In the First Meditation reasons are provided which give us possible grounds for doubt about all things, especially material things, so long as we have no foundations for the sciences other than those which we have had up till now. Although the usefulness of such extensive doubt is not apparent at first sight, its greatest benefit lies in freeing us from all our preconceived opinions, and providing the easiest route by which the mind may be led away from the senses. The eventual result of this doubt is to make it impossible for us to have any further doubts about what we subsequently discover to be true. Synopsis p9
In the Meditations, Descartes sets out to establish the possibility of certain knowledge. Bernard Williams has called this the Project of Pure Enquiry: an attempt to ground and attain knowledge unconstrained by any previous assumptions or for any partisan purpose. Such a fundamental exercise is explicitly a once-in-a-lifetime enterprise:
I realized that it was necessary, once in the course of my life, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last. M1 p12
Throughout his life Descartes was convinced of the unity and certainty of knowledge, by which he meant scientific knowledge (he uses the Latin term ‘scientia’ to denote such systematic, reliable knowledge as opposed to inherited or common-sense beliefs). It is such knowledge that he addresses in the Meditations. He is not seeking particular facts but the foundations for the possibility of knowledge: if the project succeeds, science will be shown to be possible. This is a significant aim: Descartes’ concern is legitimate since, as Williams says (64), ‘knowledge does have a problematical character’ and the threat of scepticism is real. The question that Descartes asks in the Meditations is therefore a good one: if his answer is not satisfactory, then the question remains.
One characteristic feature of Descartes’ project is his deep distrust of the senses. As the Synopsis makes clear, the aim of the Meditations is to lead the mind away from the senses, the main source for our ‘preconceived opinions’. This distrust of observation may seem odd in one of the fathers of modern science, but the fallibility of the senses is a philosophical staple: and the unsatisfactory notion of science which was prevalent at the time, the Aristotelianism ‘which we have had up till now’, often provided little more than exhaustive classifications of observations and a stale reliance upon traditional authorities. For Descartes, on the other hand, the aim was to accurately distinguish true from false perceptions, and to be able to do that requires a principle or rule that is, of course, not dependent upon the senses (if it were, it too could easily be called into question). The criterion of truth that he is seeking can be found (he believes) in certainty.
This is not an obvious move. Descartes is looking for truth, and he identifies truth with his own certainty: a claim is true if it is certain, if he is unable to doubt it. Truth is normally considered a feature of the independent world, and this shift from external truth to internal certainty is characteristic of Descartes (and has serious implications for his arguments). It also helps to explain the peculiar form and tone of the Meditations themselves. The search for truth takes place in the first person: each reader is encouraged to discover the truth for themselves. In the Preface, Descartes insists that he is writing for:
... those who are able and willing to meditate seriously with me, and to withdraw their minds from the senses and from all preconceived opinions. Preface p8
The search for truth is a journey inwards, not outwards. The Meditations offer a guide to that journey, through doubt to certainty and ultimately scientific knowledge.
Throughout the First Meditation, Descartes employs a number of associated images: knowledge is an ‘edifice’ or a ‘building’ established on ‘foundations’ that must be ‘demolished’ and so on. This way of talking derives from a model of knowledge known as foundationalism. The metaphor is straightforward: all beliefs are derived or deduced from more fundamental beliefs, which themselves depend on yet more fundamental beliefs, and so on down to the very ‘foundations’ of knowledge. If the foundations are secure, then all knowledge derived from those first principles can be trusted: if not, the whole ‘edifice’ is in danger of collapsing. Descartes’ scepticism is therefore directed at the very basis of his beliefs:
Once the foundations of a building are undermined, anything built on them collapses of its own accord; so I will go straight for the basic principles on which all my former beliefs rested. M1 p12
He does not specify what these ‘basic principles’ are, and as they play no further role perhaps that is not surprising. But it is generally assumed that one of these principles is ‘trust the evidence of your senses’: and that is a principle that Descartes does not believe is secure. Descartes therefore uses sceptical doubt as a way of testing all the beliefs and principles that he has trusted until now. The scope of this enquiry is wide: he is seeking to establish secure foundations for all human knowledge, particularly scientific knowledge. With these foundations in place, he hopes to provide a framework for the development of science and, more importantly, a guarantee of its truth.
The investigation is typically psychological. Descartes will internally examine his beliefs and identify those that seem certain and those that can be doubted; and then he will withhold belief from those that are not indubitable. Belief, for Descartes, is a matter of the will: to believe is to assent to an idea or a proposition in the intellect.
So in future I must withhold to my assent from these former beliefs just as carefully as I would from obvious falsehoods, if I want to discover any certainty. M1 p15
(It is worth noting that not all philosophers have agreed with this model of belief. Spinoza, the next major rationalist after Descartes, insisted that ‘belief is not a voluntary action, not something that we decide to do, but something that happens to us, that coming to believe is something much more like falling in love than like raising one’s arm’ (Curley p178). Certainly, the degree of choice involved in what we believe is not always obvious. Descartes returns to this question of will and belief in Meditation Four.)
In one of his replies to Father Bourdin, Descartes uses a different metaphor to explain his method:
Suppose he had a basket full of apples, and being worried that some of the apples were rotten, wanted to take out the rotten ones to prevent the rot spreading. Would he not begin by tipping the whole lot out of the basket? And would not the next step be to cast his eye over each apple in turn, and pick up and put back in the basket only those he saw to be sound, leaving the others? OR7 p63
So Descartes intends to empty his mind and allow in only those beliefs that are ‘sound’. Some philosophers have argued that this is incoherent. The process of comparing and evaluating beliefs requires other beliefs to be in place: for example, that one’s beliefs can be doubted, that beliefs may be true or false, and so on. To jettison also these beliefs (which Descartes implies when he describes ‘tipping the whole lot out of the basket’) would render him unable to investigate anything at all.
In fact, the metaphor of the basket of apples is misleading. Descartes acknowledges that, unlike the apples, he could not examine every single one of his ideas: this ‘would be an endless task’ (p12). Instead, he needs a more general approach enabling him to investigate types or classes of belief. He therefore constructs a careful and systematic method of doubt which starts from particular instances and leads up to a wholesale rejection of almost all beliefs. This is not only practical, but also conforms to his wider purpose: Descartes is not concerned about individual facts, but about the standards we use when we accept them.
It is worth emphasising that Descartes is not a sceptical philosopher (unlike, say, Michel de Montaigne or David Hume). As the remaining Meditations will reveal, the scepticism of the First Meditation is purely instrumental: it is a means to a far from sceptical end. (This should not be surprising in a philosopher whose explicit aim is to establish the indubitable truth of science.) For this reason, Descartes develops his scepticism far beyond ordinary, reasonable levels: this is hyperbolic, philosophical doubt. In ordinary affairs we have a working concept of ‘reasonable’ doubt, and are prepared to trust matters that are beyond that level of doubt. Descartes, however, sets the bar much higher. The criterion of certainty in the Meditations is that a belief must be beyond any possible doubt – ‘completely certain and indubitable’, as Descartes puts it (p12). Setting the standard of certainty so high – as high, in fact, as it can possibly be set – gives the opportunity of discovering whether such absolute certainty is in fact possible. There is a lot at stake: this criterion of certainty will determine the first principles, the ‘foundations’ of scientific knowledge. If those foundations are anything but completely certain, then the whole edifice may come crashing down. It is for this reason that Descartes seeks the strongest possible certainty by applying the most stringent scepticism to his beliefs.
Most of the techniques and thought-experiments that Descartes employs in this Meditation are not original. In the previous century, the work of Sextus Empiricus had been rediscovered and published. Sextus was a Greek doctor writing at the end of the second century, and his Outlines of Pyrrhonism is an extensive compilation of sceptical arguments, techniques and tropes from Greek and Roman philosophers. These sceptical ideas had an enormous impact, particularly on Descartes’ fellow countryman, Michel de Montaigne, and several arguments and examples from Sextus reappear in the First Meditation. Nevertheless, Descartes’ dramatic portrayal of his scepticism is undeniably vivid and effective.
The systematic application of doubt has three main stages, each more comprehensive in its scope. First, Descartes doubts the reliability of his senses based on previous errors or illusions. Second, the possibility that he is dreaming undermines his confidence in any perceptual state. Third, the idea of a deceiving God allows him to doubt even simple logical claims.
The first stage of doubt concerns information gained through the senses. Descartes’ stated concern is to lead the mind away from the senses, and eventually replace this unreliable picture of the world with a mathematical description of reality. He deploys the common Argument from Illusion to make his point:
... from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once. M1 p12
This is such a familiar philosophical point that he does not provide here any particular instance of sensory deception, but elsewhere in the Meditations we find useful examples: in Meditation 6 he mentions square towers that look round from a distance, enormous statues which appear smaller when viewed from the ground, and the interesting illusion of pain in an amputated limb (p53); in Meditation 3 he notes that the sun seems very small (p27); and in the Sixth Replies he deals with the textbook example of a stick appearing bent in water (p64f).
The Argument from Illusion claims that ours senses sometimes mislead us: but Descartes insists that we should go further and distrust all sensory information. Pierre Gassendi rejected this step in the argument (OR5 p63f) and insisted that we can, with caution, trust our senses: in fact, we use other senses to correct initial mistakes, for example by touching the tower to make sure it is not round. But this objection misses Descartes’ point. He is seeking a criterion of absolute certainty, beyond any possible doubt; and since the senses are sometimes unreliable, they must fail to meet his extremely high standard. At any given moment, he may be mistaken in what he perceives. This is enough to establish the first doubt.
The second stage involves the Argument from Dreaming. This is an old argument that appears in The Book of Chuang Tzu, a Chinese text from the 4th century BC:
Once upon a time, I, Chuang Tzu, dreamt that I was a butterfly, flitting around and enjoying myself. I had no idea I was Chuang Tzu. Then suddenly I woke up and was Chuang Tzu again. But I could not tell, had I been Chuang Tzu dreaming I was a butterfly, or a butterfly dreaming I was now Chuang Tzu? p20
Descartes uses the argument to cast his doubt more widely, encompassing any perceptual state, however vivid. This is because, he claims, experiences in dreams are as realistic as experiences while awake:
I see plainly that there are never any sure signs by means of which being awake can be distinguished from being asleep. M1 p13
This may well have been Descartes’ own experience [1] but other philosophers have objected to this claim, insisting that there are clear signs allowing us to distinguish between dreaming and waking. Consistency, persistence of objects, the operation of physical or natural laws – all have been offered as characteristics of reality absent in dreams. However vivid a dream appears at the time, we are usually able to recognise it as a dream upon waking. In fact, Descartes will later reject the Argument from Dreaming himself on the grounds that a rational examination of dreaming and waking states reveals such a difference: ‘when I can connect my perceptions... with the whole of the rest of my life without a break, then I am quite certain that... I am not asleep’ (p62). At this stage of his investigations, however, he seems right to note that any isolated experience could be indistinguishable from a dream (and the Deceiving God Argument will shortly remove any confidence he has in such rational examinations). Even if we can recognise a dream after waking, at any given moment we may be mistaken in thinking that we are awake. Moreover, whatever criterion we use to distinguish dreams from waking states may itself be the object of a dream.
The Argument from Dreaming, then, presents a strong sceptical challenge to Descartes’ beliefs. It also has a wide scope, encompassing every possible state of affairs. But Descartes acknowledges the empiricist claim that our ideas must ultimately derive from experience: even if I am dreaming of an imaginary creature with two heads, the basic elements of that picture – body, heads – must come from somewhere. And even if there are no such things as bodies or heads in reality, the ‘simpler and more universal’ aspects of such pictures – extension, shape, quantity, size, number, place, time – must surely be real:
For whether I am awake or asleep, two and three added together are five, and a square has no more than four sides. It seems impossible that such transparent truths should incur any suspicion of being false. M1 p14
The third stage of doubt is designed to cast suspicion upon even such apparently indubitable claims as 2 + 3 = 5: that is, a priori knowledge that is not based upon perception and seems necessarily true. This argument takes the form of a dilemma. If an omnipotent God exists, then surely He (by definition) has the ability to deceive in even the most elementary matters:
... how do I know that God has not brought it about that I too go wrong every time I add two and three or count the sides of a square? M1 p14
On the other hand, if there is no God – if a human being is the product of purposeless chance – then it is more likely that the human mind is imperfect and can be deceived. These two options seem to prevent any belief from being certain: it may seem impossible to be mistaken about the number of sides in a square, but elementary mistakes in addition are common enough and an omnipotent being could presumably mislead in such matters. By this point, Descartes is no longer concerned with objective reality – that can easily be doubted as God’s deception:
How do I know that he has not brought it about that there is no earth, no sky, no extended thing, no shape, no size, no place, while at the same time ensuring that all these things appear to me to exist just as they do now? M1 p14
More significantly, the Deceiving God Argument allows Descartes even to doubt conceptual claims. Otherwise, it would be possible to be certain that triangles have three sides or that identical things are the same size (regardless of whether triangles or things actually exist). With this third step, Descartes seems to have cast doubt on every possible belief.
In a sort of coda to his scepticism, Descartes introduces the malicious demon, mainly as an effective antidote to his slipping back into old and comfortable ways of thinking.
I will suppose therefore that... some malicious demon of the utmost power and cunning has employed all his energies in order to deceive me. M1 p15
The malicious demon allows Descartes to subtly shift his sceptical approach from ‘I may be mistaken at any time’ to ‘I may be mistaken all the time’. The demon is not capable of more than the Deceiving God, but is devoted to the act of deception (hence malicious) which accounts for the permanent possibility of error. It is the malicious demon that is usually intended when referring to ‘Cartesian’ doubt; or, perhaps, the more modern analogue of a disembodied brain in a vat being stimulated to perceive an artificial reality (and, of course, see The Matrix or The Truman Show for Hollywood versions of the same idea). But it should be noted that the demon is merely a shorthand for the more systematic and plausible scepticism generated by the preceding three stages of doubt.
It is not clear that such sweeping universal scepticism is, in fact, coherent. Once Descartes has suggested that a priori truths are open to doubt, it seems that there is nowhere left to go. If he doubts even the basic processes of reasoning, he will be unable to trust any beliefs at all (however clear and distinct they seem to him) including such crucial beliefs as that God will not deceive him. In this sense, hyperbolical doubt appears self-defeating: the act of doubt itself presupposes basic notions, including a distinction between true and false, that he can no longer trust.
The distinction between truth and illusion is instructive. For the two terms to have meaning, each must refer to something different: there must be a truth to contrast with illusion. An analogy with counterfeit coins makes the point: for some coins to be counterfeit, some must be genuine. If all coins are counterfeit, then the term loses any meaning. The scenario of the malicious demon seems all-embracing: every experience is, in this sense, counterfeit – and if everything is an illusion, if illusion is all there is, then the terms ‘truth’ and ‘illusion’ are drained of significance. In the light of this, the malicious demon hypothesis feels empty. (Contrast with The Matrix and The Truman Show, in both of which a distinct reality is accessible outside the illusion). But we should remember that the situation looks different from Descartes’ point of view: it is perfectly possible that all of his experiences are illusory (just as all of his coins may be counterfeit) as long as the possibility of truthful experience exists. And for all he knows, that may well be the case.
But in the end, none of these concerns are important. Philosophers have been troubled by Descartes’ sweeping distrust of the senses or his hypotheses of radical deception, and examples of this can be found in the Objections. But such complaints are ‘curiously irrelevant to what Descartes is trying to do’ (Cottingham p30). We should remember that Descartes is not arming or defending the sceptic: on the contrary, his use of sceptical arguments is solely a means to an end. Cartesian doubt is ‘a mechanism for the production of first principles’ (ibid p34). Rather than accepting traditional beliefs, he is changing the burden of proof: his opinions need to show that they are immune to doubt. Any technique that tests those opinions will do, even if at some level such doubts cannot be sustained.
With dramatic flair, Descartes ends the First Meditation on a cliffhanger. The hypothesis of the malicious demon seems to have rendered every possible experience doubtful: there is not a single belief that meets his strict standard of certainty. The reader is left deeply disoriented. As Descartes describes it in the following Meditation:
I have fallen unexpectedly into a deep whirlpool which tumbles me around so that I can neither stand on the bottom nor swim up to the top. M2 p16
Of course, it is precisely this sort of epistemological confusion that Descartes hopes to dispel by establishing scientific knowledge on a certain foundation, and so refuting the sceptic once and for all.