Lectures 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” which you were taught in High School gets its name from him. He also did important work in the field of optics, and his Meditations on First Philosophy was published in 1641.

To put his philosophy in perspective we should note that as philosophers seek to clarify our concepts and viewpoints one of the problems they regularly encounter is the question 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 their 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, can we place any reliability, credence, or worth in the reports?

When the foundations of our knowledge claims are unclear some philosophic work is necessary. Descartes undertakes the project of trying to find a firm foundation for our knowledge claims. He does this because, in part, of the times in which he lives.

As we have seen, the Medieval period marked a significant departure from the Ancient one—thinkers like St. Anselm maintained that reason must take its cues from certain truths of faith. They held that philosophy is important as we try to come to understand what we antecedently believe (through faith). Ancient thinkers like Plato, by contrast, held that we should believe what we can rationally establish. Thus contrast Plato’s Socrates’ statement that “I am the kind of man who listens only to the argument that on reflection seems best to me” [Crito, 46b] with Anselm’s desire to come to understand what he antecedently believes. The Modern period (which we have already encountered with our reading of selections from Hobbes’ Leviathan) is characterized by an immense “faith” in our ability to rationally uncover universal and general truths about the world—it is, then a return to the philosophical view of the Ancients. As such a return, however, it is conditioned by the loss of both the feelings of security and of certainty which the Medieval period provided with its “faith-based” foundation. This loss did not occur because of the development of a clear-cut and widely-accepted “replacement” methodology however. The methodology of the new empirical sciences was still under development in Descartes’ time.

Thus skepticism and relativism loomed large. With the Renaissance, the rediscovery of the Greek skeptical texts encouraged this feeling of insecurity while eating away at the faith which grounded the Medieval period. It became clear that there were “high” cultures which were not grounded on the sort of faith and belief which were at the core of Medieval civilization. Obviously the problem of justifying a standard of knowledge (or of reality, or of morality) did not arise as long as there was an unchallenged criterion, but in an age of intellectual revolution these problems are thrust into prominence.

Descartes agrees with Galileo that the “book of nature” is written in the language of mathematics—he believes the world was created according to some “simple” mathematical formulae. His ability to hook together geometry and algebra reinforced this view. He wants to firmly ground his knowledge claims, and thus wants to establish that they are truly beyond doubt—that they are certain. There are several different senses of certainty (psychological certainty, logical certainty, and metaphysical certainty), and it is the latter which Descartes wants.

Descartes believes he can show that there is one claim which legitimately has this degree of surety—his cogito argument (his famous “I think, therefore I am”—or “cogito, ergo sum”) gives us this level of certainty. He will go on to justify much of human knowledge (including knowledge of a deity) and to develop a dualistic metaphysics. He would beat the skeptics at their own game: his procedure is to doubt everything tinged with any doubt (to reject everything which he can) until he finds something which can not be doubted. With this claim he 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 provide him with the intellectual tool to move with certainty beyond knowledge of subjectivity.

Thus far this introduction to has covered only the “epistemological”[1] aspects of Descartes’ thought, and it is already too long. The Meditations are as well-known and important for their “metaphysical”[2] content as they are for their epistemological content 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. 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 experience. Descartes holds that the mental and physical are distinct categories of things, and any thing must be one or the other (but not both).

This “dualistic picture” of Descartes’ metaphysics is right as far as it goes, but he actually holds that there are three distinct kinds of things. In addition to physical objects (also called “extended things” by him), and mental objects (also called “minds,” or “selves” by him), there is also a deity. Strictly speaking, this “thing” is not physical or mental (at least not in the senses discussed thus far). The minds and objects discussed thus far are all finite in nature, and the deity which he discusses is infinite.

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“[3]—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 any inquiry—including one about a deity it to follow the a chain of deductive reasoning. The goal is to come to know things, and 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.

Type of doubt—he recommends that we doubt whatever is not indubitable or entirely certain—even what is only slightly tinged or possibly tinged! It is general—he doesn’t doubt each proposition but, rather, doubts them in groups.

-But, perhaps, sometimes the senses don’t—when we are “close” to the object, etc.

The dreaming argument: But I do dream: “I have been deceived in sleep by similar perceptions.”

-534 Surely “simples” are true whether one is awake or dreaming? That is, whether my experiences are dreaming or awakened ones, surely the “simple components” of the experiences (those out of which the “complexes” are formed) provide me with a solid (and valid) base of knowledge claims. Can’t I suppose that dream images still represent the world somewhat? That is, may I suppose that there are simples like the elements in a picture (that the structure of the painting may be all wrong, as it were, but that the elements in it actually correspond or represent?).

“Be that as it may, there is fixed in my mind a certain opinion of long standing, namely that there exists a God who is able to do anything and by whom I, such as I am, have been created. How do I know that He did not bring it about that there is no earth at all, no heavens, no extended thing, no shape, no size, no place, and yet bring it about that all these things appear to me to exist precisely as they do now? Moreover, since I judge that others sometimes make mistakes in matters that they believe they know most perfectly, may I not, in like fashion, be deceived every time I add two and three or count the sides of a square, or perform an even simpler operation, if that can be imagined?”

-That is, how do I know that any claims about the “simple” elements of experience are valid? I will suppose an “evil genius” who is at once exceedingly potent and deceitful, and who employs all his artifice to deceive me.

-What of Jorge Luis Borges’ “The Circular Ruins,”[5] or Lewis Carroll’s Through the Looking-Glass?[6]

536 Sum res cogitans: but I do not yet know with sufficient clearness what I am, though assured that I am.

--A “rational animal”—this leaves us with two questions to answer (“What is rationality?” and “What is an animal?”) and we have no way of getting started here.

--Body: Can I affirm that I possess any one of the attributes of which I have lately spoken as belonging to the nature of body? After attentively considering them in my own mind, I find none of them that can properly be said to belong to myself.

536-537 My knowledge that I am a thinking thing is not dependent on things which are not certain.

-Memory and occurrent conception of the self: Christopher Nolen’s movie Memento [2000]—without short-term memory, we get a very different “self!” Of course there is also “long-term” memory, and other sorts! Moreover, does memory entail any sort of certainty?

-Personal identity and Theseus’ ship—my “updated case would have one imagine a ship (Theseus’) which is rebuilt plank by plank (with the original planks saved and then reassembled according to the original plan. The question is: “Which of the resultant ships is Theseus’ ship?”

537 Nonetheless, Descartes concludes that he knows he is an enduring thing—a substance:

-“For it is so obvious that it is I who doubt, I who understand, and I who will, that there is nothing by which it could be explained more clearly. But indeed it is also the same “I” who imagines; for although perhaps, as I supposed before, absolutely noting that I imagined is true, still the very power of imagining really does exist, and constitutes a part of my thought. Finally, it is this same “I” who senses or who is cognizant of bodily things as if through the senses….”

I readily discover that there is nothing more easily or clearly apprehended than my own mind—we know our minds better than we know our bodies.

Building a bridge from the “subjective world” to the “objective world.”

He seeks the identification of a characteristic of some ideas which assures they represent.

Dark Pool Analogy: if you are swimming alone in a dark pool and you feel something brush your leg, it is natural to reach the (alarming) conclusion that you are not alone.

The “Anthropology Example:”[7] find a tribe which has a drawing of a complex machine, or an advanced metal object:

tells us something about the level of development of the tribe. They must have such machines (or the imagination necessary to conceive of them), or the ability to make, trade, or otherwise acquire such objects.

-formal reality of an idea—a “lower level” than the formal reality of minds, since ideas are dependent upon minds);

-objective reality of an idea—the referential content (or representational capacity) of the idea.

ex nihilo nihil fit[8] (Descartes believes it and the principle are equivalent.

Aristotelian analysis of causation: the efficient cause explains the existence of a thing, while the formal cause explains the nature of that thing.

Together the causal principle, the idea of the degrees of reality of ideas (objective reality), the idea of a deity and Descartes’ knowledge that he does not have the power to cause this idea yield the proof that this deity exists!

539 Those modes of consciousness exist in me—substance vs. attribute, and attribute vs. mode.

There is nothing that gives me assurance of the cogito’s truth except the clear and distinct perception of what I affirm. Can I generalize this finding (can I say that all that I perceive clearly and distinctly is true)?

What did I clearly and distinctly “perceive” before? The tendency to believe that besides the ideas, there were “external things” which these ideas represented (the problem of representationalism).

539-540 Conflict between the “metaphysical doubt,” on the one hand, and the “cogito” and “clear and distinct ideas,” on the other. Here we encounter Descartes’ “epistemological schizophrenia.”

Ideas are generally considered to be innate, adventitious (caused from without), or factitious (I cause them).

-540-541 Could the representational claim of my ideas be grounded in the fact that I am taught the representational nature of my ideas by nature? Here, “...all I have in mind is that I am driven by a spontaneous impulse to believe this, and not that some light of nature is showing me that it is true. These are two very different things. For whatever is shown me by this light of nature, for example that from the fact that I doubt, it follows that I am, and the like, cannot in any way be doubtful. This owing to the fact that there can be no other faculty that I can trust as much as this light and which could teach that these things are not true. But as far as natural impulses are concerned....”

-541 Could the representational claim be justified by the fact that various of my ideas are not dependent upon my will? “I may have powers I don’t know of....”

-Moreover, even if the ideas “proceed from” objects, “...it is not a necessary consequence that they must be like them.”

Dependency of attributes/modes on substances; dependence of finite upon infinite substance: Everything which exists has a cause, or ex nihilo nihil fit.

-Efficient and total cause—idea that the cause must be “explanatory” as well as “efficient”—it must not only have the power, but also the reason, to bring about the effect:

-Cause of idea must be at least real enough to cause this sort of idea (e.g., one which has this sort of object—objective reality=representative capacity).

-Formal (actual) reality—nonideational reality (reality which is not representative but, rather, actual). Our ideas have formal reality as modes of thought—as such, of course, they are neither true nor false however. It is their objective reality which is in question, then, here.

--Anthropology example: Bernard Williams notes that if we find a primitive tribe which has a picture of a complex machine, this tells us something about the level of development of the tribe. They must have such machines or the imagination necessary to conceive of them. Higher order understanding exhibited by the picture betokens a higher order of cultural development.[9]

“...in order that an idea may contain this objective reality rather than that, it must doubtless derive it from some cause in which is found at least as much formal reality as the idea contains objective.”

542 If some idea is such that I can’t cause it—then I am not alone. Dark Pool Analogy: if you are swimming alone in a dark pool and you feel something brush your leg, it is natural to reach the (alarming) conclusion that you are not alone.

543 There remains, then, the idea of god. The proof that I am not the cause of it.

-543-544 Perhaps I am god? No, not even potentially! (Were I so, I would have made me different—no doubts!).

-544-545 Could I, and my idea, have been created by a lesser deity—still need god to cause this positive idea!

-A god—why not many? Not a committee because of the simplicity and relatedness of the conceptions. [A camel is a horse made by a committee].

545 This deity can not be a deceiver. “For it is manifest by the light of nature that fraud and deception depend on some defect.”

-Note that here, again, we have and appeal to the “light of nature”—what legitimates such an appeal?[10]

This proof presupposes his cogito (his “proof of himself”), as well as his ideas (see below), and his “knowledge” of his “finitude” (especially his character as a doubter).

It presupposes the existence of the idea of an all-powerful, all-knowing, and all-good infinite (and perfect) being.

-Clarify how this principle applies to ideas (formal vs.·representative reality [or objective reality]).

Anselm is concerned to prove necessary existence, while Descartes just wants to prove existence. The difference between ontological and causal proofs here is a difference in the philosophers’ purposes, their types of premises and arguments, and in their conclusions.

Anselm begins with “essences” and metaphysical truths, while Descartes begins with doubt and self.

Anselm begins with faith which he tries to understand, Descartes wants to establish the existence of the deity from human understanding alone to provide a ground for “science” and human knowledge of the world.

Gilbert Ryle: “I must say a little about the quite general argument from the notorious limitations and fallibility of our senses to the impossibility of our getting to know anything at all by looking, listening and touching.

A country which had no coinage would offer no scope to counterfeiters. There would be nothing for them to manufacture or pass counterfeits of. They could, if they wished, manufacture and give away decorated disks of brass or lead, which the public might be pleased to get. But these would not be false coins. There can be false coins only where there are coins made of the proper materials by the proper authorities.

In a country where there is a coinage, false coins can be manufactured and passed; and the counterfeiting might be so efficient that an ordinary citizen, unable to tell which were false and which were genuine coins, might become suspicious of the genuineness of any particular coin that he received. But however general his suspicions might be, there remains one proposition which he cannot entertain, the proposition, namely, that it is possible that all coins are counterfeits. For there must be an answer to the question ‘Counterfeits of what?’”[12]

J.L. Austin “...it is important to remember that talk of deception only makes sense against a background of general non-deception. (You can’t fool all of the people all of the time.) It must be possible to recognize a case of deception by checking the odd cases against the more normal ones.”[13]

G.E. Moore: “...can he [Descartes] consistently combine this proposition that he knows that dreams have occurred, with his conclusion that he does not know that he is not dreaming? Can anybody possibly know that dreams have occurred, if, at the time, he does not himself know that he is not dreaming? If he is dreaming, it may be that he is only dreaming that dreams have occurred; and if he does not know that he is not dreaming, can he possibly know that he is not only dreaming that dreams have occurred? Can he possibly know therefore that dreams have occurred? I do not think that he can; and therefore I think that anyone who uses this premise and also asserts the conclusion that nobody ever knows that he is not dreaming, is guilty of an inconsistency.”[14]

(B). In his Tragic Sense of Life, Miguel de Unamuno offers the following critique of Descartes:

the defect of Descartes’...[argument] lies in his resolution to empty himself of himself, of Descartes, of the real man, the man of flesh and bone, the man who does not want to die, in order that he might be a mere thinker—that is, an abstraction. But the real man returned and thrust himself into his philosophy....

The truth is sum, ergo cogito—I am, therefore I think, although not everything that is thinks. Is not conscious thinking above all consciousness of being? Is pure thought possible, without consciousness of self, without personality?[15]

(D). What of his right to talk about a continuing substance—the problem of multiple selves.

Notes: (click on note number to return to the text for the note)

[1] That is, the elements dealing with his “theory of knowledge”—his views on knowledge, justification, and certainty.

[2] That is, for his views about the fundamental nature of (or characteristics of) reality.

[3] 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).

[4] The notes are to Donald A. Cress’ translation of Descartes Meditations on First Philosophy [1641] which was published in 1993, as reproduced in Classics of Western Philosophy (seventh edition), ed. Steven Cahn (Belmont: Wadsworth, 2012), pp. 533-546.

[5] Cf., Jorge Luis Borges, “The Circular Ruins,” in The Light Fantastic, ed. Harry Harrison (N.Y.: Scribners, 1971).

[6] Cf., “Chapter IV. Tweedledum and Tweedledee,” in Louis Carroll, Through The Looking Glass [1871], in The Annotated Alice: Alice’s Adventures in Wonderland and Through the Looking Glass, ed. Martin Gardner (N.Y.: Meridian, 1963), pp. 229-244.

[7] This example is discussed in detail in Bernard Williams, in his Descartes: The Project of Pure Enquiry (Harmonsworth: Penguin, 1978), pp. 138-142.

[8] That is, “nothing is created from nothing.”

[9] Cf., Bernard Williams, Descartes: The Project of Pure Enquiry, op. cit., p. 139.

[10] Cf., John Morris, “Descartes’ Natural Light,” Journal of the History of Philosophy v. 11 (1973), pp. 169-187.

[11] Cf., Jay Rosenberg, The Practice of Philosophy (Englewood Cliffs: Prentice Hall, 1984), pp. 15-17.

[12] Gilbert Ryle, Dilemmas (Cambridge: Cambridge U.P., 1960), pp. 94-95.

[13] J.L. Austin, Sense and Sensibilia (Oxford: Oxford U.P., 1962), p. 11. Cf., also Anthony Kenny, Descartes: A Study of His Philosophy (New York: Random House, 1968), p. 25.

[14] G.E. Moore, “Certainty,” in his Philosophical Papers (London George Allen & Unwin, 1959), pp. 227-251, p. 249. Cf., “Can I Know That I Am Not Dreaming?,” by D. Blumenfeld and J.B. Blumenfeld, in Descartes: Critical and Interpretive Essays, ed. Michael Hooker (Baltimore: Johns Hopkins U.P., 1978), pp. 234-235.

[15] Miguel de Unamuno, Tragic Sense of Life, trans. C.J. Flitch (N.Y.: Macmillan, 1921), p. 34.