Notes on <Meditation on First Philosophy> by Rene Descartes

2020-04-24 0 views

Background

Rene Descartes’ <Meditation on First Philosophy>, especially the first two meditations, where the famous quote I think therefore I am(Cogito, ergo sum)’ comes from, have had a huge impact in the history of philosophy, they are often considered as the mark for modernity and an unavoidable first step for any modern philosophical thinking. The proposition “I think therefore I am” became a fundamental element of western philosophy, since it tries to form the indubitable foundation of knowledge in the face of radical doubt. This book also brings the mind body problem into people’s attention, and proposed the thesis known as Cartesian Dualism or “mind-body dualism”.

Meditations I - On what can be called into doubt

Summary: Meditation I tries to find out the foundation of the knowledge by doing a radical and methodological doubting on all things until we find something that is indubitable.

Descartes is aware that he has taken false opinions to be true before and would like to demolish all of the opinions and start over from foundations. To do this, it is not necessary to show all the beliefs are false one by one, all we need to do is to undermine the basic principles which all the former beliefs rested. The foundation of the former beliefs is the senses, which may deceive people occasionally. For example, we may have similar experiences sleeping and while awake and there is no reliable way to distinguish between being awake from being asleep.

However, even though I am asleep, the visions in my mind should come from real things instead of being entirely new. There are elements out of which we make all our mental images, including body and extension, shape, quantity, size and number, the places they can be in and the time through which they can last. So it seems like arithmetic and geometry contain something certain and indubitable.

But how do I know that it is not God who deceives me every time I do arithmetic or geometry? You may say that because God is supremely good, but if that is the case, that is, if we can expect God to stop me from being deceived all the time, we should also be able to expect God will stop me from being deceived even occasionally, but clearly that is not the case.

People may deny the existence of a powerful God but that only makes it more likely for me to be deceived all the time. So in the future if I want to discover any certainty, I must withhold the assent from these former beliefs as carefully as obvious falsehoods.

To conquer the habit of old beliefs, we shall suppose that some malicious, powerful, cunning demon is deceiving me all the time. And I shall stubbornly persist in this chain of thought. Even if I can’t learn any truth, I shall at least not to accept false believes.

Meditations II - The nature of the human mind, and how it is better known than the body

Summary: There is one thing that can not be doubted, which is I, a thinking thing, exist.

I will suppose that everything I see is fictitious and there is a supremely powerful and cunning deceiver who deliberately deceives me all the time. Even then, if he is deceiving me then undoubtedly I exist. So, I am, I exist, must be true whenever I assert it or think it.

But, what is this “I” that exist? It is a body and a soul when I think about it. A body is whatever has a definite shape, and position and it can’t start up movements by itself. But the body is subject to doubt when I am supposing there is a malicious deceiver. Since I can perceive things without body when I am dreaming. Thinking or thought is the one thing that cannot be separated from me. I am simply a thing that thinks, a mind, a soul, an intellect or reason. I am a thinking thing.

But I still can’t help thinking that bodies, which I realized are doubtful, unknown and foreign to me, are clearer than I know what is true, namely my own self.

Let’s consider an example of wax, its color, shape, size are plain to see, it is hard, cold and can be handled easily. However, when I hold it near to fire, the color, shape, size all changes, and it becomes liquid and hot. But it is still the same wax. Evidently it is not any of the features that the senses told me that I understood clearly, that makes the wax wax. If we take away everything that doesn’t belong to the wax, that it could be without, what is left is merely something extended, flexible and changeable. The nature of the wax isn’t revealed by my imagination, but is perceived by the mind alone. My perception of the wax seemed to be a case of vision, touch and imagination, but is actually purely a scrutiny by the mind alone. After I enquired carefully into the nature of the wax, my perception is more perfect and clear than before, when I knew it through my senses.

Meditation III - God

Summary: I couldn’t exist with the nature that I have - that is, containing within me the idea of God - if God didn’t really exist. And God is the one that has no defects and has all perfections that I can’t grasp but can somehow touch with my thought. And it also makes it not possible for him to be a deceiver since deception depend on some defect.

I am certain that I am a thinking thing. Doesn’t it tell me what it takes for me to be certain about anything? Now I am able to lay it down as a general rule that whatever I perceive very vividly and clearly is true.

The only reason I can find or doubting arithmetic or geometry is that there is a supremely powerful God that is deceiving me. I need to rule out this possibility before I can be certain about anything else.

First I need to classify my thoughts into different kinds and ask which kinds can be said to be true of false. I can have ideas of things, emotions or judgments. The only kind of thought where I must watch out for mistakes are judgments. And the mistake they most commonly involve is to judge that my ideas resemble things outside me.

Among my ideas, some seem to be innate, some to be caused from the outside and others to have been invented by me. My understanding of what a thing is derives from my own nature, which is innate. My hearing or seeing comes from things outside me. Sirens and the like are my own inventions.

But my main question concerns that ideas that comes from things outside me, why do I think they resemble these things. The reason is that by experience I know that these ideas don’t depend on my will, and thus don’t depend simply on me. Nature has taught me to think that the ideas are coming from things outside me, and I have a spontaneous impulse to believe it, not that I am shown its truth by some natural light. Things are revealed by the natural light are not open to any doubt, because no other faculty that might show them to be false could be as trustworthy as natural light. But my natural impulses have no such privilege.

Then although these ideas don’t depend on my will, it doesn’t necessarily follow that they must come from things outside me, it could come from faculty of mine other than my will. Similarly, the natural impulses, though opposed to my will, come from within me, which provides evidence that I can cause things that my will does not cause.

Finally, even if these ideas do come from things other than myself, it doesn’t follow that they must resemble those things. For example I can have two conceptions of suns, one from sense, which suggests the sun is small, one from astronomical reasoning, which suggests the sun is large. And obviously these ideas cannot both resemble the external sun.

The ideas that represent substances amount to something that has more representative reality than the ideas that merely represent modes(qualities). It’s obvious by natural light that the total cause of something must contain at least as much reality as does the effect. Two things follow from this: 1. that something can’t arise from nothing, 2. that what is more perfect can’t arise from what is less perfect. And this is true for both actual reality but also for representative reality of ideas.

Any idea that has representative reality must surely come from a cause that contains at least as much intrinsic reality as there is representative reality in the idea. It might be thought that the reality that I am considering is merely representative and is caused by representative causes but there can’t be an infinite regress and eventually one must come back to an idea whose cause isn’t merely representative.

My conclusion is: if I find that some idea of mine has so much representative reality that I am sure the same reality doesn’t reside in me, either straightforwardly or in a higher form, and hence that I myself can’t be the cause of the idea. Then because everything must have a cause, I would necessarily follow that I am not alone in the world: there exists some other thing that is the cause of that idea. If no such idea is to be found in me, I shall have no argument to show that anything exists apart from myself.

Apart from the idea of myself, there are ideas that variously represent God, inanimate bodies, angels, animals and finally other men like myself. My ideas of other men, animals or angels can easily be understood to be put together from the ideas I have for myself, of bodies and of God.

Examining all the ideas I have, I found that only the idea of God, a substance that is infinite, eternal, unchangeable, independent, supremely intelligent, supremely powerful, which created myself and anything else that may exist, can’t have originated from me alone. So God must necessarily exists. It is true that my being a substance explains my having the idea of substance, but it does not explain my having the idea of infinite substance, that must come from some substance that is itself infinite.

There might be objection that the idea of infinite comes from the negation of the idea of finite, however, I clearly understand that there is more reality in an infinite substance than in a finite one and hence my perception of the infinite is in some way prior to my perception of the finite, i.e. myself. How could I grasp the idea that I lack something unless I had an idea of a more perfect being that enabled me to recognize my own defects by comparison? It does not matter that I don’t grasp the infinite, for it is the nature of the infinite not to be grasped by a finite being like myself, it is enough that I understand the infinite.

Meditation IV: Truth and Falsity

Summary: Meditation IV explore the reason why error exists, and the conclusion is that error comes from the will making judgments without the vivid and clear understanding revealed by intellect.

It is impossible for God to deceive me because of his nature. And he won’t give me a faculty of judgment that would lead me into error while I was using it correctly, which seems to imply that I can never be in error. However, we know by experience that it is not the case. The reason why I am given to errors is that I am in between God and nothingness. Error is not something real that depends on God, but is merely something negative, a lack, a defect.

Three helpful thoughts come to me when I think about why errors happen. (1). It is no cause for surprise if I don’t always understand why God acts as he does. (2). In estimating whether God’s works are perfect, we should look at the universe as a whole, not created things one by one. (3). My errors are the only evidence I have that I am imperfect. My errors depend on both my intellect and my will. The power of willing that God has given me is not the cause of my mistakes, nor is my power of understanding to blame. The source of my mistakes is the fact that my will has a wider scope than my intellect has, so that I am free to form beliefs on topics that I don’t understand, instead of suspending judgment when I am not intellectually in control.

Falsity and error are essentially a privation, and this privation has no need for help from God, because it isn’t a thing, a being. God is able to make me in the way that I always suspend judgment when I do not have enough understanding, but universe as a whole may have some perfection that requires that some parts of it be capable of error. If I restrain my will so that I form opinions only on what the intellect vividly and clearly reveals, I cannot possibly go wrong.

Meditation V: The essence of material things, and the existence of God considered a second time

Summary: Meditation V shows an ontological argument for the existence of God and answers some objections.

There are countless ideas that may not be called nothing, even if they don’t exist anywhere outside me, for example, propositions about arithmetic and geometrical concepts are clearly apprehended and certain. These leads to the conclusion that the mere fact that I find in my thought an idea of something x, and vividly and clearly perceive x to have a certain property, it follows that x really does have that property, and this can be applied to the proof of the existence of God as well.

It’s possible to separate existence from essence for a triangle, but for God, it is self-contradictory to think of God as not existing. That is, to think of a supremely perfect being as lacking a perfection, namely the perfection of existence.

Meditation VI: The existence of material things, and the real distinction between mind and body

Summary: Meditation VI shows that body exists, mostly by the premise that God would not be a deceiver and the idea of body is necessary to produce sense perceptions.

The remaining task is to consider whether material things exist. My faculty of imagination, which I am aware of using when I turn my mind to material things, also suggests that anything I perceive vividly and clearly could exist.

Imagination is different from pure understanding. Being able to imagine isn’t essential to me, as being able to understand is. Even if I had no power of imagination I would still be the same individual that I am, which seems to imply that my power of imagining depends on something other than myself. If there is such thing as my body, then it might be this very body that enables me to imagine corporeal things. But this is only a possibility, I still can’t see how, on the basis of the idea of corporeal nature, to prove for sure that some body exists.

I want to know if sensory perception provide me with any argument for the existence of bodies. To do that , I will (1). go back over the reasons for everything that I originally took to be perceived by the senses, and reckoned to be true. Next, (2). I will set out my reasons for later doubting these things. Finally, (3). I will consider what I should now believe about them.

(1). It seems impossible for the sensory ideas to come from within me, so I had to conclude that they came from external things. Also I remembered that I had the use of my senses before I ever had the use of reason, which convinced me that I had nothing at all in my intellect that I had not previously had in sensation. In addition, there is no connection between the tugging sensation and the decision to eat, it seems that nature taught me to make these judgments about objects of senses, for I was making them before I had any arguments to support them.

(2). Later on, my experiences undermined all my faith in the senses. Both external and internal senses can be mistaken. Also I decided the mere fact that the perceptions of the senses didn’t depend on my will was not enough to show that they came from outside me, for they might have been produced by some faculty of mine that I didn’t yet know.

(3). Now I don’t think I should recklessly accept everything that acquired from the senses, but I shouldn’t call it all into doubt either.

I have a vivid and clear idea of myself as something that thinks and isn’t extended, and a clear idea of body as something extended that does not think. So it is certain that I am really distinct from my body and can exist without it. Besides this I find that I am capable of imagination and sensory perception. And I see that I differ from my faculties as a thing differs from its properties. Sensory ideas are produced without my cooperation and often against my will, so there must be some substance other than myself that produces them. Since God would not be a deceiver, the senses must come from corporeal things instead of being transmitted from a source other than corporeal things, which means body exist.

My own nature teaches me that I have a body. Nature also teaches me that through these sensations of pain, hunger, that I am not merely in my body as a sailor is in a ship, rather, I am closely joined to it, so that it and I form a unit. The sensations are confused mental events that arise from the union - the intermingling of the mind with the body.

The right way to use the sensory perceptions that nature gives me is as a guide to what is beneficial or harmful for my mind-body complex. But it is a misuse of them to treat them as reliable guides to the essential nature of the bodies located outside me, for on that topic they give only very obscure and confused information.

The exaggerated doubts of the last few days should be dismissed as laughable. This applies especially to the chief reason for doubt, namely my inability to distinguish dreams from waking experience. For I now notice that the two are vastly different, in that dreams are never linked by memory with all the other actions of life as waking experiences are. And I ought not to have any doubt of its reality if that is unanimously confirmed by all my senses as well as my memory and intellect. From the fact that God isn’t a deceiver it follows that in cases like this I am completely free from error.

A similar summary of the book can be found in the previous notes on history of philosophy about Descartes as well.