Descartes Vs. Hume Essay, Research Paper
Exploring the Epistemology?s of Rene Descartes and David Hume
Beginning in the 17th century, traditional ideas were being questioned by
the new beginnings of science. Although many of the accomplishments during this
?scientific revolution? were in astronomy and mechanics, very important advances
along the whole borders of knowledge were also taking place. The revival of
skepticism, brought about by these new concepts, had many philosophers seeking
answers to questions such as: Do we know anything at all, and do the sciences give
us knowledge of reality? Rene Descartes, whom many consider to be the father of
modern philosophy, sought to kill skepticism for good. He gave his Cartesian quest
for certainty the center stage in his epistemology, or theory of knowledge.
Following Descartes, later in the 18th century, David Hume also broke away from
the religious dogma of the day to explain knowledge on a non theological basis.
However, His epistemology dismisses Cartesian methods as both unworkable and
barren. Instead, he adopts his own theories which counters the ideas of his of
predecessor, and casts a different view on the levels of certainty humans can
The Content and Objects of Knowledge–Rene Descartes
According to Descartes, we each contain within ourselves the criterion for truth
and knowledge. Although he does not reject the idea of God as a creator, he believed that
the responsibility of obtaining knowledge rests on the individual and no longer on
medieval ideals such as priest, popes, or kings. Descartes believed that in order to obtain
knowledge, there must be a rational method for reaching the truth, and the use of the
senses, or any experience can not be a reliable source. He also believed that this rationality
is universal, and therefore, the same for every individual. He believed that a priori, or
innate ideas existed within the soul, and in order to test their certainty, his reasoning
method, referred to as methodological doubt, must be used as a tool for distinguishing
ignorance from knowledge.
As founder of the Cartesian coordinates, Descartes believed that geometry
represented the ideal source of knowledge. Intending to extend the Cartesian certainty
of mathematics to all areas of human knowledge, he discarded the authoritarian systems
of the scholastic philosophers, who lacked method, and began with this methodological
doubt to obtain knowledge. This system resembles the axiomatic, geometric system.
Axioms, were self evident principals which were ?so clear and distinct? that they could
not be doubted, and therefore accepted as certain and undoubtedly contents of
knowledge . He discovered that these intuitively certain principals, (axioms), were the
foundations of which knowledge must be based on. He believed that intuition, not the
senses, provided the foundation of clear and distinct axioms. He explains that ?for true
knowledge of external things seems to belong to the [rational] mind alone, not the
composite of mind and body[senses]?
The Content and Objects of Knowledge–David Hume
Contrary to his rational predecessor, British philosopher David Hume approached
his epistemology with an empirical view. Because he denied miracles and other religious
dogmas, he believed that clarification was the first thing he needed to do in order to
remove them, as well as dissolve the Cartesian method of thinking. This is to say that he
wanted a clean slate (Tabula Ross.)To do this, he believed that, unlike Descartes axioms
(first principals,) perceptions were the main content of knowledge. Hume believed that a
prori ideas did not exist and that our ideas are not innate, but derived purely from
experience of ?perceptions. According to Hume, ?perceptions,? can be reduced to
impressions and ideas. He believed that humans learned ideas through impressions, and
that if there is no impression, there is no idea. .Therefore this clearly formed a
dependence of ideas on the initial impression that made them. Unlike Descartes belief that
reason is the same for every person, Hume believed that every individual?s perceptions
were his alone, and distinct from other people?s.
Hume believed that three principals of association bound perceptions together:
Resemblance, Contiguity (in time or place,) and Cause and Effect. By resemblance, Hume
uses the example of a picture of something evokes the thought of the original. For
Contiguity, Hume refers to the mention of an apartment building would invoke the
thought of other apartment buildings. And if one thinks of a wound, they would think of
the pain that is associated with it (cause and effect.) These are also Hume?s objects of
knowledge, and are used in the method to determine whether certainty exists.
Descartes decides to base his method on fours rules or laws..
The first rule was to never accept anything for true which was not clearly known
to be such; that is to say, avoid precipitance and prejudice, and to comprise nothing more
in judgment than what was presented to the mind so clearly and distinctly as to exclude all
grounds of doubt.
The second rule was to divide each of the difficulties under examination into as
many manageable parts as possible for its adequate solution.
The third was to conduct thoughts in such order that, by commencing with objects
the simplest and easiest to know, they ascend by little and little to the idea of the more
complex; therefore, assigning in thought a certain order even to those objects which in
their own nature do not stand in a relation of antecedence and sequence.
The forth and last rule was to make enumerations so complete, and reviews so
general, that it be assured that nothing was omitted.
It is clear that Descartes integrates his mathematical concepts into his
methodology. Therefore, his method of obtaining knowledge of internal and external
reality reflects mathematical deductive reasoning of these self-evident principals
(axioms) until the rational mind finds it clear and distinct enough to be indubitable.
Descartes applied doubt to his first principals before he granted complete certainty to
them. . His most important first principal and immovable truth, a truth on which he
would also lay down his foundation of knowledge, and define all that which he knows,
was Cogito ergo sume; I think therefore I am. He could not doubt the statement, and
therefore, his first principle was established. Descartes believed that no question “so far
removed from us as to be beyond our reach or so deeply hidden that we cannot discover
it”, provided only that we persevere and follow the right method.
Hume believed that Causation is the method of which humans reason. He believed
that it is causation that allows us to reach out beyond the limits of present sensation and
memories. With this in mind, Hume divided all human reason into two kinds: relations of
ideas–that is, reasoning found in mathematics and logic, such as 2+3=5; which is certain
not because it introduces us to such a world of realities, but simply because of how it
relates ideas to one another.
Hume also recognizes matters of fact–that is, reasoning derived from sense
perception such as the sun will rise tomorrow. These are clearly conceived related ideas
that could possibly be true, but the evidence is never great enough to amount to certainty.
Hume believes that all our reasoning of matters of fact beyond perception and memory is
founded on the relation of cause and effect. Causes are nothing more then projections
onto a supposed objective world from a feeling in the mind. We may be able to say one
event follows another, but we can not say that one event caused the other. For example,
night follows day, but day did not cause night. Contrary to Descartes belief that effects
must come from a cause, Hume believed that causes are senseless and not uncertain. It is
clear, therefore, that unlike Descartes, who used skepticism to arrive at truth, Hume was a
skeptic through and through.
The Certainty and limits of knowledge–Descartes
Although Descartes used methodical doubt, he only used it in order to establish
certainty. Descartes arrived at the conclusion that the universe has a mathematically
logical structure and that a single method of reasoning could apply to all natural sciences,
providing a unified body of knowledge. He believed he had discovered such a method by
breaking a problem down into parts, accepting as true only clear, distinct ideas that could
not be doubted, and systematically deducing one conclusion from another.
From this certainty Descartes expanded knowledge, step by step, to admit the
existence of God (as the first cause) based on reason and not faith, and the reality of the
physical world, which he held to be mechanistic and entirely divorced from the mind.
Descartes believed therefore, that human knowledge becomes the complete correlation of
reality. This is to say that there is no question ?so far removed from us as to be beyond
our reach or so deeply hidden that we cannot discover it? The mind is equally intelligent
however diverse the objects it considers; and those objects because of their perfect
enchainment are always equally intelligible.
Certainty and limits Hume
David Hume?s empirical line of inquiry called into question our common sense
beliefs about the source and support of our sense perceptions. Hume maintains that we
cannot provide a prior justifications for a number of our beliefs like, “Objects and subjects
persist identically over time,” or “Every event must have a cause.” In Hume’s hands, it
becomes clear that empiricism cannot give us an epistemological justification for the
claims about objects, subjects, and causes that we took to be most obvious and certain
about the world. Everything known, he said, depends on perception, but perception can
never get any evidence outside itself to verify anything. Real knowledge, in his eyes,
became completely impossible to achieve
In conclusion, both Rene Descartes and David Hume lived in a revolutionary and
turbulent time in history. This is to say that, the revolutionary impact of modern science
caused tremendous changes in the thoughts of scientists, philosophers, and men alike.
Many of Rene Descartes? and David Hume?s ideas are still used as the foundations of
modern thought today.