2 00:00:06,936 --> 00:00:10,900 Welcome back to Know Thyself: On
the Value and Limits of Self-Knowledge. Today our second class will be entitled Descartes' Essence and as you can guess, it will be about the philosopher named Descartes. Rene Descartes was a philosopher whose dates were 1596 to 1650. And he was a French philosopher, scientist, as well as a mathematician. He was the inventor of Analytic Geometry. He is the person who after whom the Cartesian coordinate system is named. If you've done any graphing you've probably used Cartesian coordinate systems. And he had interests in optics and meteorology as well. And he's commonly credited with inventing what we now refer to as the Modern era of philosophy. In philosophy, things move pretty slowly, so that in other fields what's referred to as modern, might refer to the last ten or fifteen years. Whereas in philosophy what we refer to as modern tends to be about the last four centuries! And Descartes was, it seems, wary of the fate of Galileo down in Italy, who had been subject to the Inquisition for having challenged some authoritative teachings of the Church. Descartes might have been trying to be careful not to get in similar kinds of trouble in the course of trying to pursue his own ideas. And if you want to read some of the writings that Descartes produced that will help you understand some of the things we're talking about here in this course and deepen your knowledge, you will find online a website called Early Modern Texts (earlymoderntexts.com). I'll also be posting a URL for you on the course website. And Jonathan Bennet, the distinguished philosopher, has translated Descartes, as well as many other philosophers, into contemporary idiomatic English. And in the case, in particular, of Descartes, he has embellished the text a little bit in order to make it a bit more accessible to readers who are new to the material. So what is he about? What is his enterprise? What is he trying to accomplish? Well Descartes had a number of aims in this essay called The Meditations. He wanted to use reason as opposed to, for example, divine revelation in order to establish Theism. Theism is the belief in the existence of God, usually defined in the western Judeo-Christian tradition as the being than which there can be no greater. And that's usually in turn defined as a being that has all possible perfections such as omniscience, omnipotence, omnibenevolence, etc. So any perfection that God has, that God might be thought to have, God in fact has by that definition. Descartes wanted to argue for Theism in that sense that a God so defined does in fact exist. Descartes just as importantly wanted to establish a new foundation for the sciences. The science of his day that he was raised in and his early education was heavily influenced by scholastic philosophy. This was in turn heavily influenced by Aristotelian science. And although there is a great deal to be said for Aristotelian science, it tended to, so to speak, posit a level of mindedness, of animacy, in what we now think of as inanimate objects. So, to put the thought very simply, in Aristotelian and thereby scholastic science, it was not uncommon to explain why, for example, a rock fell towards the surface of the earth when thrown up into the air. On the basis of the hypothesis that the rock had a kind of, the term was conatus, something like an implicit unexpressed desire to end up at what it took to be the centre of the universe. Descartes though that that was positing a level of mindedness in what he thought was an otherwise mindless nature. And he wanted to come up with more rigorous, scientific explanation of natural phenomena and, as we just saw a moment ago, the developer himself of a powerful new set of mathematical tools. He wanted to, as we now describe it, mathematize nature as much as possible. To explain how it is that things happen in the world outside of our minds in a way that can be clearly and rigorously expressed in mathematical terms and also explained by means of mathematically expressible laws. Descartes also wanted to prove that the mind's a distinct kind of substance from the body. He took it that the mind is not something that can be fully explained in purely physical terms and he gives an argument for that that we'll see in just a moment. Part of Descartes' method will be to demand that as much as possible our mind, in the course of inquiry into ourselves and the world around us, be free from prejudices and withdraw as much as possible from association with the senses. And in the course of arguing for this position, Descartes' going to be championing what he thinks of, or we now think of as an alternative to Empiricism, namely, Rationalism. Whereas Empiricism is the view that all knowledge comes from, and only from the senses, Rationalism is a view that opposes that. And while it's not always clearly and precisely defined, roughly speaking, Rationalism is going to be for our purposes the doctrine. That proper use of our reasoning faculties will give us the information that we need about our nature about what is right and what is wrong, about mathematics, about the world around us, and perhaps even, and hopefully as well, even about God. And as I mentioned, Rationalism's ancient rival is Empiricism. When you first hear Empiricism, you will probably find that it seems obvious, that it seems it's hard to deny that all knowledge come from and only from experience. But if you reflect more on Empiricism you might begin to have some questions. For example, we take it that there are two kinds of knowledge roughly speaking, one kind of knowledge is a posteriori. That knowledge that's got from experience, but there seems to be other kinds of knowledge. That we might think of as, a priori, prior to experience. So think about your belief, which in some cases you might also consider to be a case of knowledge that, for example, certain mathematical claims are true, that two plus two is four, that the interior angles of a triangle add up to 180 degrees. Those are things that I doubt you'll be able to verify to establish by empirical means. It's not clear what tests you could undertake to determine conclusively that two plus two is four. That the interior angles of a triangle add up to 180 degrees. Claims of mathematic seem very secure, very certain, but they don't look like the things that we can know by means of empirical investigation. The empiricist owes us an answer to how do we know such things. That's one kind of case. Another kind of case that seems to be at least prima facie challenge to empiricism is the confidence that we seem to have, many of us take ourselves to know that there are certain things that are right, other things that are wrong. Think about various forms of behaviour that you feel sure are absolutely immoral. And other forms of behaviour that you feel sure are absolutely moral. For example, for the former case, taking pleasure in torturing a small child, for example. Most of us will feel not just that it's a matter of opinion that such a thing is wrong, but that we feel sure that that's just a fact. Now, as far as we think that, we take ourselves to know probably that such a behaviour is wrong. But what empirical investigation could establish that? What empirical inquiry could determine that such a thing is immoral? After all, there are plenty of cases in which we cause young children pain, for example, when we give them shots to vaccinate them that we don't take to be wrong and don't take to be immoral. So, just the sheer fact that we're causing someone pain doesn't make it wrong. What is it about, for example, torturing a child for your entertainment that makes it wrong. And if we can explain that, it's not clear how we can explain it in empirical terms. The rationalist wants to come back with an explanation of those kinds of knowledge. And then will in turn try to generalize the method to account for, in a sense, how it is that we need to use our rational faculties to get even knowledge of the external world, that a posteriori knowledge that I mentioned a moment ago. Among other famous philosophers who were rationalists besides Descartes were Spinoza, Leibniz, and Malebranche. Rationalists emphasized the use of reason, but few would deny that we get anything at all from the senses. The issue is rather what the senses provide. Do the senses provide information of a sort that can be turned straight away into knowledge? Or does what the senses provide, more like the way in which food provides calories, which indirectly enables us to think. And indirectly enables us to produce knowledge, but there's no direct link between caloric intake and knowledge. And so, to the rationalists, might want to say there's no direct route between sensory and experience and knowledge as well. You can find roots of rationalism in Socrates himself who we discussed in our last lecture. So, for example, in the dialog known as the Meno, Socrates uses what we refer to recently as Socratic Method. Asking someone questions without telling them anything, but in the process, getting them to come to a realization on their own. In the Meno, Socrates has a discussion with his friend, Menos, one of his slaves, a boy. And he gets the boy to see without, Socrates claims, any suggestions or any statements or any implicit leading of the questions that he asks him. He gets the boy to see the truth of a geometrical theorem. And Socrates says, this boy came to see that a certain theorem in geometry is true but I didn't tell him anything. And furthermore, it's not likely that he learned this theorem of geometry on his own in the course of his ten years on this earth as a slave on Meno's estate. So Socrates infers he must have had it in him already, it must have been innate inside of him. Socrates suggests therefore that the, Meno's slave boy, and generalizes it to the rest of us, must have had a soul that pre-existed the embodiment of that soul in our physical body, firstly. And secondly, that soul must have been something in which there is some kind of reservoir of information. If not actually knowledge, then what Socrates will refer to as true opinion. In the Phaedo, another dialogue that is the description of the very last moments of Socrates before he actually drank the hemlock, Socrates tells his friends that death is the separation of the soul from the body, and makes the surprising claim that what the philosopher does for most of his or her life is freeing the soul from association with body as much as possible. He says at one point that the soul reasons best when none of the senses troubles it. Neither hearing nor sight nor pain nor pleasure, but when it is most by itself, taking leave of the body, and as far as possible having no contact or association with it in its search for reality. So Socrates suggests that there's a sense in which thinking is done, can be done, and probably will be done best, when you detach yourself from sensory experience and think on your own. And if it all possible, do so in a way that is completely separated from your physical being. In that respect you will be engaging in thinking at its best, you will be most likely to acquire knowledge, but doing so requires pushing away sensory experience. This point of view, therefore, is Socrates' way of expressing a rationalist position that will be dormant for some centuries, and then come to resurface in the work of Descartes.