In the Second Meditation, Descartes brings his systematic doubt to an end and begins the slow process of piecing together a more secure body of knowledge. The general direction of this Meditation is evident in its subtitle: The nature of the human mind, and how it is better known than the body.
The crucial move in this change of direction is Descartes’ unshakeable certainty about his own existence, the first notion which he finds himself unable to doubt. The cogito provides the first principle he was seeking – and, moreover, it is discovered through reason alone. The very basis of Descartes’ new and indubitable scientific knowledge does not come from sense perception but inward reflection. It is the human mind, and not material bodies, that provides Descartes with his foundation: we know the world from the inside out. The focus of this Meditation is therefore on the nature of the human mind and how it differs from material things.
After establishing the certainty of the claim ‘I am, I exist’, Descartes is concerned to clarify the nature of this ‘I’ – and he does so by applying the method of doubt to his previous conception of self.
But what shall I now say that I am, when I am supposing that there is some supremely powerful and, if it is permissible to say so, malicious deceiver, who is deliberately trying to trick me in every way he can? Can I now assert that I possess even the most insignificant of all the attributes which I have just said belong to the nature of a body? M2 p18
After rejecting all that is open to doubt – his physical form, nutrition, motion, sensation – he concludes that the only essential, indubitable aspect of his self is thought:
I am, then, in the strict sense only a thing that thinks; that is, I am a mind, or intelligence, or intellect, or reason—words whose meaning I have been ignorant of until now. But for all that I am a thing which is real and which truly exists. But what kind of a thing? As I have just said—a thinking thing. M2 p18
The Latin phrase Descartes uses here is res cogitans, a thing that thinks. As the Meditations proceed, he carefully and elaborately separates the mind from the body, carving out a clear distinction between res cogitans and res extensa. This distinction is the foundation of Cartesian dualism, and in the current passage he makes a first, implicit argument for dualism: this is known as the Argument from Doubt.
At this early stage, Descartes sketches only the broad outlines of the nature of mind (or soul – the two terms are synonymous for Descartes). The contents of the mind – any contents of the mind – are referred to as ‘thoughts’: thinking, as will become apparent, is a very broad notion indeed. Elsewhere, Descartes gives a more expansive definition:
By the term ‘thought’, I understand everything which we are aware of as happening within us, in so far as we have awareness of it. Principles I.9
This notion of awareness, or consciousness, characterises Descartes’ psychology. As the definition above suggests, all thoughts for Descartes are conscious thoughts: for something to be a thought, I must be aware of it. This claim was challenged at the time by Antoine Arnauld who suggested an infant in its mother’s womb as a counter-example (OR4 p74). But Descartes did not give ground on this claim: ‘there can be nothing in the mind,’ he insisted, ‘of which it is not aware’ (ibid). This doctrine sounds strange to modern ears, as we have grown comfortable with the notion of an ‘unconscious mind’. However, it is crucial to Descartes’ project as it is precisely the immediate awareness of mental states that gives them the certainty needed to refute the sceptic. At this stage, therefore, we can understand consciousness as merely a limiting condition: by ‘thoughts’, Descartes means any mental state of which the thinker is aware.
These mental states are further described as belonging to the four faculties of intellect (or understanding), will, imagination and sensation. As Descartes will clarify later, the intellect and the will are purely mental; imagination and sensation are ‘hybrid’ faculties affected by the physical world. But at this point, the four faculties serve to categorise all the modes of thinking that Descartes discovers through introspection. For example, he further defines res cogitans as:
A thing that doubts, understands, affirms, denies, is willing, is unwilling, and also imagines and has sensory perceptions. M2 p19
Descartes goes on to make a crucial distinction regarding sensory perceptions. His sceptical method prevents him from trusting in the existence of material objects and their properties. He could, of course, be dreaming the objects he perceives. But there is nevertheless a mental image or representation, a thought, which exists in his mind. The fact of this perception is entirely separate from the question of whether its object exists: it can be true that I have a perception of a table, even if there is no table to perceive. The mental representation, the seeming, is true in the sense of existing in the mind; its relation to the real world, if there is one, has yet to be established.
For example, I am now seeing light, hearing a noise, feeling heat. But I am asleep, so all this is false. Yet I certainly seem to see, to hear, and to be warmed. This cannot be false; what is called ‘having a sensory perception’ is strictly just this, and in this restricted sense of the term, it is simply thinking. M2 p19
Although identifying himself as res cogitans is only the first step in Descartes’ psychology, it is worth asking how satisfactory this type of description is. From a certain perspective, it is not helpful to be informed that the mind is ‘a thinking thing’ – as Pierre Gassendi commented in his Objections, this does not tell us the sort of thing we might want to know:
If we are asking about wine, and looking for the kind of knowledge which is superior to common knowledge, it will hardly be enough for you to say ‘wine is a liquid thing, which is compressed from grapes, white or red, sweet, intoxicating’ and so on. You will have to attempt to investigate and somehow explain its internal substance... Similarly, given that you are looking for knowledge of yourself which is superior to common knowledge (that is, the kind of knowledge we have had up till now), you must see that it is certainly not enough for you to announce that you are a thing that thinks and doubts and understands, etc. You should carefully scrutinise yourself and conduct, as it were, a kind of chemical investigation of yourself, if you are to succeed in uncovering and explaining to us your internal substance. OR5 p71
Gassendi’s atomism shows through here: he expects all explanations to be modelled on scientific explanations (‘chemical investigation’). Descartes, of course, rejects this and insists that the mind is known differently from the body, and in a superior fashion (rational knowledge trumps empirical knowledge). Descartes’ reply to Gassendi’s objection (p71f) is perhaps not very convincing, but it serves to emphasise the phenomenological claim that how things appear to us gives us knowledge of the mind:
... no matter how many attributes we recognize in any given thing, we can always list a corresponding number of attributes in the mind which it has in virtue of knowing the attributes of the thing; and hence the nature of the mind is the one we know best of all. OR5 p72
This suspicion – that empirical knowledge is the most reliable kind – is difficult to shake, and Descartes admits as much:
But it still appears—and I cannot stop thinking this—that the corporeal things of which images are formed in my thought, and which the senses investigate, are known with much more distinctness than this puzzling ‘I’ which cannot be pictured in the imagination. M2 p20
He therefore turns his attention to his idea of material bodies – specifically, a piece of wax – to investigate exactly what he knows. It is worth emphasising that this is a purely phenomenological exercise: Descartes continues to suspend judgement on the real existence of the material world (or the wax), since it could still be a deception of the malicious demon. But there is an idea of the wax in his mind, and unpacking that idea through introspection is how he intends to investigate the nature of matter. Whether or not there exists something to which this idea corresponds, is a question not answered until Meditation Six.
The investigation of the piece of wax depends upon a conception of substance and essence that is assumed throughout the Meditations. What Descartes perceives in the wax are merely attributes or modes: these are properties that belong to the wax, but are not the wax itself. This is evident from the fact that these properties (taste, scent, colour, texture etc) change when the wax melts – and yet the wax itself remains. The essence of the wax must be something else: and for the introspective Descartes, this essence must be defined in psychological terms. The essence of the wax, therefore, is whatever he cannot conceive the wax as not having:
Let us concentrate, take away everything which does not belong to the wax, and see what is left: merely something extended, flexible and changeable. M2 p20
How exactly does Descartes come to this conclusion? He uses the different faculties of his mind to consider the wax, starting with the senses. The features of the wax which he discerned by means of the senses, however, have all changed and can therefore not be essential. The true nature of the wax must be understood in some other way. Descartes next considers the imagination, but this is not up to the task: he simply cannot imagine every possible configuration of the changing wax, but he nevertheless recognises that it is infinitely flexible and changeable. The only other option, therefore, is the intellect: the true nature of the wax is ‘perceived by the mind alone... a case of purely mental scrutiny... grasped solely by the faculty of judgement which is in my mind’ (p21).
In other words, we do not ‘see’ the wax in the ordinary sense of that term; we infer its true nature beneath the perceptible properties. In the same way, when we look out of the window onto the street, we only see hats, coats and shoes; but we infer or judge that there are humans inside them. So Descartes is able to:
... distinguish the wax from its outward forms—take the clothes off, as it were, and consider it naked. M2 p22
And through this act of judgement he transforms his ‘imperfect and confused’ perception into a ‘clear and distinct’ one. The true nature of the (idea of the) piece of wax is a small set of quantitative, mechanical properties, most importantly extension. The material world is, essentially, res extensa.
The passage dealing with the piece of wax is a vivid and memorable account of a familiar philosophical intuition: that appearances are generally unreliable and subject to change, while reality is fixed and stable. By ‘reality’, we usually understand the scientific account of reality:
A pervasive assumption of modern physics is that in order to achieve scientific understanding we must go beyond temporary fluctuations and local variations to an investigation of the permanent structural properties of things. Cottingham p81
There is therefore an assumed distinction between the world as it is described by science, and the common-sense account of things. This is the point that Descartes is making, and it maps onto his clear distinction between the pure intellect (res cogitans) and the embodied mind. As embodied minds we receive the common-sense account through our senses: the world is coloured and textured, it has scent and sound and taste. But the pure intellect understands that objects are merely modes of extension in space.
A more familiar version of the idea is the famous distinction made most explicitly by John Locke between primary and secondary qualities. Primary qualities – size, shape, motion, position, number – are considered to exist independently of any observer: they belong, as it were, to the object. Secondary qualities – colour, taste, smell, warmth, pain – depend upon an observer: they may be caused by the object but they exist only in the observer.
So for Descartes the true nature of material things is extension, and secondary qualities give only an imperfect and confused picture of reality. We understand the world best through our intellectual apprehension of the measurable properties of things. Unsurprisingly, this is a stark rejection of traditional empiricism: it explicitly contradicts the empiricist mantra that everything in the mind comes through the senses. On the contrary, for Descartes the intellect grasps ideas precisely by distrusting the senses. And while this may be an article of faith for rationalists, Descartes is surely overstating the case. The senses play a crucial role in any scientific investigation, and Descartes happily admits this in his scientific works. Still, rhetoric aside, Descartes’ point is a good one: a properly scientific account will go beyond describing how things appear to us and attempt to uncover the hidden causes of things. In this case, that means the true substance of the wax.
There is, however, a problem with the very notion of substance. While we may intellectually construct the concept of a substance to which properties adhere, we have no real understanding of what that substance is like. Gassendi (again) identified the problem in his Objections:
But does this really imply that the substance or nature of the wax is itself distinctly conceived? Besides the colour, the shape, the fact that it can melt, etc. we conceive that there is something which is the subject of the accidents and changes we observe; but what this subject is, or what its nature is, we do not know. This always eludes us and it is a conjecture of sorts that leads us to think that there must be something underneath the accidents. OR5 p76
There is a long history of philosophers struggling to account for the very category of ‘substance’, and the fact is that we do not experience the world in that way. Our immediate response to the world is through our senses, and with a little care we can use that information to provide a functional description of things. To reason beyond that description to an unperceived substance does not appear to add anything to our knowledge – and certainly does not make that knowledge more ‘clear and distinct’.
In the First Meditation Descartes sought to lead the mind away from the senses: by doing exactly that with the piece of wax, he has achieved a very different understanding of his ideas. He will return to this scientific account of the material world in Meditation Six. At this point he has at least shown that there are significant issues with our ordinary view of things obtained through the senses, and thus made plausible his claim in the subtitle that we can know the mind better than the body:
Surely my awareness of my own self is not merely much truer and more certain than my awareness of the wax, but also much more distinct and evident. M2 p22