In part 6, Descartes cautiously touches on possible conflicts
with the church over his ideas about physical science. Finally,
he implores his readers to read carefully, apologizes for writing
in French rather than Latin, and vows to shun fame and fortune in
the name of pursuing truth and knowledge.
Analysis
Discourse on the Method (1637) was Descartes’
first published work. He wrote the book in French rather than Latin,
the accepted language of scholarship at the time, because he intended
to explain complex scientific matters to people who had never studied
them before.
Descartes’ education was based on the Aristotelian model
of reasoning, which held that scientific knowledge is deduced from
fixed premises. This model is based on the syllogism, in which one
starts with a major premise (“Virtues are good”) and a minor premise (“kindness
is a virtue”), then draws a conclusion from the two (“therefore,
kindness must be good”). Descartes wondered whether he could be
certain of the premises he had been taught. He was reasonably convinced
of the certainty of mathematics (at which he excelled), but the
other sciences seemed shaky to him because they were based on philosophical
models rather than rational tests, which seemed to Descartes the
only sound method of discovery. His revolutionary step was to attempt
to solve problems in the sciences and philosophy by applying the
rules of mathematics. His work, however, is remembered for his development
of a method rather than his work in the physical sciences, which
is now considered flawed and obsolete.
Descartes initiated a major shift away from Aristotle
with the notion that individuals should examine problems for themselves rather
than relying on tradition. The four rules for individual inquiry
he outlines in Part Two are a summary of the thirty-six rules he
intended to publish as Rules for the Direction of the Mind (published
posthumously). In essence, the first rule is about avoiding the prejudices
that come with age and education. The second rule is a call for
breaking every problem into its most basic parts, a practice that
signals the shift from the traditional approach to science into
an approach more in line with mathematics. The third rule is about working
from simple elements to the more complicated elements—what math
teachers call “order of operations.” The fourth rule prescribes
attention to detail.
Descartes’ imposition of this method on scientific inquiry
signals the break between Aristotelian thought and continental rationalism,
a philosophical movement that spread across parts of Europe in the
seventeenth and eighteenth centuries, of which Descartes is the first
exemplar. Aristotelian science, like rationalism, proceeds from first
principles that are assumed to be absolutely true. Aristotelians, like
Descartes, proceed from those first principles to deduce other truths.
However, the principle truths accepted by Aristotelians are less
certain than the ones Descartes hopes to establish. By undertaking
to doubt everything that cannot be deduced with pure reason, Descartes
undermines the Aristotelian method. For centuries, scholars had
based their philosophy on sense perception in combination with reason.
Descartes’ new philosophy instead proceeds from doubt and the denial
of sensory experience.
Continental rationalism held that human reason was the
basis of all knowledge. Rationalists claimed that if one began with
intuitively understood basic principles, like Descartes’ axioms
of geometry, one could deduce the truth about anything. Descartes’
method is now used most often in algebraic proofs, geometry, and
physics. The gist of the method is that, when attempting to solve
a problem, we have to formulate some sort of equation.
