所有可能的變化。
所以，我不是用眼睛或想像去理解蜂蠟，而是用心靈去「領會」它的本質。
結論：理性高於感官
我由此明白，真正的認識並非來自感官，而是來自理智的洞見。蜂蠟的例子說明，即使感覺和想像都不可靠，理性仍能讓我確定存在與本質。
因此，我確定自己存在，作為一個「思考的存在」；而一切外在的物體與身體，都只能藉由心靈的理解被真正認識。
四、沉思錄卷二原文
Meditation II
On the nature of the human mind, and that it is more easily known than the body
Yesterday’s Meditation has cast me into such profound doubts that I shall never forget them; and yet I do not see how to resolve them. As if I had suddenly plunged into a deep gulf, I am so astonished that I can neither touch the bottom nor swim at the surface.
Nevertheless, I will endeavor again and follow the path I set out yesterday: I shall reject whatever admits even the slightest doubt, as if I had discovered it to be entirely false, and I shall press on until I find some certainty—or, if nothing else, at least this certainty: that there is nothing certain.
Archimedes required only a firm and immovable point in order to move the whole Earth; so in this grand undertaking I may hope for great results, if I can discover but the smallest thing that is true and indisputable.
Hence I suppose that all the things I see are false, and I believe that nothing exists which my deceitful memory presents to me; it is evident that I have no senses, that a body, figure, extension, motion, place, etc., are mere fictions. What then is there that is true? Perhaps only this: that there is nothing certain.
But how do I know that there is nothing distinct from those things I have just listed—things of which I have no reason to doubt? Is there no God (or whatever name I may give him) who has placed these thoughts into me? Yet why should I think so, when perhaps I myself am their author? On that account, then, must I not be something? Just now I denied that I had any senses or any body. Wait—am I so bound to body and senses that I cannot exist without them? But I have persuaded myself that nothing exists in the world: no heaven, no earth, no souls, no bodies. Then why not that I myself do not exist? Yet surely, if I could persuade myself of anything, I was.
But there is—I know not what sort of deceiver, exceedingly powerful and crafty—who always tries to deceive me. Without doubt I exist if he can deceive me. Let him deceive me as much as he can, yet he can never make me not be while I think that I am. Therefore I may establish this principle: whenever the sentence “I am, I exist” is uttered or conceived by me, it is necessarily true.
But I do not yet fully understand who I am that necessarily exists, and I must take care lest I foolishly mistake some other thing for myself and thus be deceived about this thought, which I uphold as the most certain and evident of all.
Wherefore I will again recollect what I formerly believed myself to be, before I undertook these Meditations, and strip away whatever can be disproved by the above reasons, so that in the end only that which is true and indisputable may remain.
What then did I formerly believe myself to be? A man. But what is a man? Shall I answer, a rational animal? By no means—because one could then ask, what is an animal? and what is rational? From one question I might fall into still greater difficulties. Nor do I presently have time to quarrel about such subtleties.
Rather I will consider what presented itself freely and naturally to my thoughts when I asked myself, “What am I?”
The first thing I see presenting itself is that I have a face, hands, arms, and this whole frame of parts which is seen in my body, and which I call my body.
The next thing represented to me is that I am nourished, that I can walk, that I have senses, and that I can think; these I assigned to my soul. Yet what that soul was I did not fully conceive; or perhaps I supposed it to be a small thing like wind, fire, or air, infused into my stronger parts.
Truly I did not doubt that I understood the nature of my body correctly; and if I were to attempt to describe its nature as I conceived it, I would thus explain: by “body” I mean whatever is capable of figure, or can be contained in a place, and thus fills space, excluding other bodies from occupying the same. I mean something that may be touched, seen, heard, tasted, or smelled, and that is capable of various motions and modifications—not from itself but from something else moving it. For I judged it contrary (or rather above) the nature of a body to move itself, or to perceive or think; and yet I marveled that I found these operations in certain bodies.
But now, since I suppose a certain powerful and (if I may call him so) evil deceiver who exerts all his efforts to deceive me in everything, how can I affirm that I have any of those things which belong to the nature of a body? Hold—let me consider, let me reflect—I find no answer, and I am weary of repeating the same things in vain.
Which of those faculties did I attribute to my soul—nutritive or locomotive? But now, seeing I have no body, these too are mere delusions. Was it the sensitive faculty? But that also cannot operate without a body. And I have seemed to perceive many things in sleep of which afterwards I understood that I was not sensible. Was it the cognitive faculty? Here I have discovered it: it is my thought. That alone cannot be separated from me. I am, I exist—that is certain. But for how long am I? Why—I am as long as I think. For it may be that when I cease to think, I may cease to be. Now I admit of nothing except what is necessarily true. In short, then, I am nothing but a thinking thing, that is to say, a mind or a soul or an understanding or a reason—terms I previously did not understand. I am a real thing, really existent—but of what sort? I have just said: a thinking thing.
But am I nothing else besides? I will consider—I am not the structure of parts called a man’s body; neither am I some thin air infused into those parts, nor wind, fire, vapor, or breath, or anything I can feign. All these I have supposed not to exist. Nevertheless, my position stands firm: nevertheless, I am something. Perhaps it so happens that those very things I suppose not to exist (because to me unknown) are not truly distinct from that very self which I do know. I cannot tell; I will not dispute that now. I can only opine concerning those things I have some knowledge of. I am sure that I exist. But who am I whom I thus know? Clearly, the knowledge of me (precisely taken) does not depend on those things of whose existence I am ignorant; therefore it does not depend on anything which I can feign by imagination.
And this very word “feign” reminds me of error: for I would feign indeed, if I were to imagine that I am anything. To imagine is nothing but to think of the shape or image of a corporeal thing; but now I certainly know that I am, and I also know that it is possible that all these images, and generally whatever pertains to the nature of a body, are only deluding dreams. Considering this, it would be no less foolish for me to say, “I will imagine so that I may better understand what I am,” than to say, “At present I am awake and perceive something true, but because it does not appear clearly enough, I will endeavor to sleep, so that in a dream I may perceive it more evidently and truly.”
Therefore, I know that nothing I can grasp by my imagination belongs to the notion I have of myself, and I must withdraw my mind from those things so that it may more distinctly perceive its own nature.
Let me then ask: what am I? A thinking thing. But what is that? That is something that doubts, understands, affirms, denies, wills, refuses, imagines, also senses. These are certainly not a few properties, if they all belong to me—why should they not? Am I not that same being who now doubts almost everything, yet understands something, affirms it as true, denies all else, wills to know more, does not want to be deceived, imagines many things unwillingly, and takes many things as coming via my senses? Which of these faculties is not as true as that I exist, even if I should sleep or my Creator strive to deceive me? And which of them is distinct from my thought? And which can be separated from me? Because I am the same being who doubts, understands, and wills is so evident that I cannot more manifestly explain it. I am also the one who imagines—though perhaps nothing that can be imagined is true, yet the very power to imagine is real and is a part of my thought. Finally, I am the same being who is sensitive—or perceives corporeal things via the senses. Even if I suppose I am asleep and that what I see, hear, or feel now are false, yet I know that I see, hear, and am heated; that cannot be false. That which in me is properly called sense is really my thought in a broader sense.
By these considerations, I begin somewhat more clearly to understand what I am. Yet it seems—and I cannot help thinking—that corporeal things (whose images are formed in my thoughts and which I perceive by my senses) are more distinctly known than that confused notion of myself which imagination cannot furnish. And yet it is odd that doubtful, unknown things, distinct from myself, should be perceived more clearly than a thing that is true, than a known thing, or myself. But the reason is that my mind loves to wander and will not constrain itself within the strict bounds of truth.
Let it wander, then, and once more let me give it free rein, so that later, having it bound and governed properly, it may more easily be reined.
Let me consider those things I formerly conceived as most evident—that is, particular bodies we see or touch, not bodies in general (for general concepts are usually confused), but some individual body. Let us take, for example, this piece of beeswax. It was just now taken from the comb. It still has taste, smell, color, shape, size; it is hard, cold, easily felt; and if you strike it with your finger, it makes a sound. In short, it has all the qualities suited to the most perfect notion of a body.
But behold—while I am speaking, I bring it near the fire; its taste is dissipated, its smell disappears, its color changes, its shape is altered; its bulk is increased, it becomes soft, it is hot, it can scarcely be touched; and though you strike it, it makes no sound. Is it still the same wax? Surely it is; no one denies it. But which of the perceived qualities remained? None—the taste, smell, color, shape, sound have all vanished, yet the wax remains. Perhaps all I now think of is that the wax was not the taste of honey, the smell of flowers, the whiteness, shape, or sound, but rather a body which appeared with those modifications then but now differently. But strictly speaking, what do I conceive? Rejecting everything that does not truly pertain to the wax, I see only this: something extended, flexible, and mutable. But what is meant by “flexible, mutable”? Is it that I imagine it round and square, square and triangular? No—for I conceive it to be capable of innumerable such changes, though I cannot imagine all of them. Thus that notion of mutability does not arise from imagination. What then is “extension”? Even extension is not strictly imagined—to imagine all its possible expansions would exceed my capacity. So I must admit that I cannot imagine what this wax is, but only perceive it with my mind. (I speak of this particular wax; for of wax in general the notion is clearer.)
So what wax is this that I conceive by the mind alone? It is the same which I see, touch, imagine, and initially judged. Yet the perception of it is not by sight, touch, or imagination; it never was those. The perception is inspection or intellectual apprehension—an act of the mind alone. Sometimes that act is imperfect and confused, as before; now it can be clear and distinct when I consider more fully the nature of the wax.
Meanwhile, I cannot but marvel at how prone my mind is to error; though I revolve these matters silently and without speech, I become entangled in mere words and nearly deceived by customary expressions. We often say we see the wax itself, not that we judge it present from its color or shape; from that style of speech one might immediately conclude that wax is known by the eye, not by the mind’s inspection alone. I would have made that mistake had I not chanced to look through the window and see men walking in the street. I say that I see those men as commonly as I say I see the wax; yet I see nothing but hair and garments—which may conceal mechanical automata—I judge them to be men by my judicative faculty, my soul. It is unworthy of one who aims to be wiser than the common man to draw doubt from those popular expressions.
Therefore, let us proceed to ask: did I perceive the wax more perfectly and evidently when I first looked at it and believed that I knew it by outward senses or by common sense (that is, by imagination), or do I now understand it better, after more diligent inquiry into what it is and how it may be known? Surely one would be foolish to doubt which perception is truer. What was in my first perception that was distinct? What part of it seemed not shared by other animals? But now, when I separate the wax from its sensory properties and consider it as stripped of coverings, I can truly perceive it with my mind—though my judgment might still err.
But what shall I say about my mind, or myself? (For so far I admit nothing to belong to me except the mind.) Why should I, who seem to perceive this wax so distinctly, not know myself more truly, more certainly, more distinctly, and more evidently? If I judge that this wax exists because I see it, then it will be yet more evident that I exist because I see the wax; for it may be that the wax I see is not real, and it may be that I have no eyes at all; but when I see—or in other words, when I think that I see—it cannot be that I, who think, do not exist. The same applies if I judge that the wax exists because I touch or imagine it. What is said of wax may be applied to all external things.
Moreover, if the notion of wax becomes more distinct once it is more fully considered—not only by sight or touch but by other causes—how much more distinctly must I acknowledge that I know myself, since all the reasoning that helps me understand wax or any body also increases the evidence about my mind. And there are far more things in the mind itself by which its notion may be made more distinct, so that those drawn from bodies are scarcely worth mention.
And now behold: I have reached by my own effort the place I sought. Since I have discovered that bodies themselves are not properly perceived by senses or imagination but only by understanding—and hence they are not perceived because they are seen or touched, but because they are understood—it plainly appears to me that nothing can possibly be perceived by me more easily or more evidently than my mind.
But because I cannot swiftly shake off the habits of my former opinion, I will stop here, so that this new knowledge may be more firmly fixed in memory as I meditate further.
贊贊小屋讀書的好處：
笛卡兒演繹法、蘇東坡人生態度、西遊記線上看、封神演義線上看、白蛇傳小說線上看、妙法蓮華經功效。
