Unit One: What is philosophy?

Part B: Thinking Which Seeks a Critical Foundation for Knowledge

In Part A we saw how philosophical thinking involves a break with purely calculative thinking. For Heidegger, this break opens the door to the possibility of meditative thinking, an essential element of philosophical thinking he argues. For Heidegger meditative thinking is concerned with searching out the horizons of meaning in the world. Is it God who forms the basis for meaning in the world and in our lives? Is it the existence of objective ethical ideals? Is it we ourselves as individuals who create the only meaning there is--as the German philosopher, Friedrich Nietzsche argues? Or is meaning, positive or negative, largely, if not exclusively, a matter of the way our history conditions who we are? This is what Heidegger thinks. While we are free beings, Heidegger thinks, the size and shape of the field of freedom's meaning, its possibilities, is very much a matter of the horizons of our history. Thus, that we live in an age when technology has developed to the degree it has on the one hand extends the ways in which life can be meaningful. But on the other hand, the dominance of calculative thinking in such an age, draws a curtain over the negative meaning or significance of much technological development, obscuring other orders of meaning.

Other philosophers, while agreeing that thinking which is fully human goes beyond calculative thinking, argue that philosophical thinking is marked especially by its critical character together with an effort to discover the foundations for knowledge of the world and of ourselves. Maybe we can know a basis of meaning or value in the world, maybe not. In any case, there are ways in which people claim to know the world, even if they doubt we can know that life is meaningful or that some things are valuable in themselves. Scientists, for example, claim to give us knowledge of the world. But Einstein's famous law, E = mc², appears to have nothing to do with questions about meaning or value. Foremost among such philosophers was RÃ(tm)nÃ(c) Descartes and he undertook this combined project of criticism and search for foundations in a set of meditations. (We should be careful about equating Descartes's "meditation" with what Heidegger means by "meditative thinking." There are similarities, as we shall see, but also important differences.)

For Descartes, philosophical meditation is concerned with purifying our thinking from error and unexamined assumptions (the cause of error) and rebuilding it as a structure of true belief resting on a secure foundation. What element in thought has the power to carry out this purification and rebuilding? It is the power of reason in thought which enables thought to purify itself of error and establish knowledge on firm foundations. The critical side of philosophical thinking is a matter of discovering the beliefs (or types of beliefs) which may be doubted, that is, which do not show themselves to be absolutely certain. Criticism must be as radical as possible in this effort to purify thought. It must put into doubt beliefs in which we have the greatest confidence as long as any possibility remains, however apparently farfetched, that they may be mistaken. The other side of philosophical thinking, the positive side, is to determine if there is some belief which is indeed absolutely certain, impossible to doubt in the sense that reason would contradict itself in doubting this belief. Once in possession of something absolutely certain, reasoning thought can turn to rebuilding the house of belief on this firm foundation.

It is important to understand how radical Descartes's project is. He is often said to be the father of modern philosophy as being foremost and among the first to challenge the idea that knowledge is largely a matter of accepting traditional authorities such as the church or schools. (In Descartes's day the university was largely a place to become familiar with and appreciate the fine points of what was an accepted body of knowledge, a privilege reserved for few people.) A "modern" person is one who thinks for herself or himself, who takes nothing for true simply because others have said it to be true.

Several years have now elapsed since I first became aware that I had accepted, even from my youth, many false opinions for true, and that consequently what I afterward based on such principles was highly doubtful; and from that time I was convinced of the necessity of undertaking once in my life to rid myself of all the opinions I had adopted, and of commencing anew the work of building from the foundation, if I desired to establish a firm and abiding superstructure in the sciences. But as this enterprise appeared to me to be one of great magnitude, I waited until I had attained an age so mature as to leave me no hope that at any stage of life more advanced I should be better able to execute my design. On this account, I have delayed so long that I should henceforth consider I was doing wrong were I still to consume in deliberation any of the time that now remains for action. To-day, then, since I have opportunely freed my mind from all cares [and am happily disturbed by no passions], and since I am in the secure possession of leisure in a peaceable retirement, I will at length apply myself earnestly and freely to the general overthrow of all my former opinions.

But, to this end, it will not be necessary for me to show that the whole of these are false--a point, perhaps, which I shall never reach; but as even now my reason convinces me that I ought not the less carefully to withhold belief from what is not entirely certain and indubitable, than from what is manifestly false, it will be sufficient to justify the rejection of the whole if I shall find in each some ground for doubt. Nor for this purpose will it be necessary even to deal with each belief individually, which would be truly an endless labor; but, as the removal from below of the foundation necessarily involves the downfall of the whole edifice, I will at once approach the criticism of the principles on which all my former beliefs rested.

Descartes begins to set forth the ways in which his present beliefs may be doubted. We have experiences in which our senses lead us astray, as when we attempt to identify some object which we see at a distance. Yet how could we possibly doubt the testimony of our senses with respect to the things which are within arm's reach? Are sight, hearing, touch, etc., absolutely reliable for objects so close at hand? Wouldn't it be insane to doubt our senses to that extreme point?

All that I have, up to this moment, accepted as possessed of the highest truth and certainty, I received either from or through the senses. I observed, however, that these sometimes misled us; and it is the part of prudence not to place absolute confidence in that by which we have even once been deceived.

But it may be said, perhaps, that, although the senses occasionally mislead us respecting minute objects, and such as are so far removed from us as to be beyond the reach of close observation, there are yet many other of their informations (presentations), of the truth of which it is manifestly impossible to doubt; as for example, that I am in this place, seated by the fire, clothed in a winter dressing gown, that I hold in my hands this piece of paper, with other intimations of the same nature. But how could I deny that I possess these hands and this body, and withal escape being classed with persons in a state of insanity, whose brains are so disordered and clouded by dark bilious vapors as to cause them pertinaciously to assert that they are monarchs when they are in the greatest poverty; or clothed [in gold] and purple when destitute of any covering; or that their head is made of clay, their body of glass, or that they are gourds? I should certainly be not less insane than they, were I to regulate my procedure according to examples so extravagant.

Maybe, all those things which I think I see and hear so near at hand are only objects in my dream. Sometimes we have very vivid dreams. So if my senses are not deceiving me, perhaps I am mistaken about the things around me because they don't really exist at all, because they are only products of my dreaming imagination. This may sound like a farfetched basis for doubt. But all that Descartes requires is the possibility of deception on the basis of the possibility of dreaming. Sometimes we say, "Pinch me so I know I'm not dreaming." What would Descartes say about the painful pinch as a guarantee of being awake?

Though this be true, I must nevertheless here consider that I am a man, and that, consequently, I am in the habit of sleeping, and representing to myself in dreams those same things, or even sometimes others less probable, which the insane think are presented to them in their waking moments. How often have I dreamt that I was in these familiar circumstances, that I was dressed, and occupied this place by the fire, when I was lying undressed in bed? At the present moment, however, I certainly look upon this paper with eyes wide awake; the head which I now move is not asleep; I extend this hand consciously and with express purpose, and I perceive it; the occurrences in sleep are not so distinct as all this. But I cannot forget that, at other times I have been deceived in sleep by similar illusions; and, attentively considering those cases, I perceive so clearly that there exist no certain marks by which the state of waking can ever be distinguished from sleep, that I feel greatly astonished; and in amazement I almost persuade myself that I am now dreaming.

Let us suppose, then, that we are dreaming, and that all these particulars--namely, the opening of the eyes, the motion of the head, the forth- putting of the hands--are merely illusions; and even that we really possess neither an entire body nor hands such as we see. Nevertheless it must be admitted at least that the objects which appear to us in sleep are, as it were, painted representations which could not have been formed unless in the likeness of realities; and, therefore, that those general objects, at all events, namely, eyes, a head, hands, and an entire body, are not simply imaginary, but really existent. For, in truth, painters themselves, even when they study to represent sirens and satyrs by forms the most fantastic and extraordinary, cannot bestow upon them natures absolutely new, but can only make a certain medley of the members of different animals; or if they chance to imagine something so novel that nothing at all similar has ever been seen before, and such as is, therefore, purely fictitious and absolutely false, it is at least certain that the colors of which this is composed are real. And on the same principle, although these general objects, viz. [a body], eyes, a head, hands, and the like, be imaginary, we are nevertheless absolutely necessitated to admit the reality at least of some other objects still more simple and universal than these, of which, just as of certain real colors, all those images of things, whether true and real, or false and fantastic, that are found in our consciousness (cogitatio),are formed. . . .

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So even if I am dreaming, my imagination isn't able to invent objects out of nothing. The (seeming) sensory quality of things, e.g. color, sound, taste and the (apparent) number are basic realities. Number is real--and all that goes with that, namely, the validity of mathematics, e.g. the certainty that 2 + 2 = 4. And my impression of sensory qualities, for example, the image of blueness I have when I close my eyes, refers to something real. Still, is it absolutely certain that 2 + 2 = 4? Isn't it possible that there is some god-like evil demon who is fooling me about these things? Think of the situation of ordinary people in the movie, Matrix. Are they dreaming? No, there is something like Descartes's evil demon who is responsible for virtually all of their experience and beliefs. They are mistaken with respect to just about everything. Does the matrix deceive them about such things as mathematics?

Nevertheless, the belief that there is a God who is all powerful, and who created me, such as I am, has, for a long time, obtained steady possession of my mind. How, then, do I know that he has not arranged that there should be neither earth, nor sky, nor any extended thing, nor figure, nor magnitude, nor place, providing at the same time, however, for [the rise in me of the perceptions of all these objects, and] the persuasion that these do not exist otherwise than as I perceive them ? And further, as I sometimes think that others are in error respecting matters of which they believe themselves to possess a perfect knowledge, how do I know that I am not also deceived each time I add together two and three, or number the sides of a square, or form some judgment still more simple, if more simple indeed can be imagined?

. . . [I] am constrained at last to avow that there is nothing of all that I formerly believed to be true of which it is impossible to doubt, and that not through thoughtlessness or levity, but from cogent and maturely considered reasons; so that henceforward, if I desire to discover anything certain, I ought not the less carefully to refrain from assenting to those same opinions than to what might be shown to be manifestly false.. . . .

At this point, if knowing depends upon having an absolutely certain foundation for belief, it looks as if we should all be skeptics; that is, we should give up believing that we can know anything at all. That is what Descartes's method of doubt seems thus far to show to be reasonable. Or would we have to know with certainty that we can't know anything with certainty to justify our skepticism? The paragraph below suggests that a person might know with certainty that nothing is certain. What is wrong with this idea? Is it really possible to know with certainty that nothing is certain? In any case, it is with this idea in mind that Descartes determines to press on with his meditation.

The Meditation of yesterday has filled my mind with so many doubts, that it is no longer in my power to forget them. Nor do I see, meanwhile, any principle on which they can be resolved; and, just as if I had fallen all of a sudden into very deep water, I am so greatly disconcerted as to be unable either to plant my feet firmly on the bottom or sustain myself by swimming on the surface. I will, nevertheless, make an effort, and try anew the same path on which I had entered yesterday, that is, proceed by casting aside all that admits of the slightest doubt, not less than if I had discovered it to be absolutely false; and I will continue always in this track until I shall find something that is certain, or at least, if I can do nothing more, until I shall know with certainty that there is nothing certain. Archimedes, that he might transport the entire globe from the place it occupied to another, demanded only a point that was firm and immovable; so, also, I shall be entitled to entertain the highest expectations, if I am fortunate enough to discover only one thing that is certain and indubitable.

I suppose, accordingly, that all the things which I see are false (fictitious); I believe that none of those objects which my fallacious memory represents ever existed; I suppose that I possess no senses; I believe that body, figure, extension, motion, and place are merely fictions of my mind. What is there, then, that can be esteemed true? Perhaps this only, that there is absolutely nothing certain.

So for all the reasons given thus far, it may be that all my beliefs about the reality of the world around me are false. Even the beliefs I have about my own body may be false. Do I even have a body? Maybe nothing of the world I think I know exists. Maybe I don't exist. Descartes thinks you can find some reason to doubt that you have a body. But can you doubt that you exist?

But how do I know that there is not something different altogether from the objects I have now enumerated, of which it is impossible to entertain the slightest doubt? Is there not a God, or some being, by whatever name I may designate him, who causes these thoughts to arise in my mind ? But why suppose such a being, for it may be I myself am capable of producing them? Am I, then, at least not something? But I before denied that I possessed senses or a body; I hesitate, however, for what follows from that? Am I so dependent on the body and the senses that without these I cannot exist? But I had the persuasion that there was absolutely nothing in the world, that there was no sky and no earth, neither minds nor bodies; was I not, therefore, at the same time, persuaded that I did not exist? Far from it; I assuredly existed, since I was persuaded. But there is I know not what being, who is possessed at once of the highest power and the deepest cunning, who is constantly employing all his ingenuity in deceiving me. Doubtless, then, I exist, since I am deceived; and, let him deceive me as he may, he can never bring it about that I am nothing, so long as I shall be conscious that I am something. So that it must, in fine, be maintained, all things being maturely and carefully considered, that this proposition (pronunciatum ) I am, I exist, is necessarily true each time it is expressed by me, or conceived in my mind.

So it appears that we don't have to be skeptics. There is something that each of us can know for certain when we try to doubt everything. If I doubt, I am thinking. And if I am thinking, I must exist. Cogito ergo sum. I think. Therefore, I exist. I can't doubt that I exist without, in that very thought or idea, contradicting myself. But there is a catch here. Perhaps we shouldn't go out and have a beer to celebrate just yet. What is the catch? See if you can find the answer in the paragraphs which follow.

But I do not yet know with sufficient clearness what I am, though assured that I am; and hence, in the next place, I must take care, lest perchance I inconsiderately substitute some other object in room of what is properly myself, and thus wander from truth, even in that knowledge ( cognition ) which I hold to be of all others the most certain and evident. For this reason, I will now consider anew what I formerly believed myself to be, before I entered on the present train of thought; and of my previous opinion I will retrench all that can in the least be invalidated by the grounds of doubt I have adduced, in order that there may at length remain nothing but what is certain and indubitable.

What then did I formerly think I was ? . . . In the first place, then, I thought that I possessed a countenance, hands, arms, and all the fabric of members that appears in a corpse, and which I called by the name of body. . . . By body I understand all that can be terminated by a certain figure; that can be comprised in a certain place, and so fill a certain space as therefrom to exclude every other body; that can be perceived either by touch, sight, hearing, taste, or smell; that can be moved in different ways, not indeed of itself, but by something foreign to it by which it is touched [and from which it receives the impression]; for the power of self-motion, as likewise that of perceiving and thinking, I held as by no means pertaining to the nature of body; on the contrary, I was somewhat astonished to find such faculties existing in some bodies.

But [as to myself, what can I now say that I am], since I suppose there exists an extremely powerful, and, if I may so speak, malignant being, whose whole endeavors are directed toward deceiving me ? Can I affirm that I possess any one of all those attributes of which I have lately spoken as belonging to the nature of body ? . . . I now admit nothing that is not necessarily true. I am therefore, precisely speaking, only a thinking thing, that is, a mind (mens sive animus), understanding, or reason, terms whose signification was before unknown to me. I am, however, a real thing, and really existent; but what thing? The answer was, a thinking thing.

Having found one thing that he can know with certainty, when he examines closely what he has established, Descartes sees that his meditation has a long way to go. It is one thing to know that you exist as a thinking thing, that is, as a mind. But it remains possible that this mind is filled with all sorts of mistaken beliefs about its having a body, about everything that the senses lead it to believe. It remains possible that this mind is a dreaming mind or that it is a mind deceived by evil forces, as in the Matrix. The main task that Descartes pursues in the rest of his meditations is to establish the reliability of his senses, when they are rightly used. There is one particularly well known step in his thinking. Descartes believes he can establish with certainty that God exists; and if such an all-powerful and good being exists, he would not let us be so deceived as was imagined when we supposed there might be an evil demon deceiving us. We will return later in the semester to what philosophers have thought about religious belief.

Heidegger also believes that philosophical thinking should be critical, that we should examine carefully the things we take to be true. In particular, we saw how he would have us be critical of our confidence in calculative thinking. But Heidegger did not think that we can establish a system of true beliefs based upon certain foundations and purified from error and assumption. Assumptions are the horizons of our beliefs. Imagine that you see a ship on the horizon and that you determine to travel to the horizon where that ship is located. What happens when you get there? You see the ship much better of course, but that you can do so depends upon there being another horizon in terms of which you can see what is directly before you. That horizon may be relatively clear or shaded in mist or coming darkness. But it is the essential background to seeing anything, and there is always another horizon beyond the one you are striving to see more clearly. It is only because we have beliefs which we simply accept that it is possible for us to have other beliefs which we hold on the basis of close examination and reasoned justification (which never amounts to absolute certainty). In the process of looking at these beliefs we may be led to criticize some of our assumptions. We can do this, however, only on the basis of simply accepting some other beliefs as the horizon of our critical examination. And on it goes. The impossibility of arriving at certain foundations does not leave us wandering in complete darkness. Imagine two sailors, one who has learned to navigate by studying the patterns in the stars, another who never pays attention to the stars and simply goes wherever the wind blows. He complains: Why do you look at the stars? You don't have any idea of why they move as they do. Even though the first sailor may have no idea why the stars move the way they do, she is able to navigate the seas, to set sail, to drop sail, to tack, etc. in order to arrive at a destination. She knows a great deal, even if she knows nothing for certain. The second sailor, a skeptic, isn't long for this world.

Still, maybe some things may be known for certain even if not absolutely certain. Isn't Descartes right that it is certain that when or as thinking, he exists? But this may not be something he knows absolutely or with purity in being certain. Perhaps there are horizons essential to existing as a thinking thing which are hidden from him by his method. Many philosophers would say that to exist as a thinking thing, as a mind, requires the existence of a brain or a brain-like physical structure. And that may not be something that can be known for certain. Thinking, even critical thinking, seems to be a very messy thing.

Appearance and Reality: Heidegger’s and Descartes’s Common Ground

There are many differences between Heidegger’s and Descartes’s conceptions of philosophical thinking. For instance, Descartes thinks that philosophical thought can not progress without finding something absolutely certain to serve as a foundation for knowledge. Heidegger, by contrast, holds that philosophical thinking, a reflection about meaning, must sustain itself in a field of uncertainty, uncovering a landscape of meaning that may look very different as one extends the conceptual horizons from which one views what this landscape offers to sight.

On one significant point, Heidegger and Descartes are in agreement, namely, that we begin to think philosophically when we begin to doubt our customary beliefs and manners of thinking. The world delivered by customary beliefs and ways of thinking is mere appearance, dreamlike. For Heidegger, reality, the truth of things, is hidden by the domination of the forces of calculative thinking. For Descartes, the world of common experience and thinking may turn out to be a dream-world unless, thinking in a different way, we can establish a basis for knowing it to be the real world.

In the history of western philosophy, the suspicion regarding common experience and ways of thinking begins with the philosophy of the ancient Greek, Plato. In one of his most famous philosophical works, The Republic, which deals with the question of the nature of justice, we find a myth or allegory that pictures this philosophical suspicion of the world of appearances. Since Plato, other pictures of the suspicion of appearances have been made. A recent one may be found in the film, The Matrix. You may recall that the film raises the possibility that our everyday view of the world is one created by a monstrous computer system. To see the world as it really is, Neo, the hero of the film, undertakes a quest for a way to restore reality to appearances. This quest involves a search for an understanding of the good which will empower him to sweep away the evil forces which divide appearances from the truth. The question of whether and how much an understanding of the good affects discovery of the real world has divided philosophers for centuries. It has also created unusual alliances. Religiously minded philosophers tend to agree with Plato that truth is discovered only in the light of an idea of the good. In our time, among non-religious philosophers, Heidegger and his followers as well as American pragmatists claim that there is an essential connection between truth and meaning where meaning is exposed only in the light of an idea of the good.

The short text below comes from the portion of The Republic where Plato has his hero, Socrates, give us a picture of the world of appearances and the role of philosophical thinking in coming into the light of truth. The images give us two artist’s renderings of Plato’s famous myth of the cave.

Timothy Hyman, artist

www.crystallinks.com

The Myth of the Cave

Plato Republic VII (514a-521b)

SOCRATES: And now, let me give a parable to show how far our nature is enlightened or unenlightened. Imagine human beings living in an underground cave with an opening upward towards the light, which filters into the depths of the cave. Theses human beings have been here since birth, and their legs and necks have been chained so that they cannot move. They can only see what is directly in front of them, since they are prevented by the chains from turning their heads to either side. At a distance above and behind them is a raised path. And if you look closely, you will see a low wall built along the path, like the screen used by marionette players to conceal themselves from the audience while they show their puppets.

GLAUCON: I see.

SOCRATES: And do you see men passing behind the wall carrying all sorts of objects, such as figures of animals and humans made of wood, stone, and various materials, which they are holding above the wall? Some of the men carrying these objects are talking, while others are silent.

GLAUCON: You have shown me a strange image, and these are strange prisoners.

SOCRATES: They are similar to us. For, initially, how could they see anything but their own shadows, or the shadows of each other, which the fire projects on the wall of the cave in front of them?

GLAUCON: That is true. How could they see anything but the shadows if they were never allowed to turn their heads?

SOCRATES: And wouldn't they see only the shadows of the objects that are being carried by the men?

GLAUCON: Obviously.

SOCRATES: And if these prisoners were able to talk to each other, would they not suppose that the words they used referred only to the shadows that they saw on the wall in front of them?

GLAUCON: Of course.

SOCRATES: And if one of these prisoners was able at last to free himself, and explore to the upper world, would he understand what he saw?

GLAUCON: Not immediately.

SOCRATES: He would have to grow accustomed to the sights of the upper world. First he would be able to see the shadows best, next the reflections of men and other things in the water, and then the things themselves. Afterwards he would be able to gaze upon the light of the moon, the stars, and the spangled heaven. Would it not be easier at first for him to look upon the sky and the stars by night than upon the sun or the light of the sun by day?

GLAUCON: Certainly.

SOCRATES: Last of all he would be able to see the sun, not merely as it is reflected in the water, but in its true nature and in its own proper place.

GLAUCON: Absolutely.

SOCRATES: He will then begin to conclude that it is the sun which causes the seasons and the years, which is the guardian of everything in the visible world, and which, in a certain way, is the cause of all the things that he and his fellows have formerly seen.

GLAUCON: It is evident that he would first see the sun and them reason about it.

SOCRATES: And when he remembered his old habituation, and the wisdom of the cave and of his fellow-prisoners, do you not suppose that he would be happy about his change and pity those who were still prisoners?

GLAUCON: Certainly he would.

SOCRATES: And if they were in the habit of honoring those who could most quickly observe the passing shadows and decide which of them went before others, which came after, which occurred simultaneously--being therefore best able to draw conclusions about the future--do you think that he would care for such honors or envy the possessors of them? Would he not say with Homer, "Better to be the poor servant of a poor master," and to endure anything, rather than think as they do and live after their manner?

GLAUCON: Yes, I think that he would rather suffer anything than accept these false notions and live in this miserable manner.

SOCRATES: Indeed, imagine what it would be like for him to come suddenly out of the sun and to return to his old place in the cave. Would he not be certain to have his eyes full of darkness?

GLAUCON: Most assuredly.

SOCRATES: And while his eyes were filled with darkness and his sight still weak (and the time needed to become re-accustomed to the cave might be very considerable), if there were a contest in which he had to compete in measuring the shadows with the prisoners who had never been out of the cave, would he not be ridiculous? Men would say of him that his ascent and descent had destroyed his eyesight, and thus that it was better not even to think of ascending. And if they caught anyone trying to free another and lead him up to the light, they would put the offender to death.

GLAUCON: Without question.

SOCRATES: You may append this entire allegory, dear Glaucon, to what I have said before. The prisonhouse or cave is the world of sight; the light of the fire within the cave is the sun. And you will not misapprehend me if you interpret the journey upwards to be the ascent of the soul into the intelligible world, which, at your request, I have described. Only God knows whether or not my description is accurate. But whether true or false, my opinion is that in the world of knowledge the Form of the Good appears last of all, and is seen only with an effort. When seen, however, it can only lead us to the conclusion that it is the universal author of all things beautiful and right, that it is the origin of the source of light in the visible world, and the immediate source of reason and truth in the intelligible world. Without having seen the Form of Good and having fixed his eye upon it, one will not be able to act wisely either in public affairs or in private life.

GLAUCON: I agree, as far as I am able to understand you.