To distrust those who have deceived us even once

Reading Descartes’ ‘The Search for Truth by means of the Natural Light’ Part IV.

Eudoxus will establish an order for the men to follow. Very well, evident, we need to know where we are going. But when Descartes says ‘order’, it is not merely a word. This word, ‘order’, his entire philosophy is concerned. For in fact, Descartes’ entire project is precisely this; to give order to philosophy. Nothing more, nothing less. He feels that philosophy has been going about in a disorderly fashion, taking a concept from Plato here, another one from Aquinas, and combining it all together, like a child that doesn’t really know what it is doing. This is what philosophy has become, Descartes believes. And so, for the very first time, we must start doing philosophy in an orderly manner, we must give order to our thoughts. What kind of order? An ‘order of reasons’, which means, an order created by that which is clear and distinct —Descartes’ criterium for something being true and reasonable. What makes something clear and distinct? It being evident in and by itself, indubitable. We will start from that which is absolutely certain, and from there we will start our reasoning, and we will only go there where we can maintain this degree of certainty. Very well, isn’t this what philosophy and science have always done? Following ‘certainty’? That is what they have always tried to do, but they have failed in doing so, Descartes will say. Why? Because what they called certain, what they called following ‘reason’, it wasn’t certain at all, it wasn’t reasonable at all. Why? Because they have always sought for an order of reality, which is quite distinct from following the order of reason. How so? The natural scientist claims he is following reason, and he will start his reasoning from empirical facts about the world. He will say, you exist because your mother and father begot you, and they exist because nature existed, and so on —this is certain. Descartes will say that this might well be true, but the scientist wasn’t truly following reason. For these facts, that your mother and father begot you, you can doubt this. You can doubt the existence of the world even. You see, what Descartes means with certainty, it is something foreign to empirical-scientific certainty, it is something else. We will go into this later. For now, we listen to what Eudoxus has to say: 

“Eudoxus: We must begin with the rational soul, for all our knowledge resides in it; and after considering its nature and effects, we shall proceed to its author. When we have come to know who he is, and how he has created all things that exist in the world, we shall be able to see what is most certain regarding the other creatures, and we shall examine in what way our senses receive their objects and how our thoughts are made true or false. Then I shall lay before your eyes the works of men involving corporeal things. After causing you to wonder at the most powerful machines, the most unusual automatons, the most impressive illusions and the most subtle tricks that human ingenuity can devise, I shall reveal to you the secrets behind them, which are so simple and straightforward that you will no longer have reason to wonder at anything made by the hands of men. I shall then pass to the works of nature, and after showing you the cause of all her changes, the variety of her qualities, and how the souls of plants and of animals differ from ours, I shall present for your consideration the entire edifice of the things that are perceivable by the senses.” (Descartes, The Philosophical Writings, Volume II. 405)

Eudoxus then goes on that he will give an account of celestial phenomena, and he will speak about the immortality of the soul. All of this until now he considers to be for the first part of the discussion. And the second part will deal with each science in particular, and propose a method that will advance each individual science even “further forward than has hitherto been achieved”. Moreover, this method will enable even “someone of average intelligence to discover for himself everything that the most subtle minds can devise.” And after this, he will teach us how to control our will by distinguishing good from bad, and virtue from vice. And the end of all this? To prove that every man of good mind can truly satisfy his hunger for knowledge, to prove that any man of good mind can be confident in what he knows. 

Sadly, as I mentioned before, only a small part of the manuscript of The Search for Truth remains to us, and most of these topics are not touched on in what we do possess. 

Eudoxus now says: 

“To enter upon this discussion, we must ask the following question: What are the first things that people know? What part of the soul does this knowledge reside in? And why is it so imperfect to begin with?” 

Of course, Epistemon is the first to give an answer, even though Eudoxus explicitly stated that he wanted him to be quiet in the beginning…

“Epistemon: It seems to me that all this can be explained very clearly if we compare the imagination of a child to a tabula rasa on which our ideas are to be traced, these ideas being like portraits drawn from nature.” 

On this ‘tabula rasa’, Epistemon says, all sorts of artists work, the senses, inclinations, our teachers, and our intellect. Among them, it so happens that the least competent among them are the first to start painting, namely the senses and inclinations. Hence why our knowledge is so imperfect to begin with. Later, our teachers leave a mark on us, and only after they have taught us, our intellect will be trained enough to start working in us, filling our mind with true ideas. Again, for Epistemon, it all starts with what we are learned by others, and only after this can we truly think for ourselves, by way of our own natural intellect. So, for Epistemon, it starts with the senses, and from there we slowly rise to the knowledge by way of intellect, this intellect then slowly corrects the faulty knowledge acquired by the senses. As he says: “the intellect is like an excellent painter who is called upon to put the finishing touches to a bad picture sketched out by a young apprentice.” 

Eudoxus responds that Epistemon’s comparison “nicely illustrates the first obstacle facing us.” But he doesn’t “describe the means we must use if we wish to avoid it.” The ‘first obstacle’ here refers to the faulty knowledge acquired by the senses. And why doesn’t Epistemon show a means to avoid it? Didn’t he say that the intellect must correct the faults of the senses? He did, but this is not enough for Eudoxus… We read:

“Eudoxus: It seems to me that your painter would do far better to make a fresh start on the picture; rather than wasting time in correcting all the lines he finds on the canvas, he should wipe them off it with a sponge.” 

Here it is, the entire radicalism of Descartes. We should not merely try to ‘correct our faults’, mould them into something more refined. NO! If something is false, do away with it, entirely. And start over, entirely. He will say; I do not want to be like those men who merely seek to renovate a house, no, I want to destroy the entire house, and start over from better foundations. Why? Well, why would something have faults? Because it wasn’t built on secure foundations to begin with. Why is knowledge false? Because it wasn’t derived from true knowledge. So what sense is there in saving it? How could something false come out of something that is true? It can’t, Descartes thinks. And how could something true come forth by tinkering with that which is false?

So if we have false knowledge, this means the foundations on which it was based were false. Do away with all of it, and start over from secure foundations. And Descartes will apply this very radically to the knowledge gained by the senses. If this knowledge gained by the senses is very insecure, as everyone agrees on, then why rely on it at all? Why listen to it in the first place, if we know it can potentially lead to erroneous beliefs? Why try to ‘correct’ it, when you can just do away with it? 

“Eudoxus: As soon as a man reaches what we call the age of discretion he should resolve once and for all to remove from his imagination all traces of the imperfect ideas which have been engraved there up till that time. Then he should begin in earnest to form new ideas, applying all the strength of his intellect so effectively that if he does not bring these ideas to perfection, at least he will not be able to blame the weakness of the senses or the irregularities of nature.” 

The very last sentence here fascinates me. If a man follows only his intellect, and he makes a mistake, at least he will not be able to blame the weakness of the senses or the irregularities of nature. A man whose knowledge is based solely on his own intellect, knows what he knows. But he who relies on the senses for knowledge, he doesn’t really know what he knows, he trusts that the senses are giving him an accurate picture, but they could be deceiving him. The certainty of his knowledge doesn’t rely on him, but on nature. And when he makes a mistake, he can always say: ‘ah! It’s not my fault, I was merely deceived by the senses!’. What sort of man is this, is he not ready to take responsibility for what he knows? That he wants to rely on something else but himself to tell him the truth? Are these sorts of questions the questions that Descartes asked himself? 

We go on. 

Epistemon replies that this is an excellent idea, to start over entirely in the certainty of reason, but it is too hard to apply says Epistemon. Why? Because the opinions received by the senses “remain so deeply imprinted that our will cannot erase them on its own.” We cannot just ‘decide’ to stop believing in falsities, they are so deeply imprinted, that we believe them automatically. It is possible, we can effectively adjust our beliefs “by calling on the assistance of powerful reasons”, but it is very hard. And now, Eudoxus will try to give these most powerful of reasons, and he will try to show that it isn’t hard at all to gain sure knowledge. 

“Eudoxus: I should like to try and impart some of these reasons to you. But if you wish to derive any profit from this conversation, you must now give me your attention, and let me converse a bit with Polyander; this will enable me to begin by overturning all the knowledge acquired up to the present. For, since this knowledge is not enough to satisfy him, it must be faulty.” 

Very important, we started the dialogue with Polyander expressing that he wasn’t satisfied with what he knows, and this is why he wants to converse with the other men to begin with. And now Eudoxus says that because he is not satisfied with his knowledge, this means that the knowledge that he has is faulty. Interesting. Eudoxus is saying that if we have true knowledge, we will be satisfied with it, and we won’t really desire to know anything else. To be satisfied with what we know, this is the measure determining whether or not what we know is true.

This faulty knowledge that Polyander has is now compared to a badly constructed house, “whose foundations are not firm.” Eudoxus says that he knows “of no better way to repair it than to knock it all down, and build a new one in its place. For I do not wish to be one of those jobbing builders who devote themselves to refurbishing old buildings because they consider themselves incapable of undertaking the construction of new ones.” 

This beautiful analogy perfectly expresses how Descartes looks at most philosophers; they read books of old, make minor corrections and so on, they refurbish old things to make them better suited for the present. But why do they do this? Maybe because they are not good enough, and not confident enough, to make something entirely by themselves….

“But Polyander, while engaged upon this work of demolition we can use the same method to dig the foundations which ought to serve our purpose, and to prepare the best and most solid materials which will be needed for building up these foundations.” 

Descartes’ ‘demolition’ of the faulty houses is not entirely negative. No, it only seems like this. If we destroy the old and faulty houses of knowledge, what will we find? We will stumble upon the foundations, solid rock, that which remains underneath all the nonsense people think at certain times. We will stumble upon what is unchanging, truly certain, and most ancient of all. And from here, we can build a new house, but this time not straying from the truth of the foundations. 

“So please join me in considering which, of all the truths men can know, are the most certain and the easiest to become acquainted with.” 

Polyander replies: 

“Is there anyone who can doubt that things are perceivable by the senses - by which I mean those which can be seen and touched - are much more certain than all the others? I for one would be quite astonished if you were to make me see just as clearly any of the things which are said about God or the soul.” 

He was clearly not listening when Eudoxus and Epistemon spoke earlier… 

We already know that the things shown by the senses can be doubted, and are not certain at all. What about when we hallucinate, or dream? And what about when we think we see someone we know on the streets, but upon closer investigation, it is just another stranger? But it is still fruitful to investigate Polyander’s claims. Why does he claim that the things perceivable by the senses are much more certain than all the others? Because we see them much more clearly than anything else. You cannot deny this. And Polyander says that these senses allow us to see things much more clearly than any of the things which are said about God or the soul. Indeed, who has ever seen a soul? You cannot see it, and you cannot touch it. Strictly speaking, it cannot even be located in space. And the same things could be said about God. Polyander here takes as his criterium for certainty that something can be seen, that it is visible. And everything that cannot be seen, this is much less certain, because it cannot be seen. We will see soon how Eudoxus/Descartes will critique this point of view. But it is worth noting that this way of thinking of Polyander is very close to our own contemporary way of thinking, or at least, that of the dominant way of thinking about truth —scientism. Scientism too claims that what is seen is what is true, what can be empirically verified, measured, etc., this is what is true. But the soul? This cannot be seen, and thus it does not exist. However, the brain can be measured, and thus this is all there is…

You see, by having Polyander say these words this soon in the dialogue, Descartes tries to paint it as the childish position, the way of thinking of one who has yet to start thinking. But this childish way of thinking, is it any different from how we usually think? A worthy question. 

Now, Eudoxus responds that in actual fact he wants to show the truths about God and the soul are much more certain than the truths gathered by the senses: “I find it strange that men are so credulous as to base their knowledge on the certitude of the senses, when everyone knows that they are sometimes deceptive, and that we have good reason always to distrust those who have deceived us even once.” 

Common folk wisdom; if someone deceives you once, you would be a fool to trust them a second time. Yet, this is what we do all the time when it comes to the senses. They have fooled us many many times, yet we keep trusting them. We keep thinking they will give us the truth. The same could be said about how we trust many other things. It seems almost like a transcendental mistake hardwired in us, to be repeated over and over. The media lies to us once, and yet, many keep trusting them. They can be fully aware they were deceived in the past, yet, they will keep putting their trust in the same media, again and again. It is this general stupidity afflicting humankind, this willingness to be deceived over and over again. And interestingly, Descartes here makes it into an actual philosophical theme, applicable to his theory of knowledge. When it comes to other people, we would be fools to trust them again when they have deceived us once. So why don’t we apply this heuristic to everything else, like the senses? This is Descartes’ question, voiced here by Eudoxus. 

And now, Polyander will show himself to be like one of those idiots who willingly trusts something when it has deceived him in the past: 

“I am well aware that the senses are sometimes deceptive if they are in poor condition, as when all food seems bitter to a sick person; or if their objects are too far away, as when we look at the stars, which never appear so large to us as they really are; or, in general, whenever they do not act freely in accordance with their natural constitution. But such defects of the senses are all quite easy to recognize, and do not prevent me from being quite sure at present that I am seeing you, that we are walking in this garden, that the sun is shining on us, and in a word, that everything which ordinarily appears to my senses is genuine.” 

Polyander has a great point, but Eudoxus/Descartes will not accept it. You see, the latter is a radical. Someone has deceived you once, never trust them again, by principle. And for Eudoxus, it seems only that Polyander is now trying to make excuses. ‘yes yes this person lied to me, but really he is still a good guy to be trusted most of the time.’ ‘The senses have deceived me yes, but look, they are really not all that bad to me.’ 

Eudoxus replies with the famous dream-argument. Have you not had dreams, he asks, in which you experienced things just like you do now when you are awake. “How can you be certain that your life is not a continuous dream, and that everything you think you learn through your senses is not false now, just as much as when you are asleep?” 

What can you say, Descartes really is this radical. We are doing philosophy here, which means we are searching for the truth. And more, we are searching for that truth of which we can be absolutely certain. Yet, you claim to find the truth by way of the senses, when they deceive you constantly. How is this going to offer us that truth which we seek? Indubitable, self-same at all times, clear and distinct. 

Descartes says; we have been doing philosophy in a very unserious manner. In life, interacting with others, making a livelihood, etc., we are much more serious. Here, when someone deceives us, we will never trust them again. For sometimes, our lives depend on it. But, when we are doing philosophy, when we are asking for that which is really certain. When we are doing this, it seems we lack this seriousness that we naturally have in daily life. And Descartes, he wants to bring it into philosophy. You manage your life by way of principles, you seek to live in an orderly manner by acting on principles, your life depends on it. Why not do the same in philosophy? Why not, for once, take philosophy seriously?

Sources: 

Descartes. Œuvres philosophiques II 1638-1642. Edition de F. Alquié. Paris: Garnier, 1967.

Descartes. The Philosophical Writings: Volume I. Translated by John Cottingham, Robert Stoothoff, Dugald Murdoch. Cambridge: Cambridge University Press, 1984.

Descartes. The Philosophical Writings: Volume II. Translated by John Cottingham, Robert Stoothoff, Dugald Murdoch. Cambridge: Cambridge University Press, 1984.