The Philosophy of Rene
Descartes

General
Observations

Life
and Works

The
Laws of the Cartesian Method

Metaphysics:
From Methodical Doubt to "Cogito Ergo Sum"

From
"Cogito" to the Proof of the Existence of God

The
"Res Extensa"
and the Mechanism of the Universe

The
Dualism of Substances

Ethics

The
Development of Cartesian Rationalism

Rene Descartes (1596-1650)

I.
General Observations

Rene
Descartes (picture) is
justly considered the father of modern philosophy and the founder of the
rational method as applied to philosophical research. In fact, he is the first
philosopher to begin with the impressions which are in our intellect
(intellectual phenomenalism) and lay down the laws
which reason must follow in order to arrive at reasonably certain philosophical
data.

This phenomenalism does not find its full development in
Descartes. Indeed, Descartes reaches metaphysical conclusions which are no
different from those of Scholastic philosophy. He maintains the transcendency of God, upholds human liberty and Christian
morality.

But
pantheism is sown deep in every form of immanentism.
The rationalism of Descartes was to be quickly and logically bent in this
direction by Spinoza, while other Cartesians, such as Malebranche
and Leibniz, tried -- with less logic -- middle-of-the-road solutions between
pantheism and the transcendence of God.

II. Life and Works

Descartes
was born in 1596 at La Haye in France of a noble family, and was
educated in the celebrated Jesuit college of La Flche, where he received a
philosophical and scientific education according to the principles of the
Scholasticism of his day. Not fully satisfied with this first education, and
urged on by a desire to better himself, he went first to Paris, and then enlisted in the army
during the Thirty Years' War.

On the
ninth of November, 1619, while still in the service in winter quarters, he gave
himself up to meditating on how to apply the mathematical method of the
sciences to philosophy. During this time he conceived the four laws which he
described in his work Discourse on Method. He then abandoned the army,
but before dedicating himself completely to
philosophical meditation he undertook long travels throughout Europe.

In
1629 he retired to Holland, which offered him tranquillity for meditation and writing. He remained there
until 1649. During these twenty years he wrote nearly all his books. In 1649 he
went to the court of Queen Christina of Sweden, being summoned there by the
Queen, who wished to study philosophy under his direction. Unable to resist the
rigors of winter, he died in Sweden during 1650.

Descartes
was a scientist and a philosopher. As a scientist he is noted for his studies
in mechanics, physics and mathematics. As a philosopher he opened the period of
modern philosophy.

Not
all the philosophical works written by Descartes were published during his
lifetime. His Rule for the Direction of the Mind was published
posthumously, as was his treatise on The World.

The
philosophical works published by the author were four: Discourse on Method;
Meditations on First Philosophy, in which he proves the existence of God
and the immortality of the soul; Principles of Philosophy, in four
books, a systematic work reviewing the entire thought of the author; The
Passions of the Soul, treating of the problem of morality.

III. The Laws of the
Cartesian Method

Descartes,
in his work Discourse on Method, after giving a criticism of the
education which he had received (a criticism which is indirectly an attack on
the Scholasticism of his day), goes on to set up the new method, according to
him, must be the basis of all scientific and philosophical research.

These
laws are four:
To accept
nothing as true that is not recognized by the reason as clear and
distinct;
To analyze
complex ideas by breaking them down into their simple constitutive
elements, which reason can intuitively apprehend;
To
reconstruct, beginning with simple ideas and working synthetically to the
complex;
To make an
accurate and complete enumeration of the data of the problem, using in
this step both the methods of induction and deduction.

To
better understand these laws, we must note that for Descartes the point of
departure is the ideas, clearly and distinctly
known by the intellect -- the subjective impressions on the
intellect. Beyond these clear and distinct ideas one cannot go, and hence the
ultimate principle of truth consists in the clearness of the idea. Clear and
distinct intuitions of the intellect are true. For Descartes, such clear and
distinct intuitions are thought itself
("cogito") and the idea of extension.

Having
arrived at this starting point (clear and distinct ideas), the intellect begins
its discursive and deductive operation (represented by the second and third
rules). The second law (called analysis) directs that the elementary notions be
reunited with the clear and distinct ideas (the minor of the Scholastic
syllogism). The third law (synthesis) presents them as the conclusion flowing
from the premises. The final law (complete enumeration) stresses that no link
in the deductive chain should be omitted and that every step should be
logically deduced from the starting point (i.e., from the clear and distinct
ideas). Thus, working from one step to the next, there will be achieved a
system of truths all of which are clear and distinct, because all participate
in the same degree of truth enjoyed by the first idea, which was clear and
distinct.

This,
as we know, is the method adopted in mathematics. Descartes transferred it to
philosophy with the intention of finding clear and distinct concrete ideas, and of deducing from these,
through reason alone, an entire system of truths which would also be real or
objective.

The Aristotelio-Scholastic method (as
well as that of classical realism in general) is also deductive, but it is very
different from that of Descartes. Scholastic deduction is connected with
objective reality because ideas are abstractions of the forms of the objects
which experience presents. Thus both the concreteness of the ideas and the
concreteness of the deductions based on these ideas are justified.

In
Descartes ideas do not come from experience, but the intellect finds them
within itself. Descartes declares that only these ideas are valid in the field
of reality. Thus the concreteness (or the objective validity) of an idea is
dependent upon its own clearness and distinction.

IV. Metaphysics: From
Methodical Doubt to "Cogito Ergo Sum"

Descartes,
as a result of the principles already established in his method, had first of
all to seek out a solid starting point (a clear and distinct concrete idea),
and from this opens his deductive process. To arrive at this solid starting
point, he begins with methodical doubt, that is, a doubt which will be the
means of arriving at certitude. This differs from the systematic doubt of the
Skeptics, who doubt in order to remain in doubt.

I can
doubt all the impressions that exist within my knowing faculties, whether they be those impressions which come to me through the senses or
through the intellect. Indeed, I may doubt even mathematical truths, in so far
as it could be that the human intelligence is under the influence of a
malignant genius which takes sport in making what is objectively irrational
appear to me as rational.

Doubt
is thus carried to its extreme form. But notwithstanding this fact, doubt
causes to rise in me the most luminous and indisputable certainty. Even
presupposing that the entire content of my thought is false, the incontestable
truth is that I think: one cannot
doubt without thinking; and if I think, I exist: "Cogito ergo sum."

It is
to be observed that for Descartes the validity of "Cogito ergo sum"
rests in this, that the doubt presents intuitively to
the mind the subject who doubts, that is, the thinking
substance. In this, Cartesian doubt differs from that of St. Augustine ("Si
fallor, sum"), which embodies a truth
sufficiently strong to overcome the position of Skepticism. In Descartes,
"Cogito ergo sum" is assumed, not only in order to overcome the
Skeptic position but as a foundation for the primary
reality (the existence of the "res cogitans"), from which the way to further research is
to be taken.

This
is the point which distinguishes the classic realistic philosophy from
Cartesian and modern philosophy. With Descartes, philosophy ceases to be the science of being, and becomes the science of thought (epistemology). Whereas, at first, being conditioned thought, now it is
thought that conditions being. This principle, more or less realized
by the philosophers immediately following Descartes, was to reach its full
consciousness in Kant and modern Idealism. (See: Meditations on First
Philosophy, I and II; Discourse on Method, IV.)

V. From
"Cogito" to the Proof of the Existence of God

The
"cogito" reveals the existence of the subject, limited and imperfect
because liable to doubt. It is necessary to arrive at an objective and perfect
reality, i.e., to prove the existence of God.

Descartes
makes use of three arguments which can be summarized thus:
"Cogito" has
given me a consciousness of my own limited and imperfect being. This
proves that I have not given existence to myself, for in such a case I
would have given myself a perfect nature and not the one I have, which is
subject to doubt.
I have the idea of the perfect: If I did not possess
it, I could never know that I am imperfect. Now, whence comes
this idea of the perfect? Not from myself, for I am imperfect, and the
perfect cannot arise from the imperfect. Hence it comes from a Perfect
Being, that is, from God.
The very analysis of the
idea of the perfect includes the existence of the perfect being, for just
as the valley is included in the idea of a mountain, so also existence is
included in the idea of the perfect. (the
argument of St. Anselm). (See: Meditations on First Philosophy, V; Discourse
on Method, IV.)

Regarding
the nature of God, Descartes ascribes to it more or less the same attributes as
does traditional Christian theistic thought. In Descartes, however, these
attributes assume a different significance and value. God, above all, is
absolute substance: the only substance, properly so-called (hence the way is
open to the pantheism of Spinoza). An attribute which has great value for
Descartes is the veracity of God.

God,
the most perfect being, cannot be deceived and cannot deceive. Thus the
veracity of God serves as a guarantee for the entire series of clear and
distinct ideas. They are true because if they are not true, I, having proved
the existence of God, would have to say that He is deceiving by creating a
rational creature who is deceived even in the apprehension of clear and
distinct ideas. Thus, with the proof of the existence of God, the hypothesis of
a malignant genius falls of its own weight.

Regarding
the origin of ideas, Descartes holds that the idea of God, all primitive
notions, all logical, mathematical, moral principles, and so forth, are innate.
God is the guarantee of the truth of these innate ideas. Alongside these innate
ideas Descartes distinguishes two other groups of ideas:
the adventitious, which are derived from the
senses; and
the fictitious, which are fashioned by the thinking
subject out of the former.

Both
groups are considered of little worth by Descartes because they do not enjoy
the guarantee of the divine veracity, and hence are fonts of error. Only innate
ideas and the rational deduction made from them have the value of truth. (See: Meditations
on First Philosophy, III.)

VI. The "Res Extensa" and the
Mechanism of the Universe

Descartes
proves the existence of the world, not from the testimony of our experience of
this fact but from the innate idea of the "res extensa." We have a certain idea that is clear
(presenting but one quality, extension), and it is distinct from the "res cogitans." This idea,
granted the veracity of God, cannot be false; hence the world exists, and its
principal attribute is extension.

Concerning
the nature of this corporeal world, Descartes distinguishes between what is
presented to us through the senses (colors, odors, tastes, tactile sensations)
and that which comes by way of the intellect, i.e., dimension, figure, weight,
position, motion. The first, not guaranteed by the veracity of God, do not have
objective value; they are secondary qualities, modes with which the subject
represents reality. The second which, according to Descartes, must be innate
ideas, are primary qualities and are guaranteed by the veracity of God; hence
they are real and objective.

The
Cartesian World is characterized by the essential attribute of extension
("res extensa"),
which is infinite. In this extension the power of God has placed force and
movement, which are determined by the principle of absolute causality. Not
purpose (finalism), but mechanical determination (matter and mathematical laws
of motion) governs the succession of phenomena in the physical world, in the
"res extensa."
The world is a machine. The inorganic world, plants and animals, and even man,
as far as his body is concerned, are machines governed by the laws of causality
of motion.

VII. The Dualism of
Substances

The
entire Cartesian system rests upon a metaphysical dualism: "res cogitans" (God and the
human soul) and "res extensa"
(the corporeal world). These two realities are irreducible, in so far as
thought, liberty and activity are essential to the world of the thinking being,
and extension, mechanical determinism and passivity are essential to the world
of the "res extensa."
All reciprocal action between the two substances is excluded because it is
impossible. Thus there is opened up the problem which was later to be taken up
by rationalism: the determination of the relationship between spirit and
matter; between God (the infinite spirit) and the world (finite matter).

This
problem presented even graver difficulties in connection with the Cartesian
concept of substance -- that which exists without need of the concursus of any other to exist. Such a definition of
substance is applicable only to God, who because He is causa
sui, is a substance
that has no need of the concursus of another in order
to exist. But finite beings also are substances; and although Descartes had
added that finite beings need the concursus of God in
order to exist, the passage to the monistic concept of single substance appears
quite open; this was to be the point of departure for Spinoza.

To
this we must add the fact that Descartes considers thought not as an act, but
as the thinking substance ("res cogitans"), that is, as a soul, whose essence is
thought. Now such an identification belongs only to God; hence it is easy to
see in this teaching of Descartes the danger of unifying the concepts of man
and God ("homo -- Deus") and hence the latent danger of pantheism.

In the
world of Cartesian matter, there exist no qualities, but only quantity, matter
and motion, which act fatally, necessarily and mechanically. The mechanistic
concept was to be inherited by Rationalism and Empiricism, which considered the
world as a huge machine acting through mechanical
forces, without purpose.

VIII. Ethics

Cartesian
Rationalism finds its application even in ethics. For Descartes, ethics is the
science of the end of man, and this end must be determined by reason. Before
reason can arrive at the knowledge of such an end, and of the means of reaching
it, the philosopher and only the philosopher must construct a provisory morality,
a model of life capable of assuring him tranquillity,
a standard which he will follow until such time as definitive and rational
morality appears to his reason. Provisory morality is made up of a few
precepts: Live according to the politico-religious opinions and customs of the
country; follow mean (i.e., moderate) and not extreme opinions; govern yourself
with constancy, without letting yourself be distracted by opportunistic
considerations. In a word, live in such a manner as to assure yourself the greatest tranquillity.

Regarding
definitive morality, Descartes holds to the full liberty of God, so that all
depends on the divine liberty. God, if He so wished, could have created a world
governed by moral principles opposed to those which hold today. Such an idea
brings ethics to the brink of disaster, for a morality like this would not find
its justification in the absolute essence of God but in the arbitrary act of
His will.

Granted
the present order of creation, Descartes recognizes that the end of man is
virtue and happiness. The actuation of this end is brought about through reason
-- through the knowledge of God, of the soul, and of the world. It is attained
through knowledge of God because God is the creator and unifier of the
universe; of the soul, because the soul makes clear to us our superiority over
material nature; of the physical world, because, governed by causal necessity,
it teaches man the virtue of resignation and indifference in the face of the
evils of life.

As is
evident, Cartesian morality does not greatly differ from Stoic ethics in which
the wise man appeals to reason in order to assure himself
of tranquillity and felicity.

IX. The Development of
Cartesian Rationalism

Descartes
left two questions unsolved:
the determination of the
relationship between the infinite substance (God) and finite substance
(the world), and
the relationship between the
spirit-substance (the soul) and the extended substance (body).

To
fill the gap which he left between the infinite and finite, between spirit and
matter, there were three possible solutions to be had through recourse to
earlier philosophers. All three solutions were tried and developed by later
philosophers: Spinoza, Malebranche and Leibniz, whose
systems can justly be considered as developments of the rationalistic premises
of Cartesian principles.

The
first possible solution lay in uniting Cartesianism
with Platonism and conceiving of the two Cartesian substances
(thought-substance and extended substance) as attributes deriving from a single
divine substance. This was the solution of Spinoza, the strongest and most
coherent of the Cartesian thinkers. He abolished the distinction between finite
and infinite, and explained monistically and pantheistically the procession of the finite from the
infinite. Spinoza answered the first of the unsolved questions, that of the
relationship between God and creatures. But he maintained the second
distinction and determined the relationship between soul and body by a
psycho-physical law: That which is produced in thought by its very nature finds
determination in extension (body).

The
second possible solution came from Augustinianism. Augustinianism, faced with
the impossibility of deriving concepts from experience, had recourse to God, to
a divine illumination in which God actually implants ideas in the human
intellect. This supernatural intervention or influence could be extended to all
finite reality in such a manner as to fill in the gap between the infinite and
the finite, between spirit and matter, through the intervention of God Himself.
This was the solution taken by Malebranche, according
to whom creatures are the simple occasions; a direct intervention of God is the
direct cause of all effects (Occasionalism).

As a
Christian Malebranche maintains the distinction
between God and the world, two forces which were unified in Spinoza. But in
determining the relationship between God and the world, Malebranche
also has recourse to God. This he achieves in such a manner that the immanentism latent in Cartesian Rationalism is not revealed
in the concept of substance but in the relationship between the two substances.

The
third possible solution was sought in bringing Cartesian Rationalism into
harmony with Aristotelian Scholasticism, and attempting to fill in the
relationship between spirit and matter with the concept of potency flowing
spontaneously into act according to a law pre-established by God. This law
would also explain the relationship between the finite and the infinite. The
monad of Leibniz is developed according to a pre-established harmony; its
development is a passage or transition from a potential state to a state of
representation.

Despite
these intrinsic deficiencies and notwithstanding the opposition which Cartesianism caused from its first appearance both in the
field of philosophy (Gassendi, Hobbes) and in that of
religion (both Catholic and Protestant), Cartesianism
spread rapidly throughout Europe and represented the dominant thought of the period. It
influenced all branches of culture. Catholic thinkers for example, those at
noted centers like the Paris Oratory and the Benedictine abbey of Port-Royal,
favored the supereminent position it gave to God and
the soul. The Jansenist polemics which Cartesianism instigated are a proof of this; scientists
liked the geometric spirit of the system; philosophers and litterateurs were
pleased with the clear and distinct ideas and the spirit of criticism carried
out according to rational methods. The classic land of Cartesianism, naturally, is France during its golden age of
literature, the age of Louis XIV.

Empiricism
also developed along with Cartesian Rationalism, and felt its influence.
Certainly Empiricism is opposed to Rationalism as sensitive and intellective
knowledge are in opposition. Nevertheless, it felt the influence of Cartesianism, first in a negative sense, in so far as
Empiricism now rose to reaffirm its premises in its debates with Rationalism
(Hobbes, Locke); in a positive way it was also influenced in so far as the
principle of immanence in common to both Empiricism and Rationalism. We may
conclude that Cartesianism, directly or indirectly,
is that predominating tendency in the philosophy of this period; it prepares
the way for Illuminism, and through Illuminism it reaches Kant.