About Ignatius Insight
  Who We Are
  Ignatius Press
  Ignatius Press catalogs
  Catholic World Report
  Homiletic & Pastoral Review
  IP Novels site
  IP Religious Ed blog
  IP Critical Editions

The Two Most Important Philosophers Who Ever Lived | Peter Kreeft | The Introduction to Socrates Meets Descartes: The Father of Philosophy Analyzes the Father of Modern Philosophy's Discourse on Method

Print-friendly version


This book is one in a series of Socratic explorations of some of the Great Books. Books in this series are intended to be short, clear, and non-technical, thus fully understandable by beginners. They also introduce (or review) the basic questions in the fundamental divisions of philosophy (see the chapter titles): metaphysics, epistemology, anthropology, ethics, logic, and method. They are designed both for classroom use and for educational do-it-yourselfers. The "Socrates Meets . . ." books can be read and understood completely on their own, but each is best appreciated after reading the little classic it engages in dialogue.

The setting – Socrates and the author of the Great Book meeting in the afterlife – need not deter readers who do not believe there is an afterlife. For although the two characters and their philosophies are historically real, their conversation, of course, is not and requires a "willing suspension of disbelief ". There is no reason the skeptic cannot extend this literary belief also to the setting.

This excerpt is the Introduction to Socrates Meets Descartes.

Socrates and Descartes are probably the two most important philosophers who ever lived, because they are the two who made the most difference to all philosophy after them. Socrates is often called "the Father of Philosophy" and Descartes is called "the Father of Modern Philosophy." The two of them stand at the beginning of the two basic philosophical options: the classical and the modern.

At least seven features unite these two philosophers and distinguish them from all others.

First, each was an initiator, a revolutionary, virtually without predecessors. No other philosophers depended so little on previous philosophers, and no other philosophers made subsequent thinkers depend so much on them. Socrates' method, Socrates' questions, and Socrates' answers differed almost totally from the so-called pre-Socratic philosophers; and Descartes tried to begin philosophy all over again as if the two thousand years of it before him simply had not existed. No one else in the history of thought has ever done this as thoroughly as these two did.

Second, each began by doubting and questioning everything, or nearly everything, even the commonplaces everyone else took for granted. Both understood that the first and most important step of a truly scientific method is to assume nothing, or at least to question all assumptions, to get prejudices out, out from the subjective side of consciousness and into the objective side, where they can be part of the examinees rather than part of the examiners.

Many other philosophers agree with this, of course, but none ever did it more thoroughly or originally than these two. Socrates had few books, no schools, and little philosophical tradition before him to work with; Descartes had much, but deliberately doubted it all (or tried to). Thus both relied on the direct experience and thinking of the individual, not the authority and tradition of the community.

Third, each made the quest for the knowledge of the self the central philosophical quest, though they meant somewhat different things by it. What Socrates meant by "know thyself" was "know Man's essence, know universal human nature." What Descartes meant was "know your own existence as an individual."

They also undertook this quest for different reasons. Socrates' reason was obedience to the command of the god of the Delphic oracle, over whose temple "know thyself " was inscribed. Descartes' reason was to overcome the skepticism of many of the best thinkers of his time (especially Montaigne) by discovering the one absolute certainty that could be used as the starting point of a new, more certain philosophy: "I think, therefore I am." But both men turned to the "I", the self, the soul, the mind, as their fundamental interest, much more than any other philosophers had. (Descartes' only rivals here are Augustine, twelve centuries before him, and Pascal, his contemporary; Socrates had no other preceding or contemporary rivals at all.)

Fourth, each identified the self with the soul rather than the body. Each was a "dualist", that is, they believed that reality is dual (twofold): matter (including our bodies) and spirit (including our souls). No philosophers were more famous dualists than Descartes and Socrates (via his disciple Plato).

Fifth, each focused on the epistemological question, or "the critical problem" of How do you know? Socrates asked this question about every particular claim anyone made to know anything, while Descartes asked it about knowledge in general. Unlike Socrates, Descartes demanded a reason for trusting reason itself before using reason to construct a philosophy, as a carpenter might check his tools before building a house. Perhaps this is an answerable question, perhaps not. But in any case, no two philosophers ever focused more attention on the question How do you know? than these two.

Sixth, each offered a new method to philosophy, though both came to traditional conclusions through their new methods. In both cases, the new method demanded more severe criteria, tighter, stricter grounds for our beliefs and opinions. Each philosopher narrowed "reason". Before Socrates, it had included myth, intuition, and tradition. Without rejecting any of these older things, Socrates demanded something new: clear definitions and logical arguments. Descartes narrowed "reason" further, from "wisdom" to "science", from philosophical logic to scientific logic, from Socrates' "dialectical" (dialogue) method to the scientific method. No other philosophers ever offered new methods that changed philosophical thinking itself as much as these two. And no philosopher's method ever proved more popular, more universally imitated by his successors, than these two.

Seventh, each believed he was divinely commissioned to philosophize by a supernatural sign. For Socrates, it was the Delphic oracle, who, by announcing to Socrates' friend Chairophon that no one was wiser than Socrates, inveigled Socrates to question others to find someone wiser than himself, and in so doing inveigled Socrates to develop the Socratic Method of philosophizing by logical cross examination.

Socrates also confessed that he had a private "spiritual sign" or "divine voice", which often stopped him from some course of action but never specifically commanded any. Like most idealistic Athenian citizens of his time, Socrates had aspired to a political career, but the "divine voice" forbade him. So together, the Delphic oracle and the "divine voice" led him into philosophy. In his Apology, he defends not only himself but his troublemaking vocation of philosophizing: every single time he mentions philosophy in that speech, he mentions "the god" as its source.

Descartes, too, became a philosopher due to an apparent divine intervention. Already at age twenty three he was clearly a scientific genius, and he delayed publishing only because of the condemnation of Galileo. On the night of November 10, 1619, he had a life-changing dream in which he believed that the divine Spirit of Truth came to him and directed him to philosophize.

I need not add that this is not how most philosophers and philosophies begin. Socrates and Descartes are strikingly unusual and strikingly similar in these seven different ways. Yet they are also strikingly different from each other, as different as the ancient (classical) and modern (scientific) worldviews of which they were major founders.

So a dialogue between Socrates and Descartes is a dialogue between the two fundamental stages in the history of philosophy, the history of consciousness, and the history of Western culture.

Related IgnatiusInsight.com Articles, Excerpts, & Interviews:

The Comprehensive Claim of Marxism | Peter Kreeft
On Writing and Apologetics | Talking with Peter Kreeft
Seducing Minds With The Socratic Method | An Interview with Peter Kreeft
Socrates Meets Sartre: In Hell? | From Socrates Meets Sartre | Peter Kreeft
The Point of It All | From The God Who Loves You | Peter Kreeft
The Divinity of Christ | From Fundamentals of the Faith | Peter Kreeft
How To Read The Bible | From You Can Understand The Bible | Peter Kreeft
The Presence of Christ in The Lord of the Rings | From The Philosophy of Tolkien | Peter Kreeft
Abortion: What Can Be Done? | Introduction to Three Approaches to Abortion | Peter Kreeft
The Question of Hope | From Heaven: The Heart's Deepest Longing | Peter Kreeft
On Spiritual Warfare | From The Screwtape Letters | Peter Kreeft

Peter Kreeft, Ph.D., is a professor of philosophy at Boston College who uses that dialog format in a series published by Ignatius Press, called "Socrates Meets..." So far, Dr. Kreeft has written Philosophy 101 by Socrates, Socrates Meets Marx, Socrates Meets Machiavelli and Socrates Meets Sartre.

Dr. Kreeft has written more than forty books, including C.S. Lewis for the Third Millennium, Fundamentals of the Faith, Catholic Christianity, Back to Virtue, and Three Approaches to Abortion. His most recent Ignatius Press books include You Can Understand the Bible, The God Who Loves You, and The Philosophy of Tolkien. (A complete list of Ignatius Press books by Kreeft can be viewed on his IgnatiusInsight.com author page.)

If you'd like to receive the FREE IgnatiusInsight.com e-letter (about every 1 to 2 weeks), which includes regular updates about IgnatiusInsight.com articles, reviews, excerpts, and author appearances, please click here to sign-up today!


World Wide Web


Place your order toll-free at 1-800-651-1531

Ignatius Press | San Francisco
Web design under direction of Ignatius Press.
Send your comments or web problems to:

Copyright 2018 by Ignatius Press

IgnatiusInsight.com catholic blog books insight scoop weblog ignatius