Description
—What is Parmenides’ conception of nature and reality? Does he think it is ultimately “one” or “many”? —Why does Parmenides need to travel both the Path of Truth and the Path of Seeming? Why can’t he just stop at the Path of Truth? —How do Heraclitus and Parmenides agree? How do they disagree? —What is the role of fire in Heraclitus’ philosophy? How does fire illustrate Heraclitus’ conception of change and identity in nature? —“Changing, it rests.” Explain this fragment from Heraclitus as best you can. (Hint: Fire “rests” and retains its identity through “changing” constantly.) —In the Allegory of the Cave, Socrates explains to Glaucon that reality is often not as it appears. Why are the shadows on the cave wall not fully “real”? —Plato thinks the Forms are the most real things in existence. The Forms, according to Plato, serve as the archetypes for everything we encounter. Describe some characteristics of the Forms. Are they material or immaterial? Are they eternal or temporary? Are they perfect or imperfect? Subjective or objective? —What is Aristotle’s “Third Man Argument”? How does this demonstrate Aristotle’s core disagreement with his teacher Plato? —Plato thought the most real things were also purely intelligible; that is, he thought they were pure form with zero material. Does Aristotle agree or disagree? If he disagrees, what does he think instead? —Explain a bronze statue in terms of Aristotle’s Four Causes. —Aristotle’s conception of the virtues relies heavily on habit and repetition. He says: “We are what we repeatedly do.” In order to live a virtuous life, we must aim for the Golden Mean. What is the Golden Mean? Give an example. —Descartes’ famous phrase, “I think, therefore I am,” is actually a shortened version of the complete phrase, “I doubt, therefore I think, therefore I am.” How is the second phrase different from the first? What is the importance of doubt for Descartes? —Describe the difference between methodological doubt and real doubt. —As soon as Descartes conceives of the possibility of an “evil deceiver,” mathematics loses its candidacy to be Descartes’ foundation for knowledge. This is despite mathematics being an a-priori type of knowledge. What is the difference between a-priori and a-posteriori? What is it about math that makes it a-priori?
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René Descartes’s Rationalism
Written by Ashton Trumble
Selected Portions of Meditations on First Philosophy Translated from Latin to English by
Ashton Trumble
In order to fully understand the epistemology (the theory of knowledge which seeks to
answer the question of ‘how do we know what we know?’) of René Descartes, we ought to first
review the epistemology of Plato. Indeed, though they are separated by many centuries,
Descartes and Plato are share several key similarities in their philosophical thought. You may
remember that, according to Plato, true knowledge requires a kind of transcendence of the
ever-changing flux of the material world. When we transcend this flux, we grasp—even though
temporarily—the permanent, rational order behind the changing physical realm. This reveals
that there exists an eternal, perfect “universal” archetype for every thing that exists; these
archetypes are the Forms. When we “know” a form—that is, when we recognize the
permanence behind the ever-changing physical world—we grasp on to something that is
completely rational. This “grasping” is an intellectual act of the mind, which, in its purest
manifestation, is exclusively formal (i.e. mathematical). Such an intellectual act can only take
place if there are certain innate ideas upon which it can be based. Knowing, then, is an act of
making the observable world intelligible by showing how it is related to an eternal order of
intelligible truths. These features of Plato’s epistemology are part of the program of
rationalism, one of the two key epistemological poles in Western thought.
Platonic rationalism was immediately countered by the philosophy of Plato’s student
Aristotle with what would eventually become known as empiricism. Yet rationalism managed to
dominate later Greek and Roman philosophy and all of the early Middle Ages, only to be
countered once again by a revival of Aristotelianism in the work of St. Thomas Aquinas in the
thirteenth century. But that’s a story for another time.
Rationalism achieved its fullest maturity in the seventeenth century in the work of René
Descartes (1596-1650). Before we inspect his version of rationalism, let us first take into
consideration the context in which it was created. As Alasdair MacIntyre rightly points out,
theories of knowledge are never created in a vacuum. There are always psychological,
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economic, social, and political conditions acting as motivations for them. In a certain sense each
epistemology, rather than describing and accounting for some autonomous thing called
“knowledge,” perhaps actually creates and validates its own “knowledge,” which is
circumscribed and limited by the contextual forces that motivated the epistemology in the first
place. The external circumstances that motivated Plato were very different from those that
motivated Descartes. Plato, a man of noble ancestry, lived at a time when the old aristocratic
system of governing was collapsing in the face of the emergence of a new commercial class and
an incipient democracy. In the two-hundred-year period before Plato’s time, social and
intellectual conditions had conspired to undermine the moral authority of the old aristocratic
values, whose canon was the myths of Homer and Hesiod. As the old values of honor, dignity,
loyalty, courage, and the natural right of the nobility to govern deteriorated, they were being
replaced with what to Plato were plebeian values that thinly disguised greed and the thirst for
power. These new values were taught in Socrates’ and Plato’s day by the professors of rhetoric
known as “the Sophists,” who, from the perspective of Socrates and Plato, seemed to celebrate
perversely a world in which language was used as a means to manipulate and gain power over
one’s conversation partner (as opposed to working together to discover the truth). In order to
counteract the Sophists’ corroding influence and to maintain some structure that justified rule
by an elite (remember the ‘Philosopher Kings’), Plato not only had to attack the Sophists, but he
also had to oppose the authority of Homer and replace it with the authority of Pure Reason.
The works of Homer had embodied the aristocratic values that Plato wished to support,
but Homer had offered no defense of those values except an appeal to the emotions through
his poetic discourse. If Plato was to defend these values rationally, he had to replace the power
of poetry (for the ancient Greeks, “poetry” manifested as epic myths, comedies and dramas)
with that of philosophy. The poetry/philosophy opposition is not the one that faced René
Descartes in the seventeenth century. Rather, he was confronted by the religion/science
opposition. Descartes lived during a period that birthed new sciences. For some perspective:
Copernicus had been dead only forty years when Descartes was born. Descartes was a
contemporary of Galileo and Kepler. Newton was eight years old when Descartes died. In fact,
Descartes himself had made a major contribution to the history of science while still in his
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twenties by discovering analytic geometry. (That totally doesn’t make me feel un-productive or
anything…)
Now the ever-increasing power of the new science was beginning to challenge the
waning authority of the Catholic Church, which had dominated for a thousand years but had
suffered several major setbacks in the two hundred years before Descartes’s birth (a series of
internal schisms, defeats at the hands of secular rulers, and the emergence of the Protestant
Reformation). The Church was fighting to retain not only what political power it still had but
also its custody over the human moral self-image. It was in this sphere that the new sciences
seemed to be most directly challenging religious authority, and the confrontation came to a
head in 1632, when the Inquisition arrested Galileo, tried him, and found him guilty of impiety.
The specific event that provoked Galileo’s arrest was the publication of an essay reporting his
discovery that there were four moons orbiting the planet Jupiter. Now, it may not be
immediately obvious why the religious authorities would be threatened by such a claim. The
traditional view of what was at stake in the Galileo affair is this: For a thousand years, the
concept of human dignity was closely bound to the idea that God had created the Garden of
Eden in the very center of the universe and that the rest of the cosmos was formed as a series
of concentric circles radiating out of Eden, the belly button of reality. This view meant that the
human drama was the key drama in the cosmos and that every other being in the universe was
simply placed here as a witness to the human drama. This concept had the effect of imbuing
every human act with meaning. Even if one’s life was filled with misery (and there was plenty of
misery in the medieval world), at least that misery had significance; hence there was a certain
dignity in even the most miserable human existence.
Now this heroic conception of human life was suddenly threatened by the Copernican
theory that the earth was not the center of the universe—that inf act the earth and the other
planets actually orbited the sun (that is, that the heliocentric and not the geocentric theory was
correct). If the earth is just hurtling through space with no more and no less meaning than that
of any other body in the universe, what would this finding mean for the concept of human
dignity? But there was one scientific fact that prevented the Copernican radicals from winning
the day. It was the undisputed fact that the earth’s moon orbits the earth. If the heliocentric
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theory were true, why would the moon orbit the earth? Why wouldn’t it travel around the sun
the same way the earth was supposed to do? Now you can see the significance of Galileo’s
discovery. If Jupiter’s moons orbit Jupiter, that then proves moons can orbit planets that are
not the center of the universe, and this proof kicked the last strut out from under the
geocentric theory.
Somewhat like Galileo, Descartes found himself in an awkward situation. He was a
dedicated Catholic who did not look forward to a confrontation with the ecclesiastical
authorities, yet he had just finished a manuscript on physics, many sections of which he knew
would agree with Galileo. So rather than publish his manuscript, he decided to write a book of
philosophy that would create an intellectual climate of reconciliation between science and
religion. He wanted to show that the idea of being a “religious scientist” was not selfcontradictory. He did this in his book Meditations on First Philosophy. And in my own opinion,
Descartes was successful in his undertaking. As far as I can determine, Catholicism never again
had a head-on confrontation with science to the degree that it did during the Enlightenment.
Descartes had demonstrated that this collision course was not necessary.
So then, let us turn to Descartes’s epistemology as he developed it in the Meditations.
(Descartes originally wrote this book in Latin. It has been translated a million different times in
a million different ways, some better than others. Each translation in this summary is my own.)
In the first paragraph, Descartes announces his proposal: “I must once and for all seriously
undertake to rid myself of all the opinions which I had formerly accepted and commence to
build anew from the foundation, if I wanted to establish any firm and permanent structure in
the sciences.” Notice a key metaphor in this passage, one taken from carpentry. Knowledge is
seen as a building in which all the superstructure is resting on a foundation, and the building is
only as strong as the foundation. He continues: “Inasmuch as reason already persuades me that
I ought no less carefully to withhold my assent from matters which are not entirely certain and
indubitable than from those which appear to me manifestly to be false, if I am able to find in
each one some reason to doubt, this will suffice to justify my rejecting the whole.” Here we see
Descartes’s technique, which has come to be known as methodological doubt. It has a motto:
De omnibus dubitandum est (Everything is to be doubted), and it requires Descartes to doubt
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any proposition whatsoever if he can find the slightest reason to do so. Notice that, unlike
courts of law, methodological doubt does not require that the doubt be reasonable; rather, any
possible doubt will be sufficient to put a proposition out of commission. And the point of all this
doubting is to attempt to find something that cannot be doubted, something indubitable,
absolutely certain. That absolute certainty, if it exists, will be the foundation of the house of
knowledge. Descartes writes:
“I shall proceed by setting aside all that which the least doubt could be supposed to
exist, just as if I had discovered that it was absolutely false; and I shall ever follow this road until
I have met with something which is certain, or at least, if I can do nothing else, until I have
learned for certain that there is nothing in the world that is certain.”
The point here is to discover the foundation of knowledge, if there is such a thing to be
discovered. And if there is no foundation to discover, then the methodology will be abandoned.
But this would result in much more cynicism than prior to attempting the methodology, since
this would imply that there is no such thing as true knowledge; only hearsay, opinions,
prejudices, and passions would exist. The “house of knowledge” would be built on shifting
sands. Descartes continues:
“All that up to the present time I have accepted as most true and certain I have learned
either from the senses or through the senses; but it is sometimes proved to me that these
senses are deceptive, and it is wiser not to trust entirely to anything by which we have once
been deceived.”
Here we see that Descartes’s dismantling of the rotten timbers from the house of
knowledge is done more with a bulldozer than a crowbar. Because the senses are known
deceivers, they will be doubted away, which means that all beliefs based on the senses (which,
after all, is most of them) will be jettisoned. But suddenly Descartes himself suspects that
perhaps his house bashing is moving too fast. He says:
“But it may be that although the senses sometimes deceive us concerning things which
are hardly perceptible, or very far away, there are yet many others to be met with as to which
we cannot reasonably have any doubt, although we recognize them by their means. For
example, there is the fact that I am here, seated by the fire, attired in a dressing gown, having
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this paper in my hands and other similar matters. And how should I deny that these hands and
this body are mine, were it not perhaps that I compare myself to certain persons, devoid of
sense, whose cerebella are so troubled and clouded by the violent vapors of black bile, that
they constantly assure us that they think they are kings when they are really quite poor, or that
they are clothed in purple when they are really without covering, or who imagine that they
have an earthenware head or are nothing but pumpkins or are made of glass. But they are mad,
and I should not be any less insane were I to follow examples so extravagant.”
So there is our boy René Descartes, sitting in his PJs alone at his desk in front of his
fireplace. (Quite a different stage from that of Socrates, who philosophized in the streets of
Athens, seeing philosophy as essentially a social activity! It is clear that the notion of thinking
has undergone a dramatic change since the Greek period.) Descartes stares at his hand and
thinks, “This is my hand.” How could he possibly be wrong? Only a madman could stare at his
hand and wonder if it is his hand. If, after leaving our classroom, you see someone sitting by the
second floor café staring at their hand, and the person says to you, “I’m not sure this is my
hand,” you won’t say to yourself, “A philosopher!” Rather, you’ll say, “Hah. Drugs.” Descartes
knows this perfectly well, yet, following the strictures of rational doubt, he does indeed
question whether what he is looking at is his hand. He continues:
“At the same time I must remember that…I am in the habit of sleeping, and in my
dreams representing to myself the same things or sometimes even less probable things than do
those who are insane in their waking moments. How often has it happened to me that in the
night I dreamt that I found myself in this particular place, that I was dressed and seated near
the fire, whilst in reality I was lying undressed in bed! I remind myself that on many occasions I
have in sleep been deceived by similar illusions, and in dwelling carefully on this reflection I see
so manifestly that there are no certain indications by which we may clearly distinguish
wakefulness from sleep that I am lost in astonishment.”
Do you get Descartes’s point? Can you refute him? Can you think of a test that will prove
you are not dreaming right now? Obviously, pinching yourself won’t work because it is quite
possible to dream that you are pinching yourself. For the same reason, you can’t just ask your
neighbor “Am I dreaming?” It is possible to dream whatever answer your neighbor gives. In
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fact, it seems that Descartes has us over a barrel because the only way to refute him would be
to think of a test that can’t be dreamed. But any test you can think of, you can dream.
Descartes’s conclusion is not that one should keep wondering whether or not one is
dreaming, but that there is no philosophical proof that at any given moment one is not
dreaming. Therefore the senses and the commonsense picture of the world based on the
senses cannot be the foundation of knowledge.
The real point Descartes is trying to make here is worth pausing over. It requires
reminding yourself of two technical philosophical terms that we have already briefly discussed
in class: a priori and a posteriori. An a priori claim is a claim whose truth or falsity can be known
independently of observation. An a posteriori claim is one whose truth or falsity can be known
only by appealing to observation. Now Descartes’s point can be put this way: the “argument
from illusions” and the “argument from dreams” can only attack a posteriori claims. But
mathematics is a priori, hence it should escape both of these skeptical arguments. One does
not prove that 2+3=5 by taking a field trip or doing an experiment. The way you prove that
2+3=5 is by demonstrating that this proposition is a version of the proposition A=A, and then
demonstrating that any denial that A=A leads to a self-contradiction. This kind of proof is not an
act of perception but is what Plato would call an act of “pure reason.”
So what Descartes is asking is whether the a priori truths of mathematics might not
serve as the absolutely certain foundations of knowledge. Descartes was a mathematician, after
all, so he would no doubt have loved to answer that question affirmatively, but the rigors of
methodological doubt forced him to answer in the negative, as we will see:
“Nevertheless I have long had fixed in my mind the belief that an all-powerful God
existed by whom I have been created such as I am. But how do I know that He has not brought
it to pass that there is no earth, no heaven, no extended body, no magnitude, no place, and
that nevertheless I possess the perceptions of all these things and that they seem to me to exist
just exactly as I now see them? And besides, as I sometimes imagine that others deceive
themselves in the things which they think they know best, how do I know that I am not
deceived every time that I add two and three, or count the sides of a square or judge of things
yet simpler, if anything simpler can be imagined?”
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This text is the introduction to one of the most curious chapters in the history of
philosophy: Descartes’s “evil genius” hypothesis. Descartes asks himself: How do I know that
the universe was not created by a malevolent demon whose only goal is to deceive so that even
when I make the most basic mathematical judgments, such as that 2+3=5, I err; yet I never
know that I am erring? Much to Descartes’s chagrin, he realizes that he cannot disprove the
existence of such a “god.” Therefore, even if it is not very likely that this being exists, its
existence is still logically possible, and from this it follows that mathematics is not absolutely
certain. Imagine a math teacher who has to tell their students, “Two plus three equals
five…unless there is an evil genius ruling over us all, in which case, two plus three may not equal
five.” If one has to add that qualification to math, then math is not unqualifiably true, and it
cannot be the foundation of knowledge.
So now Descartes needs some sort of foothold to help him climb out of the proverbial
abyss into which he has fallen. Well, then, is there a truth so certain that it can be known
indubitably even if the senses deceive Descartes, even if he is dreaming, and even if there is an
evil genius?
“I myself, am I not at least something? Without doubt I exist also if [the evil genius]
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. So that after having reflected well and carefully
examined all things, we must come to the definite conclusion that this proposition: I am, I exist,
is necessarily true each time that I pronounce it, or that I mentally conceive it.”
This, then, is the absolutely certain foundation of all knowledge. In the Meditations, the
version is, “I am.” In another work, Discourse on Method, the version is “I doubt, therefore I
think, therefore I am.” (Dubito, ergo cogito, ergo sum). This truth is certain under any possible
conditions. Every time I make the assertion “I am,” I am right. Not even an evil genius or
madness can falsify this finding. Descartes clarifies the nature of this finding:
“I do not now admit anything which is not necessarily true: to speak accurately I am not
more than a thing which thinks, that is to say a mind or a soul, or an understanding, or a
reason…I am, however, a real thing and really exist; but what thing? I have answered: a thing
which thinks.”
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So selfhood’s essence of which Descartes is so certain is thought or consciousness
(which, as you will see, Descartes conveniently equates with “soul.” Perhaps his Catholicism is
sticking out a bit here). This discussion introduces Descartes’s notorious mind-body dualism.
The self is defined as a mind or a soul (a “thing which thinks”), and the body is not an essential
part of the self. This is because although it is odd to doubt you have a body, it is not impossible
to doubt you have a body, and Descartes’s entire project is based on doubting everything that is
possible to doubt. The only thing that is not possible to doubt is the fact that you are doubting,
which means you have a mind, which means you are a thing which thinks, which means you
“are,” a.k.a. you exist. To Descartes, there is a necessary relation between selfhood and mind
and only a contingent (non-necessary) relation between self and body.
Now we are going to proceed with the construction of Descartes’s house of knowledge,
but we are going to speed things up quite a bit. Descartes knows that he is still operating in the
shadow of an evil genius and that before he can progress, he must dispose of this demon. There
is only one way to do this, according to Descartes, and that is to prove the existence of God.
This is because the concept of God as an all-knowing, all-powerful, and all-good creator of the
universe is logically incompatible with the concept of an evil genius. Either one of them could
exist but not both. So if Descartes can prove God’s existence, he will have disproved the
existence of an evil genius. Descartes’s proof will have to be strictly a priori because no
observation can be trusted. It will have to be absolutely certain and rest firmly on the
foundation of the “cogito,” the foundation of “I think therefore I am.” Perhaps the simplest
version of Descartes’s argument is based on the concept of perfection. Rather than quote it
directly, I will formalize it in a series of six steps.
1. A being that doubts is an imperfect being (because a perfect being would have full
knowledge, hence no room for doubt).
2. I doubt, therefore I am an imperfect being.
3. Yet I could know that I am imperfect only by having the concept of perfection;
therefore I do have the concept of perfection.
4. I could not have received the concept of perfection from something imperfect;
therefore my concept was not derived from myself.
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5. Therefore my concept of perfection was derived from something that is in fact
perfect.
6. Only God is in fact perfect, so I derived my concept of perfection from him, and
therefore he exists.
Do you find this argument convincing? If Descartes really has proved the existence of
God, then he has, by his reckoning, eliminated the evil genius. If he has eliminated the evil
genius, then mathematics is valid (because the only argument against math was derived from
the possibility of an evil genius). Also, Descartes now knows that his innate ideas were not
placed in him by an evil genius, so they may be true as well. Still, at this point, Descartes
remains in a nearly solipsistic universe. That is, with the exception of his knowledge of God,
Descartes does not know if anything other than his own mind exists. He does not even know if
he has a body. So his next task will be to determine whether an external world exists, and his
final epistemological task will be to determine what knowledge we can have of such a world.
Descartes asks whether or not it is possible that an external, physical world does not
actually exist. Descartes’s notion of the physical world is often referred to as extension, and
this is due to the constant question posed by Descartes of whether or not there exists anything
that “extends” past his own mind. To answer this question, Descartes says that the physical
world can be doubted methodologically, but not really. What does that mean? Well, it means
that the physical world can be technically doubted according to the rules of strict
methodological doubt, but that Descartes has no real reason to actually doubt its existence
apart from a rationalistic thought experiment. So is it possible that there is in fact nothing “out
there” that extends past our own minds? No! Because God…
“has given me no faculty to recognize that this is the case, but on the other hand, a very
great inclination to believe…that [my ideas of the corporeal world] are conveyed to me by
corporeal objects, so I do not see how He could be defended from the accusation of deceit if
these ideas were produced by causes other than corporeal objects. Hence we must allow that
corporeal things exist.”
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We know there is a physical world because if there is not, God is a deceiver, which is
impossible for God to be. But what is the nature of the corporeal objects that make up the
physical world? According to Descartes:
“Corporeal things exist. However, they are perhaps not exactly what we perceive by the
senses since this comprehension by the senses is in many instances very obscure and
confused…perceptions of light, sound, pain, and the like are very dubious and uncertain, and it
may happen that these perceptions contain some error.”
The upshot of Descartes’s conclusion is the following: the physical world that we know
as philosopher-scientists is not the world of appearance, the world presented to us by the
senses. It is the world as known by mathematical physics. It is, after all, the world as revealed to
us by the new sciences—the world of Galileo. The senses continue to be permanent deceivers.
They tell us that bodies contain colors, sounds, odors, tastes, and sensations of heat and cold.
But in fact what exists “out there” is whatever math can measure: extension, size, shape, part,
location, moveability, mass in motion, configurations of matter, light waves, and sound waves,
but not sensations such as colors, sounds, or tastes. These last three things are examples of
deceptive sensations because they exist only as immeasurable sensations and are thus
relegated to the category of subjective states, separate from objective reality. The molecular
structure of the American flag exists in reality, whereas the colors of the American flag exist
only as subjective sensations. (After all, our perception of red, white and blue is just the result
of light hitting our retinas.)
Here we ought to take note of Descartes’s success in creating a philosophical-theological
compromise. We get both Galileo and God in this system. Not only are Galileo’s world and God
both knowable, but both are also necessary. In fact, science rests on a godly foundation.
However, the soul (i.e. the self) is not the subject of science because science can know only that
which can be measured, and the soul cannot be measured. But it can be known immediately to
itself. In truth, the self knows itself before it knows the world. So Descartes leaves our souls to
ourselves (perhaps to be shepherded by the Church), and he leaves the physical world (Jupiter’s
moons included) to the scientists.
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Despite their historical differences, the epistemologies of Plato and Descartes are
strikingly similar. Both repudiate the senses as sources of true knowledge. Both find that there
is an intelligible order behind the flux of appearance. Both conclude that true knowledge must
be a priori. Both use mathematics as their model of knowledge. Both derive knowledge of the
world from knowledge of a higher reality (the Good for Plato and God for Descartes). Both find
the source of all knowledge in innate ideas located in the soul. These points sum up the
epistemological program of classical rationalism.
A Brief Introduction to Aristotle
Written by Ashton Trumble
Just as Plato (428 – 348 B.C.) was the most important student of Socrates (470 – 399
B.C.), Aristotle (384 – 322 B.C.) was the most important student of Plato. After the death of
Socrates, Plato founded The Academy in ancient Athens in his honor. This was essentially the
first university ever created. Some notable alumni include mathematicians Pythagoras
(responsible for the Pythagorean Theorem) and Euclid (founder of modern geometry).
Ultimately, though Aristotle agreed with many of Platos’ ideas, he disagreed with Plato’s core
concept of a “Form.” That is, Aristotle was not buying Plato’s “everything on Earth has a
transcendent archetype called a Form, and we can’t see it or touch it but trust me it’s there and
it’s the realest thing in existence don’t ask me how I know this” schtick. Aristotle did believe
that the “form” of a thing was important. Unlike Plato, however, Aristotle did not believe in a
kind of Form with a capital F. Indeed, Aristotle would remain in many respects faithful to the
doctrines of Plato but would ultimately reject the Theory of Forms as too “other worldly.”
Instead, Aristotle would argue in his first book—Physics—that all things have form (“form” just
meaning “shape”), but they also have matter. This idea that all existing entities are a
combination of both form and matter would be the basis of Aristotle’s entire philosophy. It
would also represent his main diversion from the philosophy of his teacher Plato. Finally, this
unity of both matter and form that Aristotle described would come to be known as
“hylomorphism” (“hylo” meaning “material” and “morph” meaning “shape”).
Aristotle believed that the world we are born into is the realest world in existence. In
other words, unlike Plato, Aristotle did not believe that this world is merely a shadow of its
more ultimate, “realer” version. Many people like to think of Plato as the “up” thinking
philosopher, whereas Aristotle is the “down” thinking philosopher. While a bit overly simplistic,
this is not a terrible way of viewing things. Aristotle was definitely much more concrete than his
teacher Plato; he literally brought Plato’s ideas down to Earth by claiming that the Forms must
be “imbedded in matter.” Aristotle believed that the distinction between form and matter was
only an intellectual distinction, a distinction that could be drawn in theory but not in reality. His
theory does not have the bias against “the visible world” that we see in Plato.
René Descartes’s Rationalism
Written by Ashton Trumble
Selected Portions of Meditations on First Philosophy Translated from Latin to English by
Ashton Trumble
In order to fully understand the epistemology (the theory of knowledge which seeks to
answer the question of ‘how do we know what we know?’) of René Descartes, we ought to first
review the epistemology of Plato. Indeed, though they are separated by many centuries,
Descartes and Plato are share several key similarities in their philosophical thought. You may
remember that, according to Plato, true knowledge requires a kind of transcendence of the
ever-changing flux of the material world. When we transcend this flux, we grasp—even though
temporarily—the permanent, rational order behind the changing physical realm. This reveals
that there exists an eternal, perfect “universal” archetype for every thing that exists; these
archetypes are the Forms. When we “know” a form—that is, when we recognize the
permanence behind the ever-changing physical world—we grasp on to something that is
completely rational. This “grasping” is an intellectual act of the mind, which, in its purest
manifestation, is exclusively formal (i.e. mathematical). Such an intellectual act can only take
place if there are certain innate ideas upon which it can be based. Knowing, then, is an act of
making the observable world intelligible by showing how it is related to an eternal order of
intelligible truths. These features of Plato’s epistemology are part of the program of
rationalism, one of the two key epistemological poles in Western thought.
Platonic rationalism was immediately countered by the philosophy of Plato’s student
Aristotle with what would eventually become known as empiricism. Yet rationalism managed to
dominate later Greek and Roman philosophy and all of the early Middle Ages, only to be
countered once again by a revival of Aristotelianism in the work of St. Thomas Aquinas in the
thirteenth century. But that’s a story for another time.
Rationalism achieved its fullest maturity in the seventeenth century in the work of René
Descartes (1596-1650). Before we inspect his version of rationalism, let us first take into
consideration the context in which it was created. As Alasdair
