In the 17th Century, there was no agreed-upon corpus of rules, standards, procedures and practices for doing science as we know it. Education was by scholastic reasoning, which constituted a closed system of ideas. It in effect was an elaborate game won by manipulating terminology--rather than the open-minded pursuit of truth. Explanation was vacuous and circular, trading upon obscure, non-testable "qualities" attributed to objects and persons. At best, genuine knowledge was seen to be gained principally by uncovering occult forces--discerning the hidden clues left by God.

Descartes broke with the scholastic tradition by arguing that truth about the external world is accessible to an intellect guided rightly. His method is "intuition", in the sense of seeing in a good clear light, boiling down what is perceived to its essentials, and proceeding logically from what is unknown to explain what is unknown. For Descartes, "philosophy" is the search for first causes and true principles which enable us to deduce the reasons for everything we are capable of knowing. The knowledge generated in this manner has three characteristics: a) unity (in contrast to the different truth domains of different disciplines); b) purity (not compromised by incoherence and inaccuracy) and c) certainty (of greater certitude than the probable truth of received opinions).

The Text: Discourse on the method of rightly conducting one's reason and seeking the truth in the sciences (hereafter, The Discourse)

The Discourse is an intellectual biography, recounting how Descartes came to adopt and develop his method. It was published in 1637, when Descartes was 41, and indeed was his first major publication. Descartes long hesitated to display his work to other European intellectuals. Part Six explains the reasons for this hesitation--having to do not only with fear of the Church's censorship, but with what he regarded as a highly personal, even private, method of gaining knowledge. The decision to "go public" was a complex one. In any case, the Discourse serves as a preface to three essays (on optics, geometry and meteorology) which were intended to display his method at work.

Descartes divided The Discourse the work into six parts, whose content he summarizes in the first paragraph. The Discourse mixes three kinds of material: narrated bits of his history; descriptions and examples of his method; and a debate about its value. All have significance for the Principia theme, as well be suggested in the following outline.

Note: the page references for the discussion questions follow the standard pagination for Descartes' works. These numbers, found in the page margins, run from 1 through 78.

Part One

Descartes (hereafter "D") reviews his education and the standard subjects of his day, and explains why he "abandoned the study of letters".

1) What does D believe about the distribution of human "good sense"? (1-2) Who has the capacity to gain true knowledge about the world?

2) What does it take to gain knowledge: brilliance or sheer hard work?

3) What did he find attractive about the traditional subjects of study? (5-6)

Part Two

D relates with the famous episode of the stove-heated room. At the age of 24 (1619), cooped up indoors by bad weather, he began to sift and sort his ideas, discarding those which he could not confirm as true by the sheer power of thought. He devised four rules for proceeding in this "long chain of reasoning".

6) D explains what he is trying to accomplish by using an analogy: he presents the sum of human knowledge as the sum total of the buildings in a city. What does he intend to do--tear down the whole city, or only part of it? (13-15)

Is his image still viable to symbolize the accumulation of knowledge today?

7) Why isn't D willing to learn to accept the authority of others? Why is he his own best "guide"? What have his years of travel taught him? (15-16)

Are his reasons still valid? Why or why not?

8) How widely does he recommend his method to be used? (15) Is a contradiction implied between his breezy assumptions about human intelligence (Part I) and his more cautious statements here?

9) Enumerate D's four "rules" for discovering truth.

10) What degree of success did D enjoy with this method? What benefits did he derive from it? (21-22)

Part Four

To illustrate his method, D describes the steps by which he discovered and established two basic principles of knowledge. First, he exercised a radical skepticism, rejecting the testimony of the senses and of logical proofs. He retrenched in one unassailable certainty: that because he was aware of himself thinking, he could be confident that he existed--as a rational soul, distinct from his body.(31-33) Second, because he could imagine of a kind of "perfection" which includes existence as one of its attributes, he could be confident that God exists.(33-37)

16) Note that D at this point rejects the procedure which is widely thought to be central to the scientific method: inductive reasoning which accumulates observations in order to draw conclusions. Why does D consider it necessary to reject what our senses tell us, in establishing a firm foundation for knowledge? (32)

17) These days it is popular to understand our minds as integrally linked to our bodies. Some recent scholars have argued that the Western bent for exploiting nature is anchored in a "Cartesian" (derived from Descartes) split between mind and body, where the mind is exalted as the route to truth, while the body is cast aside as mere matter. Is D open to this charge? Is the rational soul (=mind) the measure of human value? (32-33; see also 56-60)

18) How does D conceive of God? (34-35)

19) Why does D need to understand God in this way, for his project of reconstructing human knowledge (38-40)? What, if anything, is gained for the scientific method by postulating such a God?

20) Why do dreams pose such a threat to D's system?