When the term 'modern philosophy' is used in
universities, it's usually to make a distinction from ancient and medieval philosophy. So, it doesn't mean just the philosophy
of our own day here in the 20th century, it means the philosophy
of the last four centuries. In fact, there's one man who is generally,
and I think rightly, regarded as the inaugurator of modern philosophy:
the Frenchman Descartes. So in practice, what the term 'modern philosophy'
means is philosophy from Descartes onwards. Rene Descartes was born in France in 1596. He received an unusually good education,
but he also had unusual independence of mind. And while still young, he perceived that
the various authorities he was studying quite often put forward
arguments that were invalid. As a young man, he became a soldier and traveled
widely in Europe, though without seeing any fighting. And he was struck by the fact that the world
of practical life was as full of contradictions as the world of books. He became fascinated by the question whether
there was any way at all in which we human beings could get to know anything
for certain. And if so, how? He stopped traveling and went into seclusion
in Holland, the country in which intellectual life in those days was at its freest. There, during the 20 years from 1629 to 1649,
he produced work of the profoundest originality in mathematics and philosophy; and also did a great deal of work in science. He invented the branch of mathematics
known as "coordinate geometry". It was his idea to measure the position of
a point by its distance from two fixed lines. So every time we look at a graph, we're looking
at something invented by Descartes. In fact, those two familiar lines
on a graph are known by his name. They're called Cartesian coordinates, 'Cartesian'
being the adjective from the name Descartes. His most famous works of philosophy are: The
Discourse on the Method, which was published in 1637, and The Meditations,
published in 1642. He never married, though he had an illegitimate
daughter who died at the age of five. He always had an eye to his own dress,
was proud of being an officer, and on the whole, preferred the company
of men of affairs to that of scholars. But during the years of his creative
work, he lived a very solitary life. When he was 54, he was prevailed on by Queen
Christina of Sweden, rather against his will, to go to Stockholm and
become her tutor in philosophy. It was a mistake. In the bitter Swedish winter,
he succumbed to pneumonia and he died in the following year, 1650. With me to discuss the work of this first
of modern philosophers is the provost of King's College Cambridge, Bernard Williams,
author of a well-known book on Descartes. Bernard Williams, I think the best way we
can begin is try and get clear in our minds what it was that Descartes thought was the
main problem he was gonna have to confront when he started.
Now, what was that? I think he'd been impressed by the education you
referred to and his experience and life around him, with the idea that there was no
certain way of acquiring knowledge. It looked as if there were some sorts of knowledge
around, but there was no reliable method by which people could advance knowledge. I think it's very important to put it in historical
context, that one realizes that science in our sense really didn't exist. I mean, the concept of science in our sense
as an organized international enterprise, with research methods, laboratories
and all that, simply didn't exist. And there was room for an enormous range
of opinions about what chances there might be of ever being a science.
I mean, on the one hand, there were people--and perfectly sensible
people--who thought that if you just found the right fundamental method, you
could solve all the fundamental problems of understanding nature in a very short while. For instance, Francis Bacon, the English statesman,
thought that you'd be able to get everything on the right road in a very brief period. On the other hand, there were people--skeptical
people--who thought that you couldn't find any knowledge at all, that there
wasn't going to be any knowledge. That everything was up for grabs, as it were. I think one particular reason--it's quite
important actually--why there was so much skepticism around, was actually
a result of the Religious Reformation. That after the Religious Reformation,
there were all sorts of claims made about how you found out religious truth, and they all conflicted with one another and
there was no way of deciding between them. And that gave rise to tremendous amount of
controversy in which people said--the enemies of all religions said--there simply isn't
a way of solving any of these questions. All these people disagree with each
other, you can't put it on a foundation. And then, religious people, reacting
against that in turn said, well, religion's no different in this or anything else. There isn't a way of putting
anything on a firm foundation. So skepticism was quite an important current
in the intellectual climate of Descartes' time, co-existing in an odd way with very extravagant
hopes of what science might be able to do. For instance, it might be able to do for mankind
through what we would now call technology. For instance, there were great hopes that
there could be a scientific medicine and scientific industry, and so on.
But nobody quite knew how to do it. For a fundamental innovator like Descartes,
the institutional setup must've presented problems, too, musn't it? I mean, almost every serious institution of
learning, or study, or teaching was in the hands of an authoritarian church, whose own
intellectual leaders were for the most part enthralled to ancient authority? That is certainly true. Of course, there were many different
religious influences, as we just said. I mean, one effect of the Reformation had
been that some seats of learning had more of a Protestant complexion, while obviously
those in Descartes' own Paris had a Catholic complexion, and so on. But of course, the point you mentioned
about authority is very important. Although there had been a good deal of research
into what we would now call mechanics, or a kind of mathematical physics in the Middle
Ages--and we shouldn't forget that fact-- a great deal of what would go by the way
of being science was actually in the form of commentary on ancient books. Above all,
though not exclusively, those of Aristotle. And one thing that Descartes and others of his
generation absolutely knew was that historical authority was not the same thing, as
if it were first order research or inquiry. So in other words, what one can say is that
Descartes, in starting out on his famous search for certain knowledge, was really looking for
a way of moving forward from the situation that you've just outlined. I mean, he was looking for a research program
as we might say in modern parlance, and prior to that, a research method. Yes, I think that's a perfectly correct
description of the situation. It's very important that one further fact
which conditions all of his work and which one finds the thread through it, was that
science was not conceived as a shared or joint, or organized enterprise, as it is now. For us, it's just taken for granted
that science means scientists. There are a lot of people, and
they communicate with each other, and there's a division of labor;
it's a division of intellectual labor. At that time, in the first half the 17th Century,
it was still a reasonable project for one man to have the idea that he could lay
the foundations of all future science. Descartes, who did really fundamentally believe
that--it was not, a piece of megalomaniac insanity on his part as it would be in the
modern world for anybody who had that idea. Now in my introduction to this discussion,
I said that Descartes became fascinated by the question of whether there was
anything that we could know for certain. He was clear from the outset that
certainty and truth are not the same thing. And that, to put it at its utter most
crudity: certainty is a state of mind and truth relates to the way
things are out there in the world. But he seems to have thought that you
could only know that you've got the truth if you also had grounds for certainty. So that his method was not only gonna have
to be one which delivered the goods in the form of worthwhile conclusions, but also
gave him a way of defending them against skeptical arguments. Now, how did he go about meeting
that double-barreled requirement? Well Descartes had a set of conditions on inquiry. Some of them were just sensible rules about
dividing questions up into handleable amounts, trying to get your ideas
clear and things like that. But he had got this very characteristic and
important rule for him that you shouldn't accept as true anything about which
you could entertain the slightest doubt. Now, of course, as you said, on the face
of it that isn't an immediately sensible rule. Because in ordinary life, we are constantly
seeking true beliefs about things, but we don't necessarily want to make those
beliefs as certain as possible. For one thing, we'd have to invest too
much effort into making the ultimately certain beliefs all the time. But Descartes, who was trying to get at the foundations of
science, and also not only the foundations of science itself in the sense of fundamental
general truths about the world, but also to lay the foundations of inquiry. That is, to be able, as he thought, to lay
the foundations of the possibility of going on to find out more things, to establish that
scientific knowledge was actually possible. For him, he felt that it was absolutely essential
that you should start the search for truth with a search for certainty. What he wanted to do was to be able to put
the scientific enterprise, as we would put it, into a shape in which it could no
longer be attacked by skeptics. So that, the first thing he wanted to do was to
engage in, we might call it preemptive skepticism. In order to put the foundations of knowledge
beyond skeptical reach, he said to himself, I will do everything the skeptics
can do, only better. And what I can do by pressing the skeptical
inquiry hard enough, is, he hoped, come out the other side with something which would
be absolutely foundational and rock hard. And one of the most characteristic features
of Descartes is not that he confuses the idea of looking for truth and the idea of looking for
certainty--he saw they were two separate things-- but he thought that the only sure way of searching
for truth was by starting by searching for certainty. And that led him to the
famous Cartesian doubt, as a method, not the
Discourse on the Method, that's about something else--but doubt used
as a method was fundamentally his message? Yes, he adopted something that
he called "the method of doubt". And indeed, the method of doubt is part
of the method which is discussed in the Discourse on the Method,
but only one element in it. Now the method of doubt worked, since
he was looking for certainty, by laying aside anything in which he could find a doubt. As he famously put at one point, it's like
having a barrel of apples and some of them are bad and some of them are sound,
you want to keep only the sound ones. So you take them all out first, look at them
one by one, throw away the ones that are dubious and put back only the absolutely sound ones. So he started by emptying
his mind of all beliefs, laying aside anything in which
he could see the slightest doubt. And the way he did that
was really in three stages. He started by laying aside things which
just on ordinary common-sensical grounds you might possibly find doubt. For instance, he reminded himself of such
well-known facts as sticks can look bent in water or things can look curious colors to you
if you have defects of eyesight, and so on. But he wanted to go beyond those absolutely,
everyday, kinds of doubt or grounds of doubt. The next step he took was to entertain the idea
that perhaps we could doubt that we were really awake and seeing things around us
as we ordinarily suppose. For instance, he just entertained the following
thought. He had often dreamt that in the past he was perceiving things. While he was dreaming--at the time he was
dreaming--he thought, just as he does now, that he was seeing people, or
tables, or whatever around him. But of course, he woke up and
found that that was all an illusion. How could he be certain that, at this
very instant, he wasn't dreaming? Well, that's a unnerving kind
of skeptical consideration. It had been used by skeptics before, but he
gave it an orderly, unsettled place in his inquiry. Now of course, the dream doubt, the doubt based
on the dream, does depend upon knowing something. It depends upon knowing that in the past you've
sometimes woken up and found you were dreaming. I mean, it depends on the idea that
you know something about the world. For instance that sometimes you sleep, sometimes
you wake, sometimes you dream, and so on. He then took another step. He said, I will imagine, I will go to
the most extreme doubt possible. I will imagine the idea of a maligned spirit, a sort of evil spirit, a malicious demon as it's
sometimes called in the literature, whose sole intent is to deceive me as much as he can. And then I put myself the following question.
Suppose there were such a spirit, is there anything he couldn't mislead me about? And this, of course, is a pure thought
experiment. It's an abstract thought experiment. We must emphasize that Descartes never
meant this philosophical doubt to be a tool for everyday living. He makes that point over and over again. The method of doubt, and in particular,
the fantasy or model of the evil spirit, is used only as a form of intellectual critique
in order to winnow out his beliefs and see whether some are more certain than others. And of course, the ultimate purpose for his
long-range strategy of winnowing away everything that he can possibly in any imaginable
circumstances doubt, is to find rock-hard indubitable propositions, which can then
function as the premises for arguments. Absolutely right. Well, there's two things. I mean, he certainly wants to find
rock-hard indubitable propositions. That's to say, the propositions which in some
sense of course requires a bit of inquiry into what exactly is, cannot be doubted,
which in some sense cannot be doubted which will resist the doubt. He wants them, in part,
as premises of arguments. He also wants them in some rather more
general role as to provide a kind of background which will validate the methods
of inquiry I was referring to before and we perhaps can say something
about how that works, yes. But now, after peeling away all imaginably
doubtable propositions, what are the utterly indubitable ones that he finally arrived at? Well the famous thing that he arrived at, what
some French commentators call the turning point of the doubt--it's where the doubt has
got to the end and it does a u-turn, and he starts coming back again,
constructing knowledge again. The point at which it stopped was the reflection
that he was himself engaged in thinking. As he said, the malicious demon
can deceive me as he will. He can never deceive me in this respect: Namely, to make me believe
that I'm thinking when I'm not. Because if I have a false thought,
well, that's a thought. So in order to have a deceived thought,
I've gotta have a thought, so it must be true that I'm thinking. From that, Descartes drew another conclusion,
or at least, he immediately associated with that another fundamental truth,
namely that he existed. And so his fundamental first proposition,
or two propositions really, was I am thinking, therefore I exist. Or cogito ergo sum, in the Latin formulation,
or as it's often called, "the Cogito". It's worth making the point that he himself
made it clear that by thinking, he didn't just mean conceptual thought, he meant all
forms of conscious awareness whatsoever: Experience, feelings, etc. Cogito, in this Latin formulation, equally
for Descartes' French formulations, means all sorts of things like perceptions, and
pains, and so on, not just--So it wouldn't be unfair to say that what he was saying
was: I am consciously aware, therefore, I know that I must exist. That's right.
Yes, that's it. He does actually, in the great work called
The Meditations, in which this is most carefully and elaborately set out, he does actually
show a great deal of finesse in pushing the boundaries of the Cogito forward step by
step through various kinds of mental experience. But some of what he gets to is exactly that. Now, in the process of peeling away everything
that can possibly be doubted in order to arrive at these fundamental, indubitable propositions,
he himself has shown that from these fundamental propositions, nothing follows. That although I am consciously aware,
I may draw all sorts of false inferences about for example, the external
world or whatever it might be, from whatever the deliverances
of my own consciousness are. So I'm conscious only--I mean I can be sure
--only of the fact that I am having whatever immediate experience it is that I am having. I can't be absolutely certain of any
inference I may make from that. Well, it depends on what sort of inference it is. What he thought was that the mere fact that
I have the experience, as it were, of being confronted with this table, for instance,
doesn't guarantee the existence of that table. I mean, that was got rid of even
at the dream stage of the doubt. And of course it's even more got rid of
by our friend, the malicious demon, who, maybe I might just have this
experience and nothing actually be there. So I can't immediately infer from my experience. What Descartes tries to do is to construct
now a set of considerations which will enable him to put the world back. Though it has to be said straight away that
the form in which the world is put back is rather different from that of common sense. We don't just, as it were, having moved all
the furniture out of the attic and because of the doubt, stuff it all back again
in a totally un-reconstructed form. We have a different view of the world when
we reconstitute it than we did in our everyday common sense experience. And incidentally, we'll come to how he
does that, but it's a very important fact about the method of doubt that that is so.
It's extremely important. Because sometimes people talk about Descartes'
doubt as if all he did, he had a kind of gratuitous doubt, and then, sort of put the
whole world back again afterwards. But it's very important that not only does
he put it back for very special reasons, but that what he puts back has actually been
subtly modified by an intellectual critique of how we can know things. But now, how he puts it back is--Yes, I was
gonna say that the point that I am concerned to get at now is that he seems, in arriving
at these indubitable propositions, to have painted himself into a corner. Because he's given himself indubitable propositions
which he himself has shown at a previous stage of the inquiry can't be used to infer any
certain truths about the existence of anything outside myself. Well, all he's seen at the earliest stage of
the proceedings is that the most obvious way of inferring the world from them isn't valid. He's now gonna give you a way which he claims is. Now of course, some people think that this
actually is a bit of a conjuring trick, and that he actually tries to get himself out of
the corner into which he's painted by the well-known hero of the thriller novel. You know,
likely, he threw of his bonds. But this is how it works. Now having, as you rightly say, got to the
point at at which it's only the contents of his consciousness which he is acquainted
with, there is nothing else available to him. It's obvious if he's going to put world back,
he's got to do it entirely out of the contents of his consciousness. So he's got to find something in the contents
of his consciousness which leads outside himself. And he claims that what this is is the idea of god. He discovers, among the contents of his consciousness, the conception of god. And he argues that this is unique
among all the ideas that he has, among all the things that are in his mind. This alone is such the mere fact that he has
this idea proves that there is really something corresponding to it. That is
to say, that there really is a god. That's a very difficult one for
many modern readers, isn't it? Of course. In fact, he has two different arguments, both
of which he uses in The Meditations for doing this. One is an old medieval argument called
the ontological argument, which is I think... Perhaps we needn't spend time on that.
That is, it's a kind of logical puzzle. I think it's metaphysical puzzle, but it's
much less characteristic of Descartes. The one that's really characteristic of Descartes
is the argument which says, I have this idea in my mind, but I see an absolutely
intuitive necessary principle. Which is the lesser cannot give rise to the greater. The lesser cannot be at the cause of the greater. Now my idea of god is the idea of an infinite thing. And although it's only an idea in itself,
it's nevertheless the idea OF an infinite thing. It involves the idea that I can
conceive an infinite being. But no finite creature, as I know myself to
be, could possibly have given rise to such an idea, the idea of an infinite being. It could only have been implanted in me
by God himself, has he memorably puts it at one point, as the mark
of the maker on his work. God, as it were, signed me by leaving
in this infinite idea of God himself. When I reflect that the lesser cannot give
rise to the greater in this way, I realize that since I have this idea of God, it can
only be because there actually is a God who has created me. So he's then put in the position of founding
our knowledge of the external world on a belief in the self-evidentness
of the existence of God. That's right. It's absolutely central. The next bit then goes that--it works like this. He then says, the things I know about this
God, I know that he exists, I know that he's omnipotent, I know that he created me,
and I know that he is benevolent. These are, of course, all
traditional Christian beliefs. And because God created me and is benevolent,
he is concerned as much with my intellectual welfare as with my moral welfare. And what that means is that if I do
my bit--and that's very important-- and I clarify my ideas as much as I should, and I don't dissent precipitously to things
I haven't thought out properly--if I do my bit in that sense, then God will validate the things
which I am then very strongly disposed to believe. Now I find that however much criticism I
make of my ideas, however carefully I think out what is involved in my beliefs about the physical
world and all that kind of thing, although I can suspend judgment in the doubt--I wouldn't
have got to this point if I couldn't-- While I can suspend judgment in this doubt,
I do have a very strong tendency to believe that there is a material world there. And since I have this disposition, I've done
everything in my power to make sure that my beliefs are not founded on error, then God will, at the end, as is it were, make sure
that I'm not fundamentally & systematically mistaken. That is, there is such a world. So, in other words, by ending up arguing, in effect,
that the world of science is given to us by a god whose existence is self-evident and whose benevolence
is self-evident, he's, so to speak, not so much answered the skeptics about science as
jumped over them. He's bypassed them. Well, what he says is that it's absolutely
essential to his position that he believes that these arguments that involve God will be assented
to by any person of good faith who concentrates on them enough. That's absolutely essential. He cannot accept--it would ruin his whole
position--if you accepted the idea that whether you believe in god is a matter of cultural
or psychological upbringing, and perfectly sensible people can disagree about whether
there's a god or not, however hard think think about it. It is essential to Descartes that to deny
the existence of God, confronted with these arguments, is as perverse and as totally
in bad faith as it would be to deny that twice two is four. And therefore, the idea is that if you lead
the skeptic properly through it, and the skeptic is an honest man and is not just mouthing
words or trying to impress, and you put these proofs before him, he must at the end assent. Now, people have not done this because
they have not thought hard enough. They haven't split it into, they haven't done
it in and orderly manner. A lot of the skeptics are, in fact, fakes
who simply go around making a rhetorical position and don't really think about it. But if you're in good faith and think hard
enough about it, then you will come to see this truth. And then you cannot consistently deny the
existence of the external world. That's what he believed. Now one very important outcome, which this
set of arguments had was that of positing a world which consists fundamentally of two
different sorts of entity. There's the external world, which is as it
were, given to me by a god on whom I can rely. But there's me, who is observing this external
world. And he made a great point, again in this earlier
stage of the argument, when he's stripping away all the propositions that he can possibly
doubt. Of saying that when he's considering himself,
and the nature of his self, he can even imagine himself existing without a body. But he can't imagine himself not
having the thinking awareness. Yeah that's that's the part about the
"I am thinking" being indubitable. So one consequence of that is that you get a
world posited which consists, on the one hand of thinking entities, which are
location-less and substance-less. And a world, a material world, which this
thinking entity is thinking about or observing. And it's a world of observer & observed,
mind and matter, spirit and material. Which has become built into the
whole Western way of looking at things. Now, Descartes' ultimate aim from the beginning
has been to establish the project of science or what we would call science,
a project of what we could call science. And by the arguments that you've outlined, he's
now arrived at a certain view of the external world. Now how is this external world
to be treated scientifically? Yeah that's--you remember I mentioned earlier
that when through the help of god we put the world back again, we didn't put back quite
the same world that we'd thrown away. That it's criticized in the process. And in our reflections, we come to the conclusion
that not only there is an external world, the external world, just as my essence
as a thinking thing is simply thought, the external world has an essence
too and that's simply extension. It simply takes up space, it's susceptible to being
treated by geometry & the mathematical sciences. All its, as it were, colorful aspects: The fact of its color, that there are certain
tastes and sounds, these are really subjective. They're on the mental side. They're subjective things that occur in consciousness
which are caused by this physical, extended geometrical world. He had an example which I think is worth mentioning,
it's a very good one, about a piece of wax. He said, if you take a piece of wax, it has
a certain size and shape in your hand. A certain color, smell, texture
feel, temperature, and so on. And it seems to us to be the
combination of those properties. If you put the same piece of wax in
front of a fire, it immediately melts. And then all those things change. Different color, different smell, different
temperature, different everything. And yet, we want to say it's the same wax. Now, what is there about it that's the same? Answer, I suppose, that there's a
continuous history of space occupancy. There is, as you know, there is a great--
one of the disputed things in expounding Descartes is what exactly he thought
the wax argument proved. And how much he thought it proved
just by itself. But he certainly did use that example to illustrate,
if not actually to prove, what he thought was the fundamental idea, that, as it were,
space occupancy, just being a piece of space. And it's really curious, he really did think a piece of space. He didn't think it was just a thing in space
because he didn't believe in a vacuum. He really did think that the whole world
was one extended item. And that separate items--things in it,
as we say, tables or whatever--really are local pieces of this in certain states of motion. Now this, as a foundation for the mathematical
physics of the 17th century, in its own terms, didn't come off. I mean, eventually it was going to be replaced
by the classical physics and dynamics of Newton which had a different conception
of a mathematical world. But it did a tremendous amount to establish
the notion of a physical world which is fundamentally of a mathematical character, and permits mathematical physics to be done. Because it was one of the most important and
striking facts about the Scientific Revolution starting in the period we're discussing, in
Descartes' lifetime and through his work, is that the first of the great sciences, as it were,
to get going was in fact mathematical physics. Chemistry--the things that deal with sorts
of things in much more of that kind of detail, is of course much more a product of the
18th & 19th century, not of the 17th century. But wouldn't it be fair to say that Descartes,
in his time, did more to launch the possibility of science and to, as it were, sell science
to the educated public than anyone else? Yes, I should've thought that was probably true. I mean, the figure who was also enormously
famous, and as a matter of fact whose actual physics is nearer to classical physics as
it came out in the end, is actually Galileo rather than Descartes. But of course, Galileo was more notorious perhaps
than respectable, because he was tried and condemned by the
Inquisition and so on. Yes, Descartes' intellectual influence
in this respect, was simply enormous even though the details of his physics
were eventually to be in good part repudiated. Now up to this point in the argument, what
Descartes has shown-- Descartes hasn't, as it were, provided us with any physics. What he's shown is that a mathematically
based physics is possible and is applicable to the real world. Can you expand on that distinction a little? Yes, absolutely. What he hopes to have shown by the maneuvers
we've been through, we've followed so far, is that, as it were, the world is so constructed
that man is capable of knowing about it. I mean, in that sense, man and the world
are made for each other by God. There is still a teleological thing
at the end in God. Even though, of course, man in his essence
is not actually part of nature, because man is this immaterial, intellectual
substance, which isn't part of the natural thing. Man is not part of nature in that sense,
but he is, as it were, his intellection is quite well adjusted to it. And that means we can conduct
a mathematical physics above all. Now Descartes thought that some of the fundamental
principles of physics could themselves be known by what we would call philosophical reflection. He thought, in particular, we could know
by such reflection that every physics had to have a conservation law. There had to be something that was conserved. We talk about the conservation of energy,
the conservation of force, and so on. The indestructibility of matter, as it used
to be--Yes, as it used to be called. Of course, now we know the equivalence of
matter and energy through atomic reactions, and so on. Now, Descartes actually picked on the quantities
that was conserved, something which wasn't what was conserved, and indeed in terms of
classical physics, later it's not even well-defined. But the idea was there. That was a priori
all right, was to be known by reflection. Further details of the laws of physics,
he thought required investigation. And in particular, how the
world was actually laid out, how different patterns of motion were
to be founded, he thought was a matter for experimental inquiry. Now this is quite importan, because Descartes
is rightly said to be a rationalist philosopher. That is, he thinks that fundamental properties
of the world and of the mind and so on, can be discovered by reflection,
by a kind of philosophical reflection. And he does not think that everything is just
derived from experience or experimental things. It's sometimes supposed that he was such
a strong rationalist that he thought that the whole of science was to be deduced by purely
kind of mathematical or logical reasoning, from metaphysics. That if I sat and thought hard enough about
the Cogito and God and matter and all that, I'd arrive at the whole of science. He thought no such thing. In fact, he's absolutely consistent always
in saying that experiments are necessary to distinguish between some ways
of explaining nature and others. You can build different models. This is very modern, a very
modern aspect of his thought. You can build or construct different
intellectual models of the world. Within his laws, experiment is needed
to discover which are truly there. And is experiment seen by him
as designed to test the answers? Or to give us the material for
the premises to our argument? It's designed for a number of different
things actually, but really the following. If you take the fundamental laws of nature,
the principles on which matter moves, there are a lot of different mechanisms you
could imagine which would produce superficially the same effect. You then make differential experiments. You then arrange a setup which one thing
will happen if one model is what's really there and it won't if another is. And so you select between models. And that really is a quite a good description
of quite a lot of what physicists do. Well it's the modern notion of the
crucial or decisive experiment. Yes and he was very keen on that. One of the things that Descartes was admiral
about was that it was simply no good blundering around the world, trying out experience
to see what you could find out. You had to ask the right question. And that's again this thing we're
saying before, that God is on your side If you do your bit. God will not allow you
to be systematically deceived if you don't systematically deceive yourself. So what you've got to do is to think
of the right questions to ask. And then God will assist nature
in giving you the answer. I think it's worth making the point at this
stage in the discussion that although God is an absolutely indispensable element to
Descartes in the course of arriving at his method, once you've got the method, you don't have
to be any sort of believer in God to use it. Yeah. That is an exceedingly important point. Descartes wanted to free the process
of science from theological constraints or foundations. Or as one might say, free it from theological
foundations & hence from theological interference. But, of course, he was extremely keen to say this
does not mean that we produced a godless world. We've produced a world which is, in fact, made by
god, where our knowledge of it is guaranteed by god. The way you have to appeal to God in your
intellectual life, is not in, as you rightly say, in conducting science, but in proving
to skeptics that it can be conducted. And Descartes, very sensibly thought
you shouldn't spend a lot of time proving to skeptics that it can be conducted.
You only need to do it once. He thought he'd done it. Now
let's all get on with it, was his view. Now one phrase that's commonly used for an
aspect of this whole system that he provided us with is Cartesian dualism.
We've talked about this already. You mean the mind body dualism? Yes the division of total reality
into spirit and matter. Yes. Now didn't this give him a theoretical
problem of a very important kind? How did he explain the interaction? I mean, to put it very crudely: how is a spirit
able to push objects in the world around? Well, I'm afraid, frankly, that the
answer is that he never really did. Leibniz somewhat scornfully said on this subject,
the interaction, he said Descartes seemed to have given up the game,
so far as we can see. He did have a theory in the later work, just
before he went to Sweden, he wrote a book in which he did curiously try to localize
the interaction between mind and body in the pineal gland, which is in the body
at the base of the brain. But, of course, it barely even makes sense. I mean, the idea that this purely, sort of
abstract non-material item, something which is almost, though not quite, as it were, the
counting of a number, could induce a change in the physical world by redirecting certain
animal spirits, which is what he believed, is so difficult to conceive, even
in sort of abstract principle, that it was a kind of scandal for everybody. I mean, a lot of the philosophy of the 17th
century, and indeed subsequently actually, addressed itself to trying to find
some more adequate representation of the relation of mind and body
than Descartes actually left us with. Nevertheless, some form of Cartesian dualism--
of distinction between observer and observed, subject and object, got into Western thought
for something like 400 years. Well, I think the distinction between subject
and object, known and known, is the distinction which is simply impossible for us to do without. There are indeed philosophical systems
that constantly try to say that we simply have no conception of the known
independently of the knower, we make up the whole world and so on. But of course, the trouble about that is that
it's very difficult--well, complete idealism, the idea that everything that's there is really a
product of our minds, is, to put it a little simply, quite difficult to believe. We all do and certainly all the science does
depend very much on a dualism between the knower and the known, a world which we can know independently
of our process of knowing it. What, I think, very few people now assent to
is the absolute dualism between the completely pure mind and the body. The knower has to be seen as indeed, of course
it was in philosophy earlier than Descartes, for instance by St. Thomas or by Aristotle,
the knower has to be seen as an essentially embodied creature, him or herself, as it were. And not just as a kind of pure soul. What would you say its main influence
on Western philosophy has been? I mean, Descartes' influence has
been simply immense, and still is. Well if you summarize it in one thing is that
is that Descartes, and almost Descartes alone who brought it about, that the center of Western
philosophy for all these centuries has been the theory of knowledge. The idea that philosophy starts
from the question: What can I know? Not from the question just "what is there?" or "how is the world?"
but "what can I know?" And not just "what can I know?"
but "what can *I* know?" That is, that it starts from a
first-personal, egocentric question. And it is very important for the structure
of Descartes' system--I mentioned right at the beginning that it was possible in his
time to think that perhaps science could even essentially be done by one person. But even if you lay that historical context
aside, it is a very important part of his enterprise that it is autobiographical. It's no accident that his two great works,
The Discourse on the Method, and above all, The Meditations, are written
in the first person. They're works of philosophical self-inquiry,
and this first-personal and epistemological aspect, that is the aspect concerned with the
theory of knowledge, has been the overwhelming influence of Descartes. Now, given that all that are wrong with the
philosophy that we've touched on, and of course there are more than we have touched on. And given that the central concern of philosophy
has now moved away from the problem of knowledge, which was made central by Descartes,
why is the study of Descartes now as valuable to us as it is? I mean, if I may put this question in a personal way: you,
Bernard Williams, you've spent, as far as I know, almost 20 years of your life
working on a book on Descartes. You must've thought this enormous investment
of yourself and your life was worth it. Why? I think for two reasons... Let's lay aside the purely case of historical
understanding the role that Descartes has played in getting us into our present situation, where I think that just to know what he said
in a little bit of detail is very important simply to understand who we are
and where we've come from. But the reason why I think that this book
--when I say this book, above all, I mean the particular book called The Meditations--is
a book that one very much, if one is interested in philosophy wants to read now, is because
the path it follows, the path of asking "what do I know?", "what can I doubt?",
and so on, is presented in an almost irresistible way.
And the point is, it's not an accident that this emphasis in
philosophy has been so overwhelmingly important. It isn't that Descartes, just because he was
a dazzling stylist or something of that kind, could kind of perform a long-distance
mesmerism on the mind of Europe. That isn't the reason. The reason is because he discovered something
which is intrinsically compelling. That is, the idea that can I ask myself: well
I have all these beliefs, but how can I get around behind my beliefs
to see if they're really true? How can I stand back from my belief
to see which of them are prejudices? How much room for them in skepticism? These are really compelling questions. And it needs an enormous amount of philosophical
imagination and work to get oneself out of this very natural pattern of reflection. And another very related question, which comes
before you very dramatically in this extraordinarily written book, is not just "what can I know?" because as we discovered
already in the Cogito "what am I?" We can imagine ourselves--we have
this power of the imaginative extraction from our actual circumstances. We can imagine ourselves looking out
on the world from a different body. We can imagine looking into a mirror
and seeing a different face. And what's important, looking into a mirror and
seeing a different face, and not being surprised. And this gives us the idea, a very powerful
idea, that I am independent of the body and the past that I have. And that is an absolutely foundational experience
of the Cartesian idea, that I am somehow independent of all these material things. Cartesian dualism, though once you look
at it sideways as a theory, it's immensely difficult to believe for the
reasons that we've touched on. It's also that it's almost impossible to resist
if you go at it through a certain set of reflections. But I think the set of reflections that Descartes,
with unexampled clarity and force, laid before you to lead you down that path--as I think,
mistaken path--are so not only powerful themselves, but as it were, near to them both, that it is a prime philosophical task to try
and arrive at an understanding of oneself, one's imagination, one's conception of what
one might be, that one would free one of that dualistic model. Thank you very much.
