Meditations is a discussion of metaphysics, or what is truly real. In these writings, he
ultimately hopes to achieve absolute certainty about the nature of everything including
God, the physical world, and himself. It is only with a clear and distinct knowledge of
such things that he can then begin understand his true reality. Descartes starts by looking
at our usual sources for truth. Authority, which is churches, parents, and schools, he says,
are not reliable sources for truth because time shows we all die, and that we are
eventually proved wrong, much in the same way the accepted truths of science have
changed dramatically over the course of history. Also, he considers the generally excepted
view that our senses dependably report the absolute nature of reality. Simiar to authority,
Descartes discards the senses as a source of truth because of the “Dream Argument” or
the belief that based on the senses there is no definite way of proving that you are
dreaming or that you are awake. Therefore it is possible that everything we believe is
false, making the senses an unreliable source. Upon establishing this, Descartes doubts
the existence of a physical or external world. Despite that he has an idea of things in the
world, he has no way of knowing if they exist past his own mind. Another point he
addresses is mathematics. He soon realizes math’s truth isn’t completely reliable because
of the “Demon Hypothesis”, which acknowledges the possibility of an all powerful being
that is deceiving him about everything, including mathematics. As a result, Descartes
ponders the possibility that he has no way of being completely positive about anything,
even his existence. It is only after some deliberation that he decides that it is impossible
to be incorrect about everything because he has doubt, and to posses doubt, there must be
a doubter. Hence, he doubts, therefore he exists. With the assurance of his existence, he is
presented with the deeper question of what he, himself, actually is. Descartes knows that
he is not just a body based on his doubt of the senses. Despite the fact that he feels he is
not a body, he does believe he has properties, such as doubt, that make him a substance.
From this he concludes that his is an immaterial substance and that his essential property
is self-consciousness because you can have no real proof of yourself except through your
own thoughts or consciousness. Descartes states this belief in the statement, “I’m aware
that I’m aware.” He established the first absolutely certain foundation of truth that he was
seeking. Hoping to discern the existence of anything else aside from himself, an
immaterial substance, Descartes considers a variety of ideas he has within his mind and
contemplates whether he could have conceived them himself or not. Predominantly, he
finds that he has the idea of a perfect being. Descartes is imperfect in that he is not all
knowing (omniscient) or all powerful (omnipotent), and is most certainly mortal. Another
way in which Descartes proves the existence of God is through an “ontological” proof.
This states that an essential property of a perfect being is existence, or that the idea of a
perfect being proves that there must be one because the definition of a perfect being must
include that it exists. At this point he observes that his existence depends upon God, or
that only God exists necessarily, while everything else exists contingently. Descartes
concludes that the reliability of mathematics can no longer be doubted because God
guarantees the truth of all self-evident ideas,(self-evident not meaning obvious), but ones
that can be calculated through mathematical physics. Therefore, Descartes now knows
that a perfect being exists and that he is not alone. knows what one will do in the future,
then one must do what God knows he will do in the future. This means that one has no
choice in what God knows he will do, since God already knows that he will do it,
therefore eliminating his freewill. These are some of the considerations when thinking
about Descartes proof of God's existence. In the Sixth Meditation, the last section in our
text, Descartes hopes to prove the existence of the external world and matter (physical
objects located in space). To do this first he again acknowledges the existence of minds as
an immaterial substance and God. Next, he shows that external ideas, or images of things
are neither fashioned by himself or by God because he has ideas of things that don't
depend on his will. From this he can say that he will know matter exists if its image was
not a product of the mind or God. To prove this credits the existence of external ideas to
the imagination, which is the psychological power of receiving and processing images.
Then he says that thinking is his only essential property which excludes imagination
because thinking or consciousness doesn't require images. He states that the only reason
we have an imagination is that we have temporary physical bodies. He then concludes
that he is not the cause of his external ideas. To show that God is not the cause of external
ideas or images he first states that it is self-evident that external things refer to objects in
space. Subsequently, if God is causing these ideas, then they are not in space. But that
would mean that God is deceiving him about a self-evident idea, which can't be possible
because holding to the truth that God is perfect, God is incapable of deception.
Consequently, God is not the cause of these external ideas because God ensures the truth
of self-evident ideas. To summarize, neither God nor Descartes is the cause of external
ideas, therefore proving that matter exists. Now that Descartes has established the
existence of the external world, he hopes to further his understanding of its true nature.
He finalizes that we can accept as accurate those parts of our external ideas, which are
self-evident, or those that can be mathematically represented. Descartes calls these
characteristics that can be represented mathematically primary qualities, such as shape,
spacial location, weight, and height. All those which cannot be deduced utilizing
mathematics, like color, taste, feel, smell, he refers to as secondary or subjective qualities.
They cannot be considered accurate representations of the external world because they're
only particular ways in which the human body perceives the world. It is with these
preceding ideas which he accepts the nature of the external world. The obvious conflict
between science and religion is another concern that Descartes hopes to resolve. The
reason these two ideologies seem to be conflicting is because they both provide
competing and different ideas about the true nature of reality. Religion offers that the goal
of human life is acquisition of salvation and eternal life. Conversely, what science tells us
is that the world is completely deterministic or all just a course of random evolution.
Descartes feels that the two, mind and matter, are in completely different arenas, both of
which were created by God. The mind deals chiefly with freedom, and personal
responsibility, which lies in the field of religion. Whereas matter is more connected to
science, buts doesn't negate the influence of God because God provided us with a system,
mathematics, to better understand the physical world around us. Thus, if accurately
comprehended, no conflict should arise between science and religion. Descartes' focus in
Meditations is absolute certainty. To achieve this he first must strike all that he has come
to accept as false and only then start to rebuild is foundation of knowledge. To insure the
integrity of his newly acquired understanding of reality, he uses the method of doubt. It is
only through this method that he can grasp the true nature of reality. After establishing the
existence of himself, God, and the external world through this method, Descartes feels he
now possess a clearer picture of reality.