Lecture Supplement on Descartes

Descartes lived from 1596 to 1650. Between 1618 and 1621 he pursued a study of mathematics which resulted in the discovery and formulation of what we now call “analytic geometry”—that branch of mathematics which relates the algebraic and geometric studies. The “Cartesian Coordinate System” you were taught in High School gets its name from him. He also did important work in the fields of physics, astronomy, and optics--his account of the movement of the planets (each planet moved by a vortex having the sun at its center--one eddy for each planet) was the accepted theory until replaced by Newton's (who devoted much of the Second Book of his Principia [1687] to the refutation of Descartes' theory). The Meditations on First Philosophy was published in 1641. To understand his period (the Early Modern Period), we need a bit of historical background.

In his “The Recovery of Practical Philosophy,” Stephen Toulmin provides an excellent “introduction” to this time In making his point regarding the turmoil which arose in the late 16^th and early 17^th centuries, he appeals to John Donne’s (1572-1631) “An Anatomy of the World” (1611) citing especially these lines of the poem:

And new Philosophy calls all in doubt,
The Element of fire is quite put out;
The Sun is lost, and th’earth, and no man’s wit
Can well direct him where to looke for it....
‘Tis all in peeces, all cohaerance gone;
All just supply, and all Relation:
Prince, Subject, Father, Sonne, are things forgot,
For every man alone thinkes he hath got
To be a Phoenix, and that there can bee
None of that kind, of which he is, but hee.[1]

To understand how this can provide a picture of the “early modern world-view,” however, we must first understand the “medieval world-view.” The best way to understand the medieval period is by adopting the metaphor contained in the title of Arthur Lovejoy’s The Great Chain of Being.[2] This world-view emphasized a static, traditional picture of the universe and of our place in it. The universe was viewed as a rational whole, and there was a complete agreement of faith and reason. This view emphasized talk of heavenly spheres, relied upon Aristotelian science and logic, upon feudal social conditions, and had could easily countenance the uniqueness condition entailed by the phrase “The Church.” Each individual knew his/her place—sons and daughters did not have to worry about what their future career would be! Latin commentaries of earlier authors were studied in the universities.

At the transition between the Ancient and the Medieval periods of our culture Augustine didn’t simply hold that there was an agreement between faith and reason, he held that faith provided a transcendental, absolute, and personalistic standard against which all judgments were to be measured—the Catholic deity. In his version of the Aristotelian teleology,[3] for example, everything had its purpose and for him, unlike Aristotle, this was supplied by this deity. That is, the Medieval Aristotelian/Augustinian view is offered within the Catholic context. Here a discussion of a number of St. Augustine’s [353-403] views helps clarify this period. At the end of the Roman period according to Peter Gay, Augustine

...recommended the gradual replacement of pagan by Christian classics, and the expurgation of all obnoxious passages from ancient literature, so his very commendation of the human understanding has a new and unclassical tone. Ipsum credere nihil aliud est quam cum assensione cogitare—“to believe is itself nothing but to cogitate with assent,” might be read (and has been read by [Christian] apologists)[4] as the demand that religious faith be tested by rational investigation. But the statement is antithetical to [the] antique [that is, Ancient]...conception of philosophy: it stresses, not the will to criticism, but the will to believe. Augustine sees man as unhappy; puzzled by himself, his world, and his destiny. All men want happiness, and all philosophers seek the way to it, but without divine aid all fail: “Thou has made us for Thyself, and our heart is restless until it rest in Thee”—this famous exclamation from [Augustine’s]...Confessions is the exclamation of a tormented soul weary of mere thought, weary of autonomy, yearning for the sheltering security found in dependence on higher powers. When Augustine speaks of understanding or reason, these words have a religious admixture: philosophy to him is touched by the divine.[5]

Augustine’s dictum stands the…method of classical philosophizing on its head: God, who to the ancients was the result of thought, now becomes its presupposition. Faith is not the reward of understanding; understanding is the reward of faith. Man may search for the explanation of his situation by his humble reason; he may even try to order his moral conduct through the understanding. But the explanation for the human condition is a myth—the Fall; the guide to his salvation is a supernatural being—Jesus Christ; the proof text for the primacy of faith over reason is a divinely inspired book—the Bible; and the interpreter of this Book is an infallible authority—the Church. All four testify to the collapse of [ancient philosophers’] confidence in man’s unaided intellect.

Hence, nisi credideritis, non intelligetis: “unless you believe, you will not understand.”[6] This injunction is the center of Augustine’s doctrine on the relation of philosophy to theology, and through its enormous authority, it became the center of medieval speculation on the same subject, although the Scholastics, as the philosophers knew, provided intellect with much room for play....But faith [for Anselm] imposed on the believer the obligation to strive within his limited means to understand what he believes. True faith is a kind of love, the highest kind of love, and a true lover does not love ignorantly: like all other medieval philosophers, Anselm accepted Aristotle’s dictum that man naturally strives for knowledge.[7]

As Basil Willey points out, this conception of nature leads to views of science and motion which are unfamiliar to us today:

St. Thomas, following Aristotle, treats motion as a branch of metaphysics; he is interested in why it happens, not how. He discusses it in terms of ‘act’ and ‘potency’, quoting Aristotle’s definition of it as ‘the act of that which is in potentiality, as such.’ Motion exists, then because things in a state of potentiality seek to actualize themselves, or because they seek the place or direction which is proper to them....To every body in respect of its ‘form’, is ‘due’ a ‘proper place’, towards which it tends to move in a straight line.[8]

It is unnecessary to controvert theories of this kind as if they were ‘untrue’. Their ‘truth’ is not of the empirical kind; it consists in their being consistent with a certain world-view.[9]

Galileo typifies the direction of modern interests, in this instance, not in refuting St. Thomas, but in taking no notice of him. Motion might be all that the angelic doctor had declared it to be; Galileo nevertheless will drop weights from the top of a tower, and down inclined planes, to see how they behave. It is undeniable that the scholastic theory of motion informs us nothing of the manner in which bodies move in space and time, and this was precisely what Galileo wished to determine. He is concerned with quantities, not qualities; and his energy is thus devoted not to framing theories consistent with a rational scheme, but to measuring the speed of falling bodies in terms of time and space.[10]

In the scholastic doctrine of the heavenly bodies we have an illustration of the strange fact that a belief can be metaphysically ‘true’ (in the sense of ‘coherent’ or ‘consistent’) and yet empirically false, that is, not in correspondence with what we call a ‘state of affairs’. The received scholastic doctrine, for instance, taught that the heavenly bodies are unalterable and incorruptible. This belief seems to have rested on the assumption (fact, as it then appeared) that the motions of the heavenly bodies were circular.[11]

Thus the metaphysical theory of the heavens is confronted by comets, new stars, and sun-spots seen through the telescope; and Salviatus, speaking for Galileo himself, makes much of an alleged saying of Aristotle that we ought to prefer sense-evidence to logic.[12]

Galileo admitted that he knew nothing about the ultimate nature of the forces he was measuring; nothing about the cause of gravitation, or the origin of the Universe; he deemed it better, rather than to speculate on such high matters, ‘to pronounce that wise, ingenious and modest sentence, “I know it not”‘.[13]

In a letter to the Grand Duchess Christina Medici in 1615, which could serve as a marker of the difference between the Medieval and the Early Modern periods, Galileo says:

…I think that in discussion of physical problems we ought to begin not from the authority of scriptural passages, but from sense-experiences and necessary demonstrations; for the holy Bible and the phenomena of nature proceed alike from the divine Word, the former as the dictate of the Holy Ghost and the latter as the observant executrix of God’s commands. It is necessary for the Bible, in order to be accommodated to the understanding of every man, to speak many things which appear to differ from the absolute truth so far as the bare meaning of the words is concerned. But Nature, on the other hand, is inexorable and immutable; she never transgresses the laws imposed upon her, or cares a whit whether her abstruse reasons and methods of operation are understandable to men.[14]

Whereas theologians at Padua could have refused to look through Galileo’s telescope at the satellites of Jupiter because they knew it could not have any (that would conflict with theological premises), Galileo looked—the difference here is the presence or absence of an empirical spirit! Of course, the theologians of Padua had the authority of the Bible to rest upon—and geocentrism is deeply entrenched in the Biblical view: on the first day, according to it the deity created the Earth, and it was not until day four that the sun, moon, and other stars were created.[15] Clearly, defenders of geocentrism contend, the Earth can not be said to circle something whose existence is subsequent to its own existence. Surprisingly (to some), today’s internet has many sites which defend geocentrism. For example, Gerardus D. Bouw maintains that:

to hear tell, geocentrism, the ancient doctrine that the earth is fixed motionless at the center of the universe, died over four centuries ago. At that time Nicolaus Copernicus…a Polish canon who dabbled in astrology, claimed that the sun and not the earth was at the center of the universe. His idea is known as heliocentrism. It took a hundred years for heliocentrism to become the dominant opinion, and it did so with a complete lack of evidence in its favor.[16]

And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hastened not to go down about a whole day.

Here the Moderator of Scripture, the Holy Ghost Himself, endorses the daily movement of the sun and moon. After all, God could just as well have written: “and the earth stopped turning, so that the sun appeared to stand still, and the moon seemed to stay….” The wording would be no more “confusing” to the reader than anything in Job chapters 38 through 41….

….The Copernican Revolution, as this change of view is called, was not just a revolution in astronomy, but it also spread into politics and theology. In particular, it set the stage for the development of Bible criticism. After all, if God cannot be taken literally when He writes of “the rising of the sun,” then how can He be taken literally in writing of “the rising of the Son?”[17]

Skipping very lightly here, in addition to the rise of a new scientific orientation, the following additional “factors” need to be mentioned as we struggle to understand the breadth of the transition from the Medieval to the Early Modern world-view:

the Reformation and the Counter-Reformation: whereas Europe was Catholic throughout the Medieval period, a variety of circumstances lead to the broader Christian Early Modern period, and the emergence of broader literacy and vernacular versions of The Bible contributed significantly to this and to the rise of Biblical Criticism (the critical study of this work).

the rise of the nation-state: just as the hold of The Church was loosened, a new form of civil state emerged, and while there were many contributing factors, including the rise of cities, the new economic systems and mechanisms, the ability to utilize new scientific advances for warfare,

the discovery and exploitation of the New World: the discovery of new peoples (and renewed contact with the Orient) led to questions as to how these peoples fit into the Biblical world-view, and the economic opportunities (and the competition amongst differing nation-states for the new wealth and opportunities) provided many heretofore unheard of opportunities for individuals to amass wealth and power.

While these factors did not happen all at once, the combination of phenomena had an immense effect—one which we still feel today. What is the cumulative effect? I would sum it up as follows: insecurity, a desire for certainty (or authority), and a “faith” in individual abilities which somehow had to be rendered compatible with recognition of our fallibility.

In short, the stability, security, teleology, and certainty of the Medieval period were lost. This is the lament which is contained in the poetic reference earlier from John Donne. The rediscovery of Greek skeptical texts facilitated the development of modern skepticism. The Greek skeptics began with the ordinary distinction between knowledge and belief, and questioned whether we can offer any evidence which would lift claims which go beyond immediate experience from the latter category to the former one. They recommended a “suspension of belief”—if we are really without justification for our knowledge claims, we should not make them. Of course, the problem of justifying a standard of knowledge, of reality, or of morality did not arise as long as there was an unchallenged criterion. But in an age of intellectual revolution, of course, this was just the problem.

While there is much more to be said about the Medieval worldview, this will have to suffice. By the time Descartes is writing his Meditations, the Medieval view has lost much of its authority, and Descartes wanted to address an underlying skepticism which had become prominent--his goal was to clarify how human knowledge can be attained without the Medieval appeal to faith. When the foundations of our knowledge claims are unclear some philosophic work is necessary. Descartes undertakes the project of trying to find a firm and rational foundation for our knowledge claims--ironically one may claim that his view (and those of many of his compatriots is characterized by an immense “faith” in our ability to rationally uncover universal and general truths about the world. The new methodology of the empirical sciences was still under development in Descartes’ time however.

To achieve his goal Descartes’ must clarify the nature of justification. The area of philosophy called epistemology is especially concerned with the justifiability of our knowledge claims. In his Theaetetus Plato approaches the question of justification by asking “How we can tell whether we are dreaming or awake?” Remember that we rarely take “dream reports” as indicative of the true character of reality, while we far more frequently (but, of course, not always) take “awakened reports” as indicative of true states of affairs. The “dreaming” question, like all philosophical questions seems trivial, yet its deceptive simplicity belies the complexity which arises as one tries to answer it. Since we base most of our knowledge claims upon our sensory experience, if we can not tell whether our experiences are the fluff of dreams or the reports of the senses when we are awake, it seems that the experiences we rely upon may not be very reliable ones. No one, for example, would write his or her chemistry lab reports on the basis of last night’s dreams.

Well, how do we tell whether we are awake or asleep? If we can’t tell which state we are in, then can we place any reliability, credence, or worth in the reports?

Descartes agrees with Galileo that the “book of nature” is written in the language of mathematics—he believes the world was created according to mathematical formulae. His ability to hook together geometry and algebra reinforced this view. Central to his methodology is the strategy of beating the skeptics at their own game: his procedure is to doubt everything tinged with any “possibility of doubt” until he finds something which absolutely can not be doubted. He believes he can show that there is one claim which legitimately has this “highest” degree of certainty—his famous “I think, therefore I am,” or “cogito, ergo sum” argument, is to give us this level of certainty. There are several different senses of certainty (psychological certainty, logical certainty, and metaphysical certainty), and it is the latter which Descartes wants.[18]

With this claim Descartes will have a foundation upon which other knowledge claims may rest securely. Descartes wants to do more than refute skepticism however. He wants to show that the foundation which he “uncovers” is one which can be built upon, and this means he must get beyond subjectivity. Here his proof of the existence of a deity comes in—the argument he develops for the existence of an all-powerful, all-knowing, and benevolent deity provides him with the intellectual tool to move with certainty beyond knowledge of subjectivity.

Thus far this introduction to has covered only the “epistemological” aspects of Descartes’ thought, and it is already too long. The Meditations are as well-known and important for their “metaphysical” content as they are for their epistemological however, and we need to understand this before we look at the text. The general introductory story regarding Descartes’ metaphysics maintains that he offers a “dualistic metaphysic” which offers a picture of reality as bifurcated into two distinct categories of “things:” the mental and the physical.

To see the difference between these two categories of reality, begin by considering your “visual field” (the images you experience when you pay attention to your visual experience.[19] Concentrating on this “field,” try and answer the question “Where, in physical space, does this visual field reside?” Is it to be located in the brain?

Descartes holds that “physical things” all have one central characteristic: they are extended (or have some shape or other). While they can change their shapes (surely this is what we want to do when we visit our health clubs), they always have some shape or other. According to Descartes, however, “mental things” are not correctly characterized as having a shape. Instead, they are characterized as having “experiences.” Descartes holds that the mental and physical are distinct categories of things, and any thing (or, more strictly speaking, any created thing) must be one or the other (but not both).

This “dualistic picture” is right as far as it goes, but Descartes actually holds a more complex metaphysical picture. In addition to physical and mental substances or things, there is also a deity according to him. Strictly speaking, this “thing” is a mind, but it is significantly different from the sorts of mental substances which we are: it is infinite, and it is not dependent upon anything else.[20]

Mention of Descartes’ deity, however, seems to take us right back to the “picture” of the world offered by the Medieval world-view! It is important to note, however, that while he was a Catholic, the deity he discusses in the Meditations is better seen as a “god of the philosophers”[21]—this deity fulfills a particular role, and this role is what is important not any “personalistic” characteristics of the deity. For Descartes, the deity will provide a causal and explanatory terminus (and end for all questions of causation and justification), but this deity will be bereft of most of the medieval adornments.

It is also important to note that from the “modern” view-point of Descartes, the most appropriate way to approach (one almost wants to say “worship”) this deity is via reason—the goal is to come to know (rather than to worship) this “thing” and to try to know reality as this deity knows it. Such knowledge, it should be clear, is not to be developed by examining texts or consulting religious or scriptural authorities. Instead, it is to be had by rationally examining the “book of nature.” To see this clearly, however, we must turn to the text itself.

But if we are to understand his view of doubt, knowledge, the world, and his deity, we must work through his text carefully.

Notes: [click on note number to return to the text for the note]

[1] Cited by Toulmin on pp. 341-342 of his “The Recovery of Practical Philosophy,” The American Scholar v. 57 (1988), pp. 337-352.

[2] Cf., Arthur Lovejoy, The Great Chain of Being (Cambridge: Harvard U.P., 1936).

[3] Teleological explanations occur when past and present events are explained in terms of future events (they are “goal-oriented” explanations). They are often contrasted with mechanical explanations which hold that present and future events are to be explained in terms of past mechanical events and their consequences. The contrast is well-stated by Wilber Long in his entry under “teleology” in Dictionary of Philosophy, ed. Dagobert Runes (N.Y.: Philosophical Library, 1960), p. 315.

[4] Christian “apologists” were theologians who endeavored to offer rational arguments and proofs for Christianity.

[5] Peter Gay, The Enlightenment: An Interpretation: The Rise of Modern Paganism (N.Y.: W.W. Norton, 1966), p. 230. Emphasis added to passage twice.

[6] Gay’s footnote here reads: “this much-quoted passage is from the Septuagint version of the Bible, from Isaiah, VII, 9. All other versions translate the Hebrew differently. The King James Version has, “if you will not believe, surely ye shall not be established.” The Septuagint is an ancient Greek version of the Old Testament Scriptures that was made by between seventy and seventy-two translators between 208 and 130 B.C.E. Emphasis is added to the cited passage.

[7] Ibid., pp. 230-231.

[8] Basil Willey, The Seventeenth Century Background (New York: Columbia U.P., 1967), p. 16.

[9] Ibid., p. 17.

[10] Ibid.

[11] Ibid., p. 18.

[12] Ibid., p. 20.

[13] Ibid., p. 21.

[14] Galileo Galilei, “Letter to the Grand Duchess Christina” [1615], trans. Stillman Drake, in The Philosophy of the 16^th and 17^th Centuries, ed. Richard H. Popkin (New York: Free Press, 1966), p. 62.

[15] The Bible, Genesis I, 1-20.

[16] Gerardus Bouw, “Why Geocentricity?”, http://www.geocentricity.com/geocentricity/whygeo.html, last modified May 7, 2001, and accessed on May 5, 2011.

[17] Ibid.

[18] “Psychological” certainty would be where a specific individual finds herself unable to raise doubts (because of her psychological constitution, or her deeply felt convictions, or her predispositions, etc.), for example, she might be certain that her significant other was faithful to her. “Logical” certainty would be where no individual is able to raise valid doubts (because logic rules them out), for example, regarding the claim that there are no married bachelors (because bachelors are unmarried males of the age of consent). “Metaphysical” certainty would be where no doubts whatsoever could be raised (where error is absolutely inconceivable.

[19] I will not be as careful as I should be in distinguishing between “experiences” and “ideas.” There are translators of Descartes who take his talk of mentality to be talk of experience generically (all “contents of consciousness”), while others point out that he is primarily concerned with our “ideas” (in the sense of “propositions”). While I think Descartes himself is sometimes unclear on this issue, I believe that he is primarily concerned with our “ideas” in the latter sense and with trying to ensure that they are true. Ultimately, of course, if he is concerned with developing a deductive structure to ensure the justification of his claims, it must be propositions which he is concerned with. A proposition is a sentence which is capable of being true or false (thus, commands and questions are not such).

[20] Ultimately, Descartes’ definition of ‘substance’ is that it is something which is not dependent upon anything else, and, given his views of divine creation, it follows that both [finite] ‘physical substance’ and [finite] ‘mental substance’ are oxymorons.

[21] For clarification of the distinction between the sort of deity discussed by philosophers and the deity as many conceive it cf. Anthony Kenny, The God of the Philosophers (Oxford: Oxford U.P., 1979). As we will see, Descartes discussion of his deity will sometimes provide a possible significant check upon his commitment to reason, and, at times, it will appear he has more in common with Augustine than with Galileo. Cf., my “A Brief Note on Descartes, Eternal Truths, and Rationality.”