René Descartes’ Meditations on First Philosophy (1641) begins from a position of radical doubt – questioning everything that can possibly be doubted – in the search for a foundation of certain knowledge.
The first certainty Descartes arrives at after this initial period of doubt is that he himself exists, as captured in the famous cogito argument (“I think, therefore I am”).
From there, Descartes continues to rebuild his understanding of the world, turning next to the question of how we know about physical objects:
“Let us begin by considering the most common things, those which we believe we understand the most distinctly, namely, the bodies we touch and see.”
– Descartes, Meditations on First Philosophy, Meditation 2
This question of physical objects – matter that is extended in space – is where the wax argument comes in.
The wax argument
Descartes begins by considering a piece of wax in his hand:
“Let us take, for example, this piece of wax which has just been taken from the hive; it has not yet lost the sweetness of the honey it contained; it still retains something of the smell of the flowers from which it was gathered; its colour, shape and size, are apparent; it is hard, cold, it is tangible; and if you tap it, it will emit a sound. So, all the things by which a body can be known distinctly are to be found together in this one.
– Descartes, Meditations on First Philosophy, Meditation 2
He points out its sensible properties – the colour, shape, size, smell, and taste – that he perceives via his senses. We might take such perceptions to be how we know about physical objects – we might take such sense experience to be the origin of our idea of physical object.
But Descartes points out that, when placed near the fire, all these properties of the wax can change:
But, as I am speaking, it is placed near a flame: what remained of its taste is dispelled, the smell disappears, its colour changes, it loses its shape, it grows bigger, becomes liquid, warms up, one can hardly touch it, and although one taps it, it will no longer make any sound. Does the same wax remain after this change? One must admit that it does remain, and no one can deny it. What, then, was it that I knew in this piece of wax with such distinctness? Certainly it could be nothing of all the things which I perceived by means of the senses, for everything which fell under taste, smell, sight, touch or hearing, is changed, and yet the same wax remains.”
– Descartes, Meditations on First Philosophy, Meditation 2
Despite all the sensible properties changing, we still take this object to be the same piece of wax. So, Descartes takes this to show that the idea of the piece of wax doesn’t come from the senses.
So, if the idea of the wax doesn’t come from the senses, where does it come from? Descartes next considers that the idea of the wax is produced by his imagination:
“Perhaps it was what I now think, namely, that the wax was not the sweetness of honey, or the pleasant smell of flowers, the whiteness, or the shape, nor the sound, but only a body which a little earlier appeared to me in these forms, and which is now to be perceived in other forms. But to speak precisely, what is it that I imagine when I conceive it in this way? Let us consider it attentively, and setting aside everything that does not belong to the wax, let us see what remains. Indeed nothing remains, except something extended, flexible and malleable. Now, what does that mean: Flexible and malleable? Is it not that I imagine that this wax, being round, is capable of becoming square, and of passing from a square to a triangular figure? No indeed, it is not that, for I conceive of it as capable of undergoing an infinity of similar changes, and as I could not embrace this infinity by my imagination, consequently this conception I have of the wax is not the product of the faculty of imagination.”
– Descartes, Meditations on First Philosophy, Meditation 2
But Descartes rules imagination out too, because the imagination can only picture particular forms or shapes – a round piece of wax, a square one, perhaps even a blob of melted wax – but not the infinite range of possible forms that the wax could take. The concept of the wax could take an infinite number of forms, but Descartes’ imagination is only able to consider a finite number of forms. So, he says, the idea of the wax can’t come from imagination either.
So, the idea of the wax doesn’t come from the senses, nor does the idea of the wax doesn’t come from the imagination. Instead, says Descartes, the idea of the wax comes from the intellect – from the understanding:
“it is now known to me that, properly speaking, we perceive bodies only by the understanding which is in us, and not by the imagination, or the senses, and that we do not perceive them through seeing them of touching them, but only because we conceive them in thought“
– Descartes, Meditations on First Philosophy, Meditation 2
Unlike imagination, the intellect or understanding is not about forming mental pictures at all. When you imagine the wax, you might picture it as a solid yellowish lump, a puddle of liquid wax, or a cube – but the imagination can only ever represent one particular form at a time. It is limited to finite shapes and sizes. But when Descartes understands the wax as something extended, flexible, and changeable, he is not picturing these qualities; he is recognising them through thought alone – through the intellect.
So, the intellect allows him to conceive of the wax as a substance capable of taking on an infinite number of forms – something the imagination could never fully represent. This is why Descartes concludes that the idea of the wax, and our knowledge of physical objects in general, comes not from the senses or imagination, but from the intellect.
Rationalism vs. empiricism
Descartes’ wax example is often used as an argument in support of rationalism and against empiricism.
Empiricism says all knowledge and ideas come from experience whereas rationalism disagrees. Rationalists say some ideas and knowledge are entirely a priori – they don’t require experience.
The wax example supports the rationalist view. Experience, through the senses, tells us only about the wax’s changing appearances – its colour, texture, smell, and shape. But when all these sensory qualities change, we still recognise the same piece of wax. So, real knowledge of what the wax is – its substance or essence as an extended, physical thing – cannot come from the senses. It comes instead from the mind’s ability to think and reason clearly about it.
Summary
- I have an idea of this bit of wax
- I melt this bit of wax and its sensory properties become totally different (e.g. different shape, feel, etc.)
- But I still believe it’s the same bit of wax
- So my idea of what the wax is can’t come from experience of its sensory properties (because those can change and yet I still believe it’s the same piece of wax)
- The wax could appear to me in infinitely many different ways
- But I can only imagine the wax in a finite number of ways
- So my idea of what the wax is can’t come from imagination either (because my imagination can’t account for the infinite ways the wax could exist)
- So where does my idea of the bit of wax come from if not experience or imagination?
- Descartes’ answer is that the idea of the bit of wax is the idea of a particular physical thing (i.e. a thing that is extended in space and can change) and that this concept of physical thing exists in his understanding (rather than coming from imagination or perception)
- This wax argument can be used to support rationalism because it suggests the idea of physical object does not come from experience.