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So we've got to the end of Meditation One
in which Descartes raises this radical, what we now refer to as radical scepticism. He suggests, maybe I can't know anything at all, maybe I can't be certain of anything. But then he notices that, even if I did persuade myself of something, I had to have existed if I did that. That is, he writes, I am, I exist, that's necessarily true every time that I utter it or conceive it in my mind. And that is the basis of one of the more famous arguments in the Western philosophical tradition, what we now refer to as the cogito argument, where cogito is Latin for "I'm thinking." So here's an argument: premise one: I am thinking. Even if I'm being deceived by Zeke even if the Zeke is producing much chemical stimulation for my brain, I'm still having thoughts. I'm not mistaken in thinking that I'm having thoughts, so that's the first premise. Second premise: I couldn't be thinking unless there were a self there to do the thinking. And I'm not making any substantial assumptions about what that self would have to be. But there must some kind of self, there's no such thing as just free-floating thought, thought must always belong to a mind of some kind. So premise one, I'm thinking, premise two, I couldn't be thinking unless there were a self doing the thinking. Therefore, conclusion: there is a self doing some thinking, that is to say, I exist. So the full formulation in Latin of the argument is referred to as cogito ergo sum, I'm thinking therefore I exist. This is Descartes' way of saying look, at least one thing I can know, I can be certain of, that I exist. How do I know that I exist? Well, even on the most depressing sceptical scenario, even if I'm in Zeke's vat or being deceived by what Descartes refers to as an evil genius, still there must be a self that is there to be deceived. And therefore I can be certain at least of one thing, namely, that I exist. This is what Descartes refers to as an Archimedean point, where Archimedes was an ancient scientist who said, if you give me one unmovable point and a long enough lever, a long enough stick and one that won't break, I can move the entire Earth. So too, Descartes says, I'm going to start out with this Archimedean point that idea that I exist, I can be certain of that. And then look around and ask, is there anything I can build on the basis of that simple observation so that we can begin to reconstruct our knowledge on a firm foundation? Descartes next asks, what kind of being am I? He answers, a thing that thinks. What is that? He answers, a thing that doubts and understands and affirms and denies and wills, refuses and that also imagines and senses. Descartes takes all these to be as it were activities of his mind. And his point is that, for example, when I'm doubting, there too I can be sure that what's going on is that I'm doubting. When I'm affirming, when I say, that proposition, I think it's true, even if I'm wrong in thinking that it's true, I can be right in my judgement that I'm making that judgement, that affirmation. Likewise, if I make up my mind to do something, suppose I will to raise my hand. Even if I'm not sure if the hand goes up, although I have the experience of it's doing so, I can still, Descartes says, be sure that I am willing, that I'm forming the intention to do something. So, it's I who doubt, who understand, and will, it's the same I who senses or is cognizant of bodily things as if through the senses. But he notices that this sensory experience might or might not correspond to anything outside of his own mind. But he still wants to say, it seems to me as if something is going on, I'm having what appears to be sensory experience. So think about the difference between, for example, I'm holding an apple in my hand and it seems to me as if I'm holding an apple in my hand. At least at this point in the meditations Descartes will say, I can’t be sure that I am holding an apple in my hand, maybe I don't even have any hands! But I can still be sure that it seems to me as if that's what's going on. This is what we now refer to as a 2nd order judgment, judgments about my own experiences. Those 2nd order judgments can be things of which I'm sure, or that I can be sure, even if I can't be sure that those 1st order judgments, such as, I have an apple in my hand, are themselves true. Those 2nd order beliefs are things that I also think are indubitable. So what do we have? We can be sure that we exist, and we can also be sure of the truth of these 2nd order beliefs. Even if you're in Zeke's vat, you have no way of proving at this point that you're not. Still, you're having an experience of, for example, it seems to you as if you're sitting in a chair, watching a lecture on your laptop, and Descartes will say, you can be sure that that is how things seem. Descartes generalizes this point, and also moves it further towards his view about how proper progress in the science is going to have to go when he considers a piece of wax. And he says, think about this piece of wax, it's just been taken from the honeycomb. It still tastes of honey and has a scent of flowers, from which the honey was gathered. It's colour, shape, and size are all plain to see, it's hard, cold, and can be handled easily, if you rap it with your knuckle it makes a sound. In short it does everything that seems to be needed for a body to be known perfectly clearly that it seems to hold the wax in my hand. It would seem that I know it as well that I could possibly want to. But, as I speak these words, I hold the wax near to the fire and look: the taste and smell vanish, the colour changes, the shape is lost, this size increases and the wax becomes liquid and hot. You can hardly even touch it and it no longer makes a sound when you strike it. You just get this goop that sticks to your knuckle or something, but it's still the same wax. So what was it about the wax that I understood so clearly? I certainly had a clear mental grasp of the thing, so to speak. Evidently it was not any one of the features that the senses told me of, for all of them brought to me through taste and smell and touch and hearing, they've now all altered and it's still the same wax that I had before. So Descartes wants to suggest now that there's a sense in which I perceive more with my mind than with my senses. Sensory experience is like caloric intake, I need some of it in order to think. But thinking proper doesn't happen until I peer through these sensory experiences of the sensation of yellow or the sensation of sweet smell and say those aren't properties in the wax itself. The wax could lose those properties and still persist, he argues, and yet I'm able to grasp the wax with my mind. How do I do that he asks? By grasping what we now call primary qualities, qualities that are mathematically definable, such as extension, location, space and time, number, mass, velocity, motion and the like. This stuff of physical description; if there are any objects outside of my mind that exist, then, in so far as I know them, I will know them by virtue of those types of properties, those types of primary qualities. Whereas describing something as being yellow or fragrant, soft, hard, as the case may be is not a description of the thing itself, but rather what we now refer to as a secondary quality. And a capacity for the thing to produce an experience in me, and in a way that does not objectively correspond to how things are, so to speak, in themselves. So then, if there is any wax out there, if there are any objects external to my mind then as far as I know them, it's by means of this mathematically expressible description. I need to be able to give it in rigorous mathematical terms otherwise what I'll take to be knowledge will not be genuine knowledge. It'll be more my imposition of my experiential connection with the world than objective, scientific knowledge. So by the end of Meditation Two, Descartes takes itself to know a few thing, first of all that he exists. Secondly, how things seem to him to be, those expressed in second order thoughts, second order judgements; third, what kind of being he is. That's the passage that we quoted talking about, what am I, a thing that thinks and wills and understands, etc. And finally, what properties external objects would have to have if there are any there to be known. And those properties, those primary qualities, have to do with extension, number, location, direction and velocity of movement, etc. Descartes puts that conditionally if there are any things external to my mind and if I know them they would have to be known by means of those sorts of properties.