He was a lawyer who never had a client—but he argued the case for rationalism, inveighing against the theretofore vague definitions of knowledge and truth, in his voluminous correspondence with the great thinkers and theologians of his age.
He joined the army of a Dutch prince at the age of 22—but he eschewed a military career to devote himself to the rigorous pursuit of knowledge through the study and application of mathematics and philosophy. He was French by birth—yet he died in Sweden after living most of his life in Holland.
Anomalies abound in the life of René Descartes, a man who, on the one hand, stands as a milestone on mankind’s long road to enlightenment and reason, and on the other, has had much of his life’s work disputed and derided.
The Procedural Rule
Rejecting the scholastic methods of his philosophical forebears, who sought truth by contrasting and comparing the views of accepted authorities, Descartes posited in “Meditations on First Philosophy” that a “firm and permanent structure” of knowledge requires building “anew from the foundation.” He determined to rid himself of presuppositions, ignore all but incontrovertible facts, and discount any evidence supplied by his senses.
To the extent that the use of this truth-seeking methodology—his Procedural Rule—succeeded in advancing the studies of optics, analytical geometry, and the theory of equations, Descartes shall be forever ensconced in the pantheon of intellectual giants. That his main contribution to philosophy was to establish the certainty of uncertainty suggests that his quest left him, as its chronicle left so many of his skeptical descendants, personally unfulfilled.
However readily one might accept Descartes’ process for challenging conventional wisdom by application of his Procedural Rule—and the fact that rationalism as a philosophical denomination was born with his “Discourse on the Method of Rightly Conducting the Reason”—it is clear that the “father of modern philosophy” was himself stymied by the limits of his senses and intellect. “[It] is not in my power to arrive at the knowledge of any truth,” he finally admitted.
Descartes was quick to add, however, that his Procedural Rule could ensure that he would never give “credence to any false thing.” Common sense, the sciences, mathematics, logic: In no domain is there indubitable truth provable by human methodologies, because of the undependable nature of our senses.
Yet pervading all of these realms is the consciousness of man, the inquiring and doubting self that is the only solid, certain, provable entity in Descartes’ dualistic universe, to wit: Cogito ergo sum. I think, therefore I am.
Failing His Own Test
René Descartes, an extraordinarily gifted man, brought his formidable mind to bear on the profound questions of many disciplines, but through a peculiarly human, undisciplined application of his own methodology arrived at any number of specious, spurious, even silly conclusions.
For instance, the notion that “animal spirits” in human blood interact with “thinking substances” of the brain to create a nerve-channel charge that enables the limbs—was this fanciful idea put through the Procedural Rule wringer? And did the great Renatus Cartesius display intellectual integrity and dedication to objective truth by abandoning his belief in a Copernican universe when it was pronounced heretical by the Catholic Church?
So where, outside of his analytical analog to Euclidian construction, or the fundamental law of reflection, or his inspired though embryonic assertions of the undulatory theory of light, is the consistency, the unassailability, of Descartes’ philosophy?
A Place of Primacy and Permanence
The man who shook “foundations to [bring] the downfall of the rest of the edifice”; the man who was first to challenge categorically the perceptions, assumptions, and sensations upon which entire classical belief systems were founded; the man who enshrined along with the doubt of the objective the certainty of the subjective; the man who extrapolated from that subjective certainty the existence of a God apprehended by reason—this man does, indubitably, occupy a place of primacy and permanence in the history of philosophy.
Today, many of his great and varied contributions to our knowledge of geometry, optics, anatomy, and mathematics—not to mention our knowledge of knowledge itself—are unknown to most people on the planet. Yet someday, perhaps, the great René Descartes will be more widely recognized for his grand, passionate, provocative reasoning.
Perhaps he will even be as revered and respected as modern celebrity philosophers Eckhart Tolle, Bono, Bill Cosby, or Tom Cruise. It could happen; I don’t know.
I only know that I doubt it.