Lecture 7.1 Descartes Meditation 2, 3.
TOPIC:
Descartes’ Rationalism; Wax argument; Argument for the Existence of God.
KEY TERMS/ GOALS:
Rationalism and Empiricism
“Cogito ergo sum.”
Wax argument.
Argument for the Existence of God.
READING:
Descartes. Meditations 2-3. Perry, p. 138-147.
CONTENT:
In the last lecture, we read about Descartes’ Foundationalism and Method of Doubt. Descartes argued that the
senses can deceive (we could be hallucinating, having visual illusions, or dreaming) so empirical evidence is not
foundational. Descartes also gave us a thought experiment to show that it is logically possible that a priori
knowledge can also be wrong, if there is an evil deceiver. He may have convinced that we can doubt just about
anything. We were convinced that any belief that we might have that comes to us from the senses is doubtable.
We came to even doubt whether we had a body or not. We also came to doubt that we could trust in a priori
beliefs like those we have about mathematics because of the evil demon or brain in the vat thought experiment.
If there is an evil deceiver, then it is (logically) possible that all our knowledge is false.
But if both a priori knowledge and empirical evidence is not foundational, then isn’t the skeptic right in saying
that there is NO foundational knowledge? How does Descartes solve this problem and answer against the
skeptic? What kind of knowledge is foundational? Descartes asks, “I suppose, then, that everything I see is
unreal. I believe that none of what my unreliable memory presents to me ever happened. I have no senses. Body,
shape, extension , motion, and place are fantasies. What then is true?” p. 138
COGITO, ERGO SUM.
Indeed, Descartes has lead us to a bleak place. Since we can doubt each kind of beliefs we have (empirical and a
priori) then it seems like the skeptic has won: We cannot justify our claims to knowledge.
But not so fast. He has a clever trick up his sleeve:
Here is a crucial passage from Mediation II. It appears Descartes has found a foundational belief.
"Well isn't it at least the case that I am something? But I now am denying that I have senses and a body.
But I stop here. For what follows from these denials? . . . Doesn't it follow that I don't exist? No; surely I
must exist if it's me who is convinced of something. But there is a deceiver, supremely powerful and
cunning, whose aim is to see that I am always deceived. Then surely I exist, since I am deceived. Let
him deceive me all he can, he will never make it the case that I am nothing while I think that I am
something. Thus having fully weighed every consideration, I must finally conclude the statement 'I am,
I exist' must be trued whenever I state or mentally consider it." p. 138.
Lecture 7.1 Descartes Meditation 2, 3.
What is Descartes saying here? What is the foundational belief that he finds? How does he argue for it?
In a little more detail, here’s how Descartes’ argument goes: If I am being deceived, then there must be
something (the I) that is being deceived. Therefore, I am a thing (a thinking thing) that is being deceived. His
argument is that even if he is being deceived, there MUST be something that is being deceived. What is that
thing? The thing that is being deceived. So, he must exist in order to be deceived.
Here is a famous passage that expresses the same idea:
"I noticed that while I was trying to think everything false, it must be that I, who was thinking this, was
something. And observing that this truth, I am thinking, therefore I exist [cogito ergo sum, in Latin], was so
solid and secure that the most extravagant suppositions of the skeptics could not overthrow it, I judged that I
need not scruple to accept it as the first principle of the philosophy I was seeking." (From Descartes' A Discourse
on Method).
The skeptic can try to convince Descartes that he does not KNOW (strictly speaking) whether the table or sun
exists, and he may not KNOW (without any doubt) mathematical or a priori knowledge. But the skeptic could
never convince Descartes that he does not exist.
The argument, basically, is that there is some thinking going on; there must be something to do that thinking;
therefore there is a thinking thing. Descartes' Argument has to be from the first person perspective. Saying “I
exist” is a truth for the person speaking. It is easy, that is, for US to doubt that Descartes is thinking. It is easy to
doubt that any other people are thinking. They might all be robots. But it is not for me to doubt that I am
thinking.
I might think that I am sitting here writing a lecture, but the evil deceiver could be deceiving me about that.
Keep in mind that we have not gotten rid of the Evil Demon possibility yet. The evil demon is always lurking in
the background and we are not entitled to believe anything that he might deceive us about. However, the fact
that I am thinking that I am writing a lecture is something I cannot doubt. To see this, consider that there is a
distinction between the content of thoughts (which can be doubted), and the act of thinking (that cannot be
doubted).Take, for example, the propositions, “I am writing a lecture,” and “It seems to me, or appears to me,
that I am writing a lecture.” I can doubt the first proposition. As I said, the evil demon could be deceiving me
about that. But I cannot doubt that it seems to me that I am writing a lecture. I can doubt that this desk is
brown, but I cannot doubt that it seems brown to me. So as Descartes says, the evil demon can deceive as much
as he likes, but he cannot deceive me when I think that I exist. If the demon is deceiving, then he is deceiving
someone, me. His argument, then, is:
P. I think
C. Therefore, I am.
He concludes that he exists (or at least his mind exists), since he can think about whether he is being deceived or
not. Do you think this is a good argument?
So what have we established about the sort of thing we are. We can't be sure that we have a body, but we can be
sure that we are a thinking thing. Descartes says, "But what then am I? A thinking thing. And what is that?
Something that doubts, understands, affirms, denies, wills, refuses--and also imagines and senses." - p. 140 So for
Descartes, your body is not essential to what you are, it is your mind or soul: The thinking thing, the cogito. We
will see in his 6th meditation that Descartes think mind and body are separable because we can doubt the
Lecture 7.1 Descartes Meditation 2, 3.
existence of our body, but we can't doubt the existence of our mind. (He is a dualist, as we shall see when we
read his meditation in the Philosophy of Mind section of this class). It is important to note that Descartes
privileges the thinking, rational part of the mind. Indeed, it is what makes humans uniquely human (Descartes
believes that no other animal thinks or is rational or is self-conscious). His focus on our rational faculties is one
indication that Descartes a Rationalist. Recall, that Rationalists think that SOME knowledge comes from pure
reason alone. The proposition “I think, therefore I am” is an a priori argument: He did not look at himself (in the
mirror, say) to gain empirical evidence that he exists (an evil demon could fool him about that). Rather, he
reasons that he must exist if he were being deceived. The first, foundational indubitable piece of knowledge is
this: “I think, therefore I am.”
THE WAX ARGUMENT
Now that we have one foundational bit of knowledge, maybe we can build off that foundation and gain other
knowledge that is certain and without doubts.
Carefully read p. 140 (second column) to 141 (to the end of Meditation 2). This passage is known as Descartes’
Wax argument. Identify the conclusion first (found on p. 141 last paragraph), and then go back and outline each
premise. Do this before you read the following, which is a simplified version of the common outline for the
argument.
The aim of the Wax argument is to establish that the mind or pure reason, which gives us a priori beliefs, is the
best source of knowledge. You can also read the argument as another critique of the senses as a source of
knowledge, since our senses deceive us about the true nature of the wax.
First, Descartes asks us to imagine that we just taken a piece of wax from a beehive. It has the sweet taste of
honey, it smells flowery, it has a specific shape, it feels hard and cool. In short we get information about the wax
from all five senses. We think, then, that our senses apparently can tell us everything there is to know about the
wax.
But then Descartes asks us to imagine now moving the piece of wax close to the fire. It melts. Now it is not cool,
but warm. It is not solid, but liquid. It no longer has a sweet taste. It loses the scent of flowers. We gain
information from the senses that at one moment it is hard and cold; tastes like honey; smells flowery; has specific
shape. But at the next moment, when the wax is heated, it loses all the properties that our senses told us it has. It
looks as though our senses have not told us the true nature of the wax. If we rely on our senses we can only
apparently know everything there is to know about a piece of wax. But from moment to moment (when the wax
is heated) it loses all the properties that our senses told us it has.
Nevertheless, we know it is the same piece of wax. We have an idea that wax is "something extended, flexible and
subject to change,” but that it’s nature does not change, only it’s properties change. We have ideas about the wax
that we gained not just from our senses, but from reasoning about the nature of wax. We come to understand
the nature of the wax using the perceptions of our mind, not the senses. The senses mislead us into thinking that
the essence of the wax was to have certain properties that in fact could change. It is by using our mind that we
discern that the wax is extended for example. Extension is “the property of taking up space.” We know that the
wax is extended, even though our senses simply give us changing sensory experiences from moment to moment.
At one moment, we see that the wax has a shape and is hard, but the next moment it is soft and liquid. We do
not see extension. Rather, extension is an abstract notion that our senses can't see. Our senses can give us
examples of specific things that are extended, but we cannot see an abstraction. Only our mind can "perceive an
abstraction."
Lecture 7.1 Descartes Meditation 2, 3.
Here’s another example of what Descartes has in mind. When someone says that they attend the University, if
you solely relied on your senses to tell you what a university is, then you would form images of this or that
building on campus. Without the ability from pure reason to abstract, then you would not understand that a
University is a whole system of people who work together to form a hierarchical structure of government, an
economic system, teachers and students, etc. Our senses only tell us about buildings and specific people. Other
examples of abstractions are the idea of “freedom,” “mammals,” “cats,” “fruits,” “cars,” etc. Each of these concepts
requires our reason to abstract from specific instances of mammals or fruits, to gain an idea of “mammals” and
“fruits” themselves.
Now, you might object you could generalize by finding what is similar amongst all extended things you perceive
with your senses. But Descartes argues that the act of “generalizing” is part of your pure reason. Indeed, he
argues elsewhere, you wouldn't know what feature to pick as being similar if you didn't already know what you
were looking for. Consider the image below:
Descartes might imagine that this is what our senses would show us about the world around us, without the
ability to reason. Reason gives us the ability to categorize, generalize, and even form concepts. Without concepts
are experience would be something like the picture above. How, then, could we tell which part is the extended
part? How would we know if there is a table in front of us, without the concept of “table”? Our senses would be a
continuing blur of visual and auditory and olfactory mess.
Back to the argument. How do I come to understand the true nature of the wax? By “inspection on the part of the
mind alone” (141). Only our Mind can perceive the true nature of the wax. Only by pure reason can we know that
the melted substance is the same thing as it was when it was solid. Only our minds tell us that the solid blob at
time 1 is the same thing as the messy liquid at time 2. Descartes thinks that since we can understand “extension”
“solidity” “wax” “liquid” and any number of concepts, that this fact tells us something about how our minds work.
In other words “Don’t I know myself much more truly and certainly, and also much more distinctly and plainly,
than I know the wax?” (141). He gains a “clear and distinct” idea of “extension” from looking at the wax, and
“extension” was a concept that was produced by his pure reason.
His argument, in short is that “physical objects are not really known through the sensation or imagination, but
are grasped by the understanding alone.” (141). His conclusion is that “I infer that I can’t know anything more
easily or plainly than my mind.” (141). The conclusion of the argument is to establish that the person (doing the
thinking) can perceive nothing more easily and evidently than his mind.
Lecture 7.1 Descartes Meditation 2, 3.
Here is Descartes’ Wax Argument:
P1. If we rely on our senses, we can apparently get to know all there is to know about a piece of wax.
P2. Our sense data shows us at one moment something that has color, shape an odor, etc.
P3. But at the next moment, we receive sense data of a hot, odorless liquid.
P4. But we KNOW that it is the same piece of wax.
P5. Our mind provided the information that it is the same piece of wax.
C: Nothing can be more easily and more evidently perceived by me than my mind.
Let me explain the conclusion a little more. I know what wax is by “inspection on the part of the mind alone.”
What this means is that we are confused when we say that we see the wax, because now we know that we
perceive it with our minds. (We don’t see WAX, we see various changing sense data). He says, “Nothing aids in
our perception of the wax that does not better demonstrate the nature of my mind” which means that all our
efforts to understand the nature of the wax allow us to understand the nature of how our minds work. If we have
a concept of extension, it is because our minds or reasoning faculties placed that category into our ideas as we
were sensing the blob of sensory images when we look at the changing wax.
RATIONALISM and EMPIRICISM.
The Wax argument is important because it highlights the privileged role that pure reason and rationality has.
Recall the distinction between Rationalists and Empiricists:
There are two main views about where our ideas come from:
Empiricism: all our ideas come from the senses. Empirical data is more foundational/ justified.
Rationalism: some of our ideas are innate and are not produced by any corresponding sensation. A priori
evidence is more foundational.
According to this definition, Descartes is a rationalist. You can see, from his Wax Argument, that most of the
things that we would claim to know (we know it is the same piece of wax, we know it has extension, we know it
is changing) originated from our reasoning faculties, not our senses.
At this point, you may have several objections, so be sure to share them on the discussion board. We will see that
David Hume (our Empiricist) will protest to some of Descartes premises.
DESCARTES ARGUMENT FOR THE EXISTENCE OF GOD (Meditation 3).
Descartes thinks that we can trust our knowledge that come from reason alone. In fact, he thinks that a priori
knowledge is more certain than information gained by the senses. He also thinks that we can trust our senses
most of the time. How does he argue for this? Remember we are still operating under the shadow of the evil
deceiver, so Descartes needs to give us reason to think that there is NOT an evil demon deceiving us, or that we
are NOT brains in a vat hooked up to super-intelligent computers.
Lecture 7.1 Descartes Meditation 2, 3.
Well, the argument is simple, and it may sound a bit cheap. After all, he spent a great deal of time trying to show
us why it is logically possible that we are being deceived, and should therefore doubt even a priori reasoning. But
alas, he leads us out of the shadow of doubt: If we can show that there is an all benevolent, all powerful, all
knowing God we get the extra premise we need, because an all benevolent God wouldn't never deceive us.
If God never deceives us, how do we account for illusions. Descartes idea is that God would not create us with
minds that leads us to false beliefs no matter how carefully we reason and no matter how much evidence we
consult. At the same time, it is obviously the case that we make mistakes. In Descartes view, God created us with
the CAPACITY to attain true beliefs about the world if we make good use of the minds he gave us.
So now we need an argument for God's existence. I’ll outline the argument first, and then explain the premises:
DESCARTES’ ARGUMENT FOR THE EXISTENCE OF GOD:
(1) I have an idea of God, infinity, all-knowing, etc.
(2) Everything has a cause.
(3) Like causes have like effects.
(4) Whatever created the concept of God must be equally powerful.
C: Therefore, God Exists.
Premise 1 is: “I have an idea of God.”
Descartes’ mind contains the idea of God. It is a CLEAR and DISTINCT idea, and the product of his REASON and
RATIONAL processes. Indeed the concept of God is an innate idea (it’s certainly not an empirical idea gained
from the senses). Therefore, it is a foundational and indubitable idea that can be trusted. Given that we have an
innate idea of God, Descartes thinks that we can infer things about the properties, and the source of that
concept. His concept of God (his CLEAR AND DISTINCT idea) reveals that God has these properties: God is an
eternal, infinite, omniscient, omnipotent being who is the creator of all things. This means that Descartes has an
idea of eternity, infinity, omniscience, omnipotence, etc.
Premise 2: Everything has a cause.
Of course every effect has a cause. So, what about the effect of his idea of eternity, infinity, omniscience, etc?
What were the causes of those ideas? How did Descartes come to have an idea of eternity?
Premise 3: Like effects have like causes.
In other words, every effect has to have a cause that is equal in power. If we see a broken window, we can ask
what or who caused it to break. The cause could be a brick, the person throwing the brick, or for a window in a
door, the wind slamming the door. So, the effect is the broken window and the cause is whatever we discover to
have been responsible for breaking the window. The cause and effect has to be similar in power. For example,
both the brick and the broken window are tangible things, they are made of physical substances, they are equally
hard, they are finite (not eternally existing), and so on. For Descartes, asking where his ideas (like his concept
of God) come from is an analogous question to our asking how the window was broken.
Lecture 7.1 Descartes Meditation 2, 3.
Premise 4: Whatever created the idea of God must be equally powerful.
Consider, now, what can possibly be the cause of the idea of ETERNITY, or INFINITY, or OMNICIENCE. Doesn’t
the cause have to be equally powerful, namely from a source that itself is eternal, infinite, and omniscient? His
idea of God includes the idea that God is an infinite being. Descartes does not think that the idea of infinity can
come from him, a being who is finite. He is thinking that since he has a clear and distinct idea of eternity or
infinity, that the source of that idea can only be caused by something that has those properties: Something that is
eternal and infinite itself.
Conclusion: God must exist.
God is the only thing that can create the idea of God. Nothing else is powerful enough to create the idea of
eternity, infinity, omniscience, omnipotence, etc.
Descartes argument has similarities to Aquinas' first cause argument and Anselm's ontological argument. He
starts from an empirical fact (his idea of God), and reasons that something must have caused the idea. He
concludes that only something as powerful as God could give him that idea. Here’s an example that might make
this idea more plausible: Consider that our idea of a table is created by real tables out there. Both the idea and
the real table have similar properties: they both represent solid planes with four or so legs. Our idea of infinite
numbers, too, must be caused by numbers which must, in fact, be infinite. How else could we have an idea that
numbers are infinite if they were not in fact infinite?
Descartes thinks that this argument shows us that God's existence is indubitable and hence God's existence is
another foundational belief we can work with. We can know that premise 1 is true by introspection, and we have
already shown that we cannot doubt the contents of our own mind.
Just as a criticism, we can press the soundness of some premises. Descartes takes premise two and three to be
obviously true as well. But you can ask, Are these two premises obviously true? Let’s examine Premise 3: Like
causes have like effects. If I pull a card out of bottom of a house of cards, what is the effect? Is that effect
anything like the cause? It’s not obvious to me that it is. An atomic bomb is created by splitting an atom,
something very very small. Yet its effect is huge—massive destruction.
Remember, Descartes is trying to dispose of the demon here. Each of these premises must be indubitable in the
way the fact that “I think therefore I am” is indubitable. This argument is crucial to Descartes project. Without a
proof of God's existence, the foundation of his epistemology will not be firm enough. With the argument for
God, he can now say that since God is benevolent, He would not allow us to exist in a world that was controlled
by an evil demon. So, we can be sure that we are not being deceived by the Evil Demon, and we are not brains in
the vat, and we are not living in a Matrix.
ASSESSMENT:
Be able to summarize Descartes’ Wax Argument, and his Argument for the Existence of God. Each argument
summary should be a good-sized paragraph. I will ask you to summarize these arguments on the Exam, so
prepare your paragraph now so that you can review it later. Do not skip any premises or steps, and come up with
your own examples to explain each premise.
DISCUSSION QUESTIONS:
Lecture 7.1 Descartes Meditation 2, 3.
Which kinds of beliefs/ ideas do you think are foundational: Ideas that come from the reason alone, or ideas that
come from the senses. Are you convinced by Descartes’ Wax Argument, that examining wax (or anything at all
for that matter) offers a window into how your mind works? Do you think that the concepts of “extension,” or
any other abstract category comes from your rational faculties alone? Are these concepts innate?
How could an empiricist argue that we could know the nature of wax by the senses alone?
Do you think Descartes’ argument for God’s existence is sound enough to conclude that we are not being
deceived by an Evil Demon?
As with any argument, you can critique them by asking if they are valid, sound, if there are unstated
assumptions, if they lead to absurd consequences, or if they contain informal fallacies. Critique Descartes’ Wax
argument and his argument for God’s existence. Be sure to discuss your critiques on the Discussion Board.