Descartes Wax

This blog is based on Meditation Two of Descartes Meditations on First Philosophy. This will deal specifically with Descartes analogy, or problem, with this pesky piece of wax of his.

“Let us consider the things which people commonly think they understand most distinctly of all; that is, the bodies which we touch and see. I do not mean bodies in general- for general perceptions are apt to be somewhat more confused- but one particular body. Let us take, for example, this piece of wax. It has just been taken from the honeycomb; it has not yet quite lost the taste of honey; it retains some of the scent of the flowers from which it as gathered; its colour, shape and size are plain to see; it is hard, cold and can be handled without difficulty; if you rap it with your knuckle it makes a sound. In short, it has everything which appears necessary to enable a body to be known as distinctly as possible. But even as I speak, I put the wax by the fire, and look: the residual taste is eliminated, the smell goes away, the colour changes, the shape is lost, the size increases; it becomes liquid and hot; you can hardly touch it, and if yous trike it, it no longer makes a sound. But does the same wax remain? It must be admitted that it does; no one denies it, no one thinks otherwise. So what was it in the wax that I understood with such distinctness? Evidently none of the features which I arrived at by means of the senses; for whatever came under states, smell, sight, touch or hearing has now altered- yet the wax remains.”

[As a side note, there was, supposedly, an auction of some of Descartes personal belonging. Some philosophers wanted to buy Descartes’ wax that is mentioned in this passage. And what was said was that it was a foot in height, and had been molded into a hat.]

So what is going on here in this passage? Descarte is going over what his senses presented to him, which happens to be this piece of wax. Now what is this wax that he knows by his senses? This is a particular body, as Descartes says. It has the property of  “tast[ing] of honey…the scent of the flowers…colour, shape and size…hard, cold and…handled without difficulty…it makes a sound.” All these things that were just listed “appears necessary to enable a body to be known as distinctly as possible.”Not only are these properties necessary to know them as distinctly as possible, it’s how we come to know of this body he calls wax. Remember, Descartes says “Let us consider the things which people commonly think they understand most distinctly of all; that is, the bodies which we touch and see. I do not mean bodies in general… but one particular body.”

He thinks that people typically think they understand, distinctly, bodies that they touch and see. He lists some of these properties that we think we understand, distinctly. We have one thing with all of these properties. Now he does something interesting, which is to put the piece of wax in a fire and pull it out. What do we notice about this thing that we thought we understood distinctly? Now the “taste is eliminated, the smell goes away, the colour changes, the shape is lost, the size increases; it becomes liquid and hot; you can hardly touch it, and if you strike it, it no longer makes a sound.” In other words, the piece of wax that we originally had is all of a sudden different. It no longer holds the properties that it just had, it changed. One and the same thing can be different at times.

Descartes comes to ask “[b]ut does the same wax remain?”. We notice the qualities change through time, but is there something that contains these qualities that remains through these changes in properties present to our senses?He says, ” It must be admitted that it does; no one denies it, no one thinks otherwise.” Now we seem to be in a predicament. We hold that something changes through time, yet remains the same in some sense, and that we don’t come to know of this thing from what our senses present to us. Either we have to give up the idea of things beneath what the senses present or there is something beneath what the senses present. He obviously decides to go with things beneath what the senses present. He is basically saying that experience doesn’t show us what lies beneath the appearances of the senses. He comes to ask and say,  “So what was it in the wax that I understood with such distinctness? Evidently none of the features which I arrived at by means of the senses.” This means we come up with the idea of “bodies” not through the senses, because the senses change when the bodies don’t really change, but through some other source than the senses.

“Perhaps the answer lies in the thought which now comes to my mind; namely, the wax was not after all the sweetness of the honey, or the fragrance of the flowers, or the whiteness, or shape, or the sound, but was rather a body which presented itself to me in these varies forms a little while ago, but which now exhibits different ones. But what exactly is it that I am now imagining? Let us concentrate, take away everything which does not belong to the wax, and see what is left: merely something extended, flexible and changeable. But what is meant here by ‘flexible’ and ‘changeable’? Is it what I picture in my imagination: that this piece of wax is capable of changing from a round shape to a square shape, or from a square shape to a triangular shape? Not at all; for I can grasp that the wax is capable of countless changes of this kind, yet I am unable to run through this immeasurable number of changes in my imagination, form which it follows that it is not the faculty of imagination that gives me my grasp of the wax as flexible and changeable. And what is meant by ‘extended’? Is the extension of the wax also unknown? For it increases if the wax melts, increases again if it boils, and is greater still of the heat is increased. I would not be making a correct judgement about the nature of wax unless I believed it capable of being extended in many more different ways than I will ever encompass in my imagination, I must therefore admit that the nature of this piece of wax is in no way revealed by my imagination, but is perceived by the mind alone. (I am speaking of this particular piece of wax; the point is even clearer with regard to wax in general.) But what is this wax which is perceived by the mind alone? It is of course the same wax which I see, which I touch, which I picture in my imagination, in short the same wax which I thought it to be from the start. And yet, and here is the point, the perception I have of it is a case not of vision or touch or imagination- nor has it ever been, despite previous appearances- but of purely mental scrutiny; and this can be imperfect and confused, as it was before, or clear and distinct as it is now, depending on how carefully I concentrate on what the wax consists in.”

He breaks down the piece of wax even further. He used his senses and found that the idea of the wax, this thing that is the wax, wasn’t derived from the senses. He now decides to change what else, besides these other qualities he listed before, made up this wax. He comes to find that it is based on being changeable, flexible, and extended. Now he wants to see if he derived these three main characteristics of the wax, since he discarded the senses because they don’t indicate anything to support the idea of the particular body of wax. Maybe it being changeable, flexible, and extended, can indicate anything to support the particular body of wax.

He comes to question what is meant by ‘changeable’ and ‘flexible’, because these are now the three things helps us come to the idea of this particular body known as wax. He doesn’t come to this idea based on his imagination, because he finds that there are many ways he can change or it flex it so that it takes different shapes. Yet his imagination is limited and could be changed even further than he can imagine. Thus, it doesn’t come through is imagination that he comes to the idea of this wax as changeable and flexible, nor through his senses since he just got rid of them previously.As he says, ” I am unable to run through this immeasurable number of changes in my imagination, form which it follows that it is not the faculty of imagination that gives me my grasp of the wax as flexible and changeable.”

He comes to question what is meant by ‘extension’, since this is the third idea of this particular body known as wax. He comes to think that ‘extension’ does not even help him come to the idea of this body known as wax, the particular one he has before him. He has seen the extension of the object change as well. For example, he has seen it melt and decrease, he has seen it boiled and it increases, and the extension goes even further when heated. He comes on to say, “I would not be making a correct judgement about the nature of wax unless I believed it capable of being extended in many more different ways than I will ever encompass in my imagination…” he eventually comes to say that his imagination does not give him the idea of this extension which he said was part of the three things that make up this particular body he knows as the wax. It was also not given to him by his senses.

His final conclusion comes down to, “I must therefore admit that the nature of this piece of wax is in no way revealed by my imagination, but is perceived by the mind alone. (I am speaking of this particular piece of wax; the point is even clearer with regard to wax in general.)” The conclusion is that the body of wax is something that we don’t derive from our senses or imagination. His conclusion is that ” the bodies which we touch and see…[have] none of the features  arrived at by means of the senses…[or] is in no way revealed by my imagination.” The imagination and senses don’t allow us to comprehend this thing that lies beneath what is present to our senses or imagination, but that we come to know of them through “mental scrutiny”, as Descartes says.

“But as I reach this conclusion I am amazed at how to error my mind is. For although I am thinking about these matters within myself, silently and without speaking, nonetheless the actual words bring me up short, and I am almost tricked by ordinary ways of talking. We say that we see the wax itself, if it is there before us, not that we judge it to be there from its colour or shape; and this might lead me to conclude without more ado that knowledge of the wax comes from what the eye sees, and not from the scrutiny of the mind alone. But then if I look out of the window and see men crossing the square, as I just happen to have done, I normally say that I see the men themselves, just as I say that I see the wax. Yet do I see any more than hats and coats which could conceal automatons? I judge that they are men. And so something which I thought I was seeing with my eyes is in fact grasped solely by the faculty of judgement which is in my mind.”

Descartes comes to point out that we are often lead to error by trusting what the senses and imagination present to us. This is because we believe that there is something that holds to all these qualities that we experienced with the senses. We also think that it also holds these other qualities of changeable, flexible, and extension. However, through mental scrutiny of this particular object of wax, he finds that he comes to no idea of a body beneath all of these qualities. But we have this idea of it, and he finds that we come to this conclusion based on “mental scrutiny”, which he also calls “Innate Ideas”.

He thought, as was previously pointed out, that there are some perplexing, if not out right contradictions, in holding to this idea of body based on the imagination and senses. Thus, to have this idea, it is not derived from the senses or imagination. But when we talk about these things, in our ordinary language, we come to think that there is something beneath what we experience, and that we come to know of it through the senses and imagination. We are “tricked” into ordinary ways of talking to hold this view. As he says, “We say that we see the wax itself, if it is there before us, not that we judge it to be there from its colour or shape; and this might lead me to conclude without more ado that knowledge of the wax comes from what the eye sees, and not from the scrutiny of the mind alone.”

Descartes comes to conclude that we judge there to that particular piece of wax with those properties because of the senses and imagination. He concludes that these people are wrong, if we hold to belief of some particular body known through senses and imagination. They ignore that we come to know of it through mental scrutiny, because neither the senses or imagination give us this idea. He also brings this up nicely through the example of the people he sees walking in the street. This is a clear example of the problem of other minds. The senses and imagination don’t give him the idea that there are people there, he judges them to be people and not automatons. He knows this through “Innate Ideas”, like he does about something being the body of particular wax, even though not know through senses or imaginations.

Review:

We believe there is a particular body, which is expressed by this wax Descartes has in his hand. The wax is expressed with taste, scent, color, shape, size, hard, cold, and makes sounds, by the human senses. He finds that these things change, they exist at one time and cease to exist at another. So don’t come to the idea of particular body, as expressed by this wax, through the human senses. The wax is expressed with ‘extension’, ‘changeable’, and ‘flexible’, by the imagination. He finds that these things change, and come and go as well. So don’t come to the idea of a particular body, as expressed by this wax, through the human imagination. But we believe that there is some particular body, and it doesn’t come from the senses or imagination. Thus, Descartes comes to say that we come to know of a particular body because of “mental scrutiny”.

There is someone who holds a different position than Descartes, drastically different, and that is George Berkeley. Descartes has his piece of wax and Berkeley has his apple.

Cartesian Circle

This blog will be based on an article by Lynn E. Ross, which was called “Cartesian Circle”. It appeared in a philosophical journal called Philosophy and Phenomenological Research, Vol. 26, No. 1 (Sep., 1965), pp. 80-89.

Ross brings up what is said to be the Cartesian Circle.

“Descartes’ reasoning is often said to be circular, in that he deduces the existence of God from clear and distinct perceptions and then deduces the reliability of our clear and distinct perceptions from the existence of God.”

Now Ross is going to try to show that when Descartes uses Clear and Distinct perceptions to prove the existence of God is true, but there is a difference. Descartes is not assuming the reliability of all clear and distinct perceptions. Descartes only presupposes the the reliability of Clear and Distinct perceptions that are known through the “light of nature”, through “metaphysical certainty” and not subject to “metaphysical doubt”.

Now what is a psychological certainty when it comes to a certain proposition?

“[W]e cannot conceive of its being false except on the rather extravagant supposition that even when we perceive it as true we are being deceived by some very powerful demon.”

Now what is something that we can call epistemological certainty?

“Those clear and distinct perceptions that we cannot be conceived to be false even on this demon hypothesis”

Psychological certainty isn’t metaphysical certainty. Psychological certainty is suspect to metaphysical doubt. Epistemological certainty isn’t metaphysical doubt. Epistemological certainty is based on metaphysical certainty, which comes from a faculty of the mind known as “light of nature” or “natural light”. We now have two levels or certainty.

These two levels of certainty have a corresponding of two levels of doubt.

[1.] There is metaphysical doubt, which is a proposition being conceived to be false on the demon hypothesis, and can be conceived to be false even without the demon hypothesis. For example, we can think that there is a world of corporeal things, like a chair, that exists independent of the person. This is called under question by the demon-hypothesis. But, we can also call into doubt something like I went to the grocery store yesterday, which we don’t need the demon-hypothesis to call into question because we are not even psychologically certain.  So metaphysical doubt is brought up when something can be false under the demon-hypothesis, which is something that is psychologically certain, or called false even when we ignore the demon-hypothesis and aren’t psychologically certain about it.

[2.] There is metaphysical certainty, which is a proposition that can’t be conceived of being false, even under the demon hypothesis (metaphysical doubt). These positions are what are given to use through the “light of Nature”. We can come to know that we exist, and this is metaphysically certain. Not even the demon hypothesis could change our minds of this. Thus, it is metaphysically certain and also epistemologically certain. He also comes to hold that God is part of these beliefs that are metaphysically certain and so epistemologically certain.

One of the things about Descartes idea is that any system that has metaphysical certainty must be based on premises that are given to us through the light of nature, and this would mean that we would have to exclude things, no matter how psychologically certain we are of them, even if we take it to be extravagant that we would have to give them up because they’re not given by the light of nature.

One of the examples of a conclusion that Descartes comes to, through the light of nature, is the Cogito of “I think, therefore I exist”. For example, he goes on to say that “the natural light…has shown me that I am from the fact that I doubt…Then without doubt I exist also if he [the demon] deceives me, and let him deceive me as much as he will, he can never cause me to be nothing so long as I think that I am something.”

Descartes comes to find, through natural light, that he exists and this cannot be doubted. This not being able to be doubted, makes it both metaphysical certain and also epistemologically certain. Descartes also goes on point out the thinking being, Descartes, has within him the idea of God, which contains all God’s attributes that are known through the light of nature alone. He comes to this conclusion based on something else that natural light gives to him.

“Now it is manifest by the natural light that there must at least be as much reality in the efficient and total cause as in its effect…Thus the light of nature causes me to know clearly that the ideas in me are like pictures or images which can, in truth, easily fall short of the perfection of the objects from which they have been derived, but which can never contain anything greater or more perfect.”

Descartes comes to the conclusion that he exists, which is based on metaphysical certainty, which happens by the light of nature. He also comes to the conclusion that there must be as much reality in the efficient and total cause as in its effect. This is also known by natural light. He finds that many of his ideas can be formed from what exists already in himself, by the light of the axioms that the effect contains as much reality as the cause, except for one. Through a process of elimination, he finds that he can’t conceivably have formed from what already exists within himself, yet he has the idea of God who contains this ability.

Descartes says that “Because the light of nature makes it very clear that whoever knows something more perfect than himself cannot be the author of his being, because then he would have given himself all the perfections of which he had cognizance…”

From all of this, Metaphysical certainty shows that if he was created at some point in time, then he must have been created by God. Descartes says that “I see nothing in all that I have just said which by the light of nature is not manifest to anyone who desires to think attentively on the subject.”

But Descartes has to make one further point.

“But thought I assume that perhaps I have always existed just as I am at present, neither can I escape the force of this reasonings, and imagine that the conclusion to be drawn from this is, that I need not seek for any author of my existence…For…in order to be conserved in each moment in which it endures, a substance has need of the same power and action as would be necessary to produce and create it anew, supposing it did not exist, so that the light of nature shows us clearly that the distinction between creation and conservation is solely a distinction of the reason.”

These things help lead to his cosmological argument for the existence of God. These were all based on, what Descartes calls, “light of nature” or “natural light”. These things were said to be based on metaphysical certainty, or epistemological certainty.

Descartes also comes up with this ontological argument, and there is supposed to be a detailed account of the argument in his Fifth Meditation. This meditation compares God’s property of existence with properties possessed by numbers and geometrical figures. However, there is a difference between those of mathematics and that of God. The one of God is known through natural light, while that of mathematics isn’t. The reason is that Descartes evil-demon even called into question mathematics, like “angles of a triangle are equal to two right angles”. This was called into question by the evil-demon, even though the idea of triangles is psychologically certain.

“The reason for comparing the existence of God with various properties of mathematical entities is to explain how existence is inseparable from God’s nature. Descartes’ purpose is not to suggest that we have the same level of certainty about God’s properties and the properties of mathematical entities. The latter are among the things subjected to metaphysical doubt earlier in the Meditations; their reliability is shown only after it has first been shown that God exists. The properties of God, on the other hand, are known by the light of nature and are not subject to metaphysical doubt…It is inconceivable that God should not have the property of existence, just as it is inconceivable that a triangle should not have three sides. And yet the inconceivability is not exactly the same in the two cases. For we can suppose that triangles need not be three-sided and that we are being deceived into thinking that they must be three-sided. But we cannot be deceived with respect to what we know through the light of nature, such as that existence is necessarily a property of God.”

What is being brought up here is that Descartes does not exclude the possibility of the existence of God being known with greater certainty than those attributes of mathematics. The latter are known through psychological certainty, and the former are known through the light of nature, which is metaphysical certainty.

So Ross comes to conclude that “for Descartes the ontological argument rests only on premises which are given by the light of nature. This means, since it is impossible for him to doubt or in any way pretend that the things known by the light of nature are false, that the ontological argument is metaphysically certain, and that it is therefore equivalent to the cosmological argument in certainty.”

Descartes also once said that “it is incumbent on us to imagine that he is a deceiver if we wish to cast doubt upon our clear and distinct perceptions.” Ross suggests that “no contrary reason” could cast doubt upon the truth of clear and distinct perceptions is that “they were only open to metaphysical doubt under the demon hypothesis”. However, now that Descartes has reached God, he can now say that all clear and distinct perceptions are true.

What happens is this: Some clear and distinct perceptions are metaphysically certain even with the Demon hypothesis. Some clear and distinct perceptions are metaphysically doubtful with the Demon hypothesis. Those clear and distinct perceptions that are metaphysically certain, with the Demon hypothesis, allow us to combine them to each other to reach the existence of God. Applying metaphysically certain ideas only leads to other metaphysically certain ideas, which becomes that of the existence of God. And this is known by natural light, and also that God is no deceiver. Now those clear and distinct things that could be doubted under the Demon hypothesis can no longer be doubted, because God has banished this demon away by God’s very existence, and this leads to all clear and distinct perceptions are metaphysically certain. In other words, those that clear and distinct perceptions that were in metaphysical doubt, turn out to be metaphysically certain once it is found that there is no deceiver.

Descartes makes a reply to an alleged circularity with is Clear and Distinct idea and God.

“…when I said that we could know nothing with certainty unless we were first aware that God existed, I announced in express terms that I referred only to the science apprehending such conclusions as can recur in memory without attending further to the proofs which led me to make them. Further, knowledge of first principles is not usually called science by dialecticians. But when we become aware that we are thinking beings, this is a primitive act of knowledge derived from no syllogistic reasonings. He who says, ‘I think, hence I am, or exist’, does not deduce existence form thought by syllogism, but, by a simple act of mental vision, recognizes it as if it were a thing that is known per se.”

Ross comes to a conclusion like this, based on what has been said before.

“[Descartes] is placing some limitation on the clear and distinct perceptions whose truth is first established after the existence of God is proved. Not all clear and distinct perceptions depend upon our knowing that there is a God, but only those that are in some unspecified conclusions of demonstrations, as opposed to the sort of first principles that one recognizes “by a simple act of mental vision…as if it were a thing that is known per se.” I take these first principles known per se to be metaphysically certain principles given by the light of nature, and I suggest that “such conclusions as can recur in memory without attending further to the proofs which led me to make them” is his way of referring to those clear and distinct perceptions not given by the light of nature. For in metaphysics the light of nature provides the only perceptions whose truth is completely and independently certain and need to be demonstrated. And the truth of the of the remaining clear and distinct perceptions, since they are subject to the demon hypothesis and to metaphysical doubt, needs to be demonstrated from the existence of a benevolent God. We are metaphysically certain that they are true only so long as we remember that their truth was metaphysically demonstrated from first principles known per se. When we do not remember this demonstration (which involves the demonstration of the existence of a God who would not deceive us with respect to our clear and distinct perceptions), these clear and distinct perceptions are once more subject to the demon hypothesis and thus lack metaphysical certainty. If this is Descartes’ meaning, he is clearly justified in rejecting the charge of circularity.”

Ross, in concluding the paper, makes a certain point. He finds that Descartes can escape the charge of circularity, but Ross things that there is another possible problem, as he has interpreted Descartes. He points out that he has not really shown that some of his other metaphysically certain positions, besides his “questionable” “I think, therefore I exist”, withstand the Demon hypothesis. Ross, in fact, goes on to think that his other metaphysically certain premises even fall to the demon hypothesis, which would make them metaphysically doubtful. Ross says this because Descartes usually produces this claim of a certain proposition being known by the “light of nature”, and never really offers any argument to support these metaphysically certain positions that he knows by the “light of nature”.

As Ross says, “from then on (after getting the cogito ergo sum principle) he smuggles in one crucial premise after another without ever attempting to establish the metaphysical certainty of even one. The result is that his metaphysics is based upon a great many premises whose “metaphysical certainty” is at best highly questionable, and at worst non-existent. This, rather than circularity, is the basic flaw in Descartes’ work.” I, myself, might add one thing in this regard. Descartes held that we have some innate ideas, and so these innate ideas would appear to be what is known by “light of nature”. So he doesn’t, in some sense, have to defend these premises that are known by the “light of nature”. This would be consistent with his whole system. So one can question these innate ideas if they want to attack his system.

Descartes and Skepticism

This blog will be based on Renee Descartes and his writing of his Meditations on First Philosophy. I will be quoting some portions of his Meditations, which deals with some skeptical arguments or conclusions.

Descartes comes up with a certain quote to show how we can be lead to skepticism. He states, “Once the foundations of a building are undermined, anything built on them collapses of its own accord.” Now he tries to present three types of arguments, in the First Meditation, that would be good enough to collapse the foundation upon which we build up our knowledge.

Argument from Illusion

“Whatever I have up till now accepted as most rue I have acquired either from the senses or through the senses. But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once.”

One thing to take notice of is when he says “either from the senses or through the senses”. Now the portion that says “from the senses” I take to be obvious, but it is the second part of “through the senses” that could be a little tougher. Now when I watch the news on TV, I have the sensory information of someone sitting behind a desk, and I hear words. These words are taken through the senses, and it could be something like “The Boston Celtics beat the New York Knicks in overtime”. That is information through the senses. Or, take the example of someone you know who went to another country and told you what they experienced in another country. That is information through your senses, even though you never experienced it with your own senses.

Argument from Dream

“How often, asleep at night, am I convinced of just such familiar events-that I am here in my dressing-gown, sitting by the fire- when in fact I am lying undressed in bed! yet at the moment my eyes are certainly wide awake when I look at this piece of paper; I shake my head and it is not asleep; as I stretch out and feel my hand I do so deliberately, and I know what I am doing. All this would not happen with such distinctness to someone asleep. Indeed! As if I did not remember other occasions when I have been tricked by exactly similar thoughts while asleep! As I think about this more carefully, I see plainly that there are never any sure signs by means of which being awake can be distinguished from being asleep. The result is that I being to feel dazed, and this very feeling only reinforces the notion that I may be asleep.”

Argument from Evil-Demon

“And yet firmly rooted in my mind is the long-standing belief that there is an omnipotent God who made me the kind of creature that I am. How do I know that he has not brought it about that there is no earth, no sky, no extended thing, no shape, no size, no place, while at the same time ensuring that all these things appear to me to exit just as they do now? Moreover, since I sometimes consider that others go astray in cases where they think they have the most perfect knowledge, may I not similarly go wrong every time I add two and three or count the sides of a square, or in some even simpler matter, if that is imaginable?…I will suppose therefore that not God, who is supremely good and the source of truth, but rather 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, colors, shapes, sounds and all external things are merely the delusions of dreams which he has devised to ensnare my judgement. I shall consider myself as not having hands or eyes, or flesh, or blood or senses, but as falsely believing that I have all these things…I am like a prisoner who is enjoying an imaginary freedom while asleep; as he begins to suspect that he is asleep, he dreads being woken up, and goes along with the pleasant illusion as long as he can.”

Now after he has gone through these three skeptical arguments, he comes to a certain conclusion, even based on that of the evil-demon.

“But I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I too do not exist? No: if I convinced myself of something then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case I too undoubtedly exist, if he is deceiving me; and let him device me as much as he can, he will never bring ti about that I am nothing so long as I think that I am something. So after considering everything very thoroughly, I must finally conclude that this proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.”

Descartes points out that even if there is an evil-demon, or it’s all a dream, or it’s all an illusion, it is still something that is being deceived. This can’t be doubted that something is being doubted. To be deceived is for something to be deceived.

“I am a thing that thinks: that is, a thing that doubts, affirms, denies, understands a few things, is ignorant of many things, is willing, is unwilling, and also which imagines and has sensory perceptions; for as I have noted before, even though the objects of my sensory experience and imagination may have no existence outside of me, nonetheless the modes of thinking which I refer to as cases of sensory perceptions and imagination, in so far as they are simply modes of thinking, do exist with in me- of that I am certain…I am certain that I am a thinking thing.”

Now I need to point out one thing, which was that Descartes was one of the first philosophers, and other modern philosophers like John Locke and George Berkeley were to follow, would use the word “Idea” to mean his sense-perceptions.

“Yet I previously accepted as wholly certain and evident many things which I afterwards realized were doubtful. What were these? The earth, sky, stars, and everything else that I apprehended with the senses. But what was it about them that I perceived clearly? Just that the ideas (i.e. sense-perception), or thoughts, of such things appeared before my mind. Yet even now I am not denying that these ideas occur within me. But there was something else which I used to assert, and which through habitual belief I thought I perceived clearly, although I did not in fact do so. this was that there were things outside of me which were the sources of my ideas (i.e. sense-perceptions) and which resembled them in all respects. Here was my mistake; or at any rate, if my judgement was true, it was not because of any knowledge I possessed.”

“Thus the only remaining thoughts where I must be on my guard against making a mistake are judgements. And the chief and most common mistake which is to be found here consists in my judging that the ideas which are in me resemble, or conform to, things located outside of me. Of course, if I considered just the ideas themselves simply as modes of my thought, without referring them to anything else, they could scarcely give me any material for error…But the chief question this point concerns the ideas which I take to be derived from things existing outside me: what is my reason for thinking that they resemble these things? Nature has apparently taught me to think this…When I say ‘Nature taught me to think this’, all I men is that a spontaneous impulse leads me to believe it, not that its truth has been revealed to me…”

“although these ideas(i.e. sense-perception) do not depend on my will, it does not follow that they must come from things located outside of me…there may be some other faculty not yet fully known to me, which produces these ideas without any assistance form external things; this is, after all, just how I have always thought ideas (i.e. sense-perception) are produced in me when I am dreaming. And finally, even if these ideas did come from things other than myself, it would not follow that they must resemble those things. Indeed, I think I have often discovered a great disparity between an object and its idea (i.e. sense-perception) in many cases. For example, there are two different ideas of the sun which I find within me. One of them , which is acquired as it were from the senses and which is a prime example of an idea which I reckon to come from an external source, makes the sun appear very small. the other idea is based on astronomical reasoning, that is, it is derived from certain notions which are innate to me (or else it is constructed by me in some other way), and this idea shows the sun to be several times larger than the earth….All these considers are enough to establish that its not reliable judgement but merely some blind impulse that has made me believe up till now that thee exists things distinct from myself which transmit to me ideas or images of themselves through the sense organs or in some other way.”

Problem of Other Minds

“if I look out of the window and see men crossing the square, as I just happen to have done, I normally say that I see the men themselves, just as I say that I see the wax. Yet do I see any more than hats and coats which could conceal automatons? I judge that they are men.”

All these quotes came from Descartes book, which I gave a link to, and are based on Meditation one, two, and three.