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8 Descartes, Principles I.1-23 the demonstrations are so certain
that even if our experience seemed to show the opposite, we should still be
obliged to have more faith in our reason than in our senses. – Descartes, Principles of philosophy, Part II,
Article 52
This quest for
foundational principles is one of the characteristic features of Descartes’s philosophy.
Other philosophers have been willing to settle for less — for
probability or for provisional suppositions that, while not certainly true,
can be confirmed by sensory experience.
However, Descartes’s conception of the
proper method for gaining knowledge left him with no choice but to make
stronger demands. The first rule of
his method dictates that we start with axioms, and the third rule stipulates
that all knowledge is to be obtained by deduction from these axioms. The Descartes who had gone traveling to
read the book of the world and learn lessons from experience had concluded
that if mistakes are easier to discover in practical matters than in
speculative ones, then the thing to do is not to turn to practical matters
but to make sure that the foundations for your speculations are absolutely
firm — so firm that they could stand even in the face of contrary sensory
experience. It bears noting in this
context that Descartes was confident of the truth of the mechanist natural
philosophy, which postulates that the real world looks very different from
the coloured, scented, warm and cool bodies we experience through our
senses. He therefore expected that
when he proceeded in accord with his method, his deductions from axioms would
establish the existence of things that are very different from what we see
around us. But for Descartes, the fact
that deductions from our theories might come into conflict with everyday
experience or with common sense is not by itself a reason to think that the
theories are wrong. He did not pretend
to verify his principles after the fact, by reference to their
consequences. Instead, he sought to
ground them in absolutely certain first principles. Descartes’s first
order of business was to find such principles. QUESTIONS ON THE
1. Why should
we think that we are the victims of prejudices or “preconceived opinions”
that have kept us from knowledge of the truth?
2. What is the
“scale” of the doubt that Descartes proposed in Principles I.1? What things
does he propose to call into doubt and what things would he consider to be
above doubt?
3. What is
called into doubt by the fact that our senses sometimes deceive us and by the
fact that there is no certain way of distinguishing being awake from dreaming?
4. Should we
doubt principles that are revealed to us by reasoning? If so, why?
If not, why not?
5. What are
the limits of human freedom?
6. What makes
my existence certain (beyond all possibility of doubt)?
7. What am I
certain of when I claim to be certain of my own existence? What else, besides myself, am I certain of
insofar as I have this certainty of my own existence?
8. What is
“known by the natural light?”
9. What
determines that there must be some substance in existence? 10.
What makes our knowledge of a substance
“clear” 11.
Why do we find more attributes in our minds
than in anything else? 12.
Where does the power of sense perception
reside? 13.
What makes it of paramount importance for us
to determine what ultimately caused us to exist? 14.
Under what conditions is it possible to doubt
the results of demonstrations? 15.
What is contained in the idea that the mind
finds in itself of God that guarantees that the object of this idea must
necessarily and eternally exist? 16.
Why must we conclude that the supreme being does exist? 17.
In what way are ideas different and in what
way are they all alike? 18.
What is required to give someone the idea of
an intricate object? What assures us
that this must be so? 19.
How can we have an idea of supreme perfections
if we are ourselves imperfect? 20.
Why must the whole world be continually
recreated from one moment to the next? NOTES ON THE Principles
I.1-3. The
method of doubt. Principles I.1 opens by proposing that
we reject everything we have up to now supposed to be true and set about
rebuilding the edifice of our knowledge on new foundations. To justify this proposal, Descartes noted
that we all began life as infants with very rudimentary cognitive
abilities. Probably, our sense organs
worked as perfectly at birth or shortly after as they do now (if not
better). But our minds were so
underdeveloped and the range of our experiences so narrow that we were in no
position to make correct judgments about what we were experiencing. We nonetheless did so, having no other
choice. In the process we arrived at
such incorrect (to Descartes’s mind) views as that
the objects of our experience actually possess the qualities of colour and
heat that they appear to have, that there are empty spaces, and that we are the
bodies our senses reveal to us.
Growing up with them, these judgments became habitual, and gradually
turned into prejudices, only confirmed by the customary opinions of those
around us, who had grown up in similar circumstances. They came to us to seem so
natural and obvious as to be certainly true.
But as basic as such truths may seem, surely, we ought not to trust to
such a haphazard way of arriving at them.
Even apart from traveling and discovering how different the practices
and opinions of others are concerning other things that we take to be equally
natural and evident, we ought to think that it is a mistake to trust to
juvenile habits and conceits. We ought
to at least once look carefully within ourselves and consider what is really
certain and evident, and what is only customary and habitual. The best way to draw the distinction is to
ask ourselves what is beyond all shadow of a doubt. Whatever emerges as being beyond all shadow
of a doubt could surely be no immature preconception, but would have to be a
sound judgment. Since most of what we
know is based on sense experience or reason, Descartes first considered the
reliability of what we have come to know on the basis of these two
“principles.” The results that he came
up with were devastating. Principles I.4-5 offer
two powerful arguments for doubting what we have learned from sensory
experience and what we have discovered by reasoning. These arguments are commonly referred to as
the dreaming argument and the deceiver argument. Principles
I.4. The
dreaming argument. Prior to
Descartes, philosophers wishing to question the reliability of sensory experience
had commonly appealed to a set of arguments known as the sceptical
“modes.” Sceptics would employ the
“modes” to show that one and the same object can appear differently to
different animals, to different human beings, to different sense organs, to
the same sense organ under different circumstances, and so on. This would hopefully convince the listener
that we have no direct knowledge of the nature of objects, but only of
appearances, and that the appearances of one and the same object are so numerous
and different that there is no way of telling what it is really like. But Descartes had
little use for the sceptical modes.
While he did note that our senses have from time to time presented
objects as being different than we have reason to think they really are, he
never put this point by claiming that they leave us with no way of deciding
which appearance is the correct one.
He only took things so far as to say that our senses “sometimes”
deceive us, suggesting that the deception is merely occasional and temporary,
and that further sensory experience serves to uncover the error. This still leaves us with some grounds to
doubt sensory experience. Since our
senses have deceived us in the past we can wonder, on any given occasion,
whether they might now be deceiving us and whether further experience will
uncover some error. But the progress
of our experience leaves us with no reason to think that our senses might be systematically deceptive — that they
might deceive us so consistently as never to bring up anything that would
lead us to notice the deceit. There is a different reason
to think that our senses might be systematically deceptive: the possibility
that we might be dreaming. Descartes supposed
that I have no way of definitively ruling out the possibility that I might
now be asleep and dreaming. The fact
that my current experiences are rich, detailed, and vivid does not prove that
they are not dreamed up since I have in the past had dreams that are rich,
detailed and vivid. Or, at the very
least, I can well conceive it possible that I might have such a dream. Similarly, the fact that I now seem to remember
a continuous, coherent past, reaching back for many years and consisting of
events that are uniformly ordinary and law-governed does not prove that I am
not now dreaming. For, even though
many dreams are incoherent, this is not the case with all dreams. Dreams can be as coherent as waking
experiences and sometimes they can include dreamed up memories of a long,
coherent history. At least, it is
possible that some dreams could be like this.
And as long as it is possible we cannot claim to know beyond a shadow
of a doubt that dreams cannot be internally coherent and plausible. Even the memory of having awakened is no
sure indication I am not now dreaming, since I have had (or can well think it
possible that I could have) dreams in which I dream that I wake up from a
dream within the dream. In general, it
seems that any criterion anyone might care to use to try to distinguish
dreams from waking experience could be undermined by the objection that we
might just dream that the criterion has been met. We might think that,
despite these possibilities, we are pretty good at telling the difference
between reality and dreams. But for
Descartes, being pretty good at determining the difference is not good
enough. We need to be absolutely
certain. As long as it is possible
that we might be dreaming, we cannot claim to know for sure that we are not
dreaming, even now. But if I grant that
there is no way of definitively ruling out the possibility that I am now
dreaming, then doubts about the actual existence of everything revealed by
sensory experience follow as a consequence.
Since things experienced in a dream are generally false, having no
good way to determine that I am now awake means
having no good way to determine that there is any actuality reflected in my
current experience. I cannot say that
simply because I am seeing this page with these words printed on it, that
therefore there must actually be a page with these words printed on it. More radically, I cannot say that simply
because I see myself surrounded by the walls of this room, in this building,
in this city, in this country, that any such room, building, city, or country
exists. There may not even be a planet
Earth or a universe like the one I now think I remember seeing when I last
looked up at the stars at night.
Perhaps I am a being on a planet in another world who is merely
dreaming all of these things and none of them actually exists, and in a
moment I will wake up and discover my error.
Indeed, perhaps there is not a corporeal, extended world of any kind. After all, setting aside the minority
opinions of Hobbes and Epicurus, people have for centuries believed in the
possibility of the existence of immaterial spirits like ghosts and
angels. These are things that exist
without having physical bodies. What
is to say, therefore, that I might not be a sleeping angel, merely dreaming
that it has a body? Just as the dreaming
argument should lead me to doubt whether I really have a body, and whether
the surrounding world is at all like what I perceive it to be, so it should
lead me to doubt whether there are any such things as the atoms and
corpuscles imagined by the mechanical philosophers, or the forms and
qualities imagined by the Aristotelians, or even the other people that we all
imagine to inhabit our world.
Similarly, it should lead me to doubt whether any of the sciences that
describe these things, such as physics, cosmology, and metaphysics are
true. After all, just as I may be an
angel dreaming that it has a body, so I may be an angel in an aspatial spirit-world dreaming it is located somewhere in
a world of bodies. Indeed, I may be a
single, solitary spirit, the sole thing in creation, dreaming that there is a
world of extended bodies and other minds around it. Principles I.5. The
deceiver argument. What, then,
about the sciences that don’t set out to describe anything that actually
exists, but that deal with merely ideal things, sciences like arithmetic and
geometry? Even here there are reasons
for doubt. Descartes noted that we
sometimes make mistakes in simple arithmetic even in waking life, as anyone
who has tried to balance a check book knows only too well. As with the case of occasional sensory
deception, we might object that such mistakes are generally a product of
haste and inattention, and can be revealed by proceeding more carefully and
pausing to make frequent reviews of our calculations. But once again there is a reason to think
that our demonstrations and calculations might be not just occasionally but
systematically deceptive. It is possible
that in his younger days Descartes may have attended the Loudun
witchcraft trials and been impressed by the efforts of the defence attorneys
to argue that if the Devil was as powerful as the Prosecution claimed he was,
then he ought to be able to deceive the Court and the Judges into thinking
that innocent people are witches.
Whether that is the case or not, the thought occurred to Descartes
that, if a being powerful enough to have created the world exists, then that
being ought to easily be able to ensure that every time I add two to three I
come up with the same, wrong result. A
really powerful deceiver should be able to convince me that two plus three is
six. After all, I do occasionally make
this mistake all on my own, so a deceiver should be able to make me make it
systematically, and so foul up my entire knowledge of arithmetic. This may be an
extravagant possibility, but for Descartes, any reason for doubting a claim,
however wild or extravagant, is a reason for setting that claim aside and
going on to look for something else that might offer more certainty. And so our reasoning in geometry and
mathematics must be rejected as well as our sense experience of ourselves and
the world around us. Principles
I.9,
I.6, I.10. Residual certainties. Descartes
went on to claim that there remain certain things we cannot bring ourselves
to doubt, even in light of the fact that we might be dreaming or that a
supremely powerful and resourceful being might be bending all its energies on
attempting to deceive us. The possibility that
we might be dreaming only puts us in a position to doubt the actual or external existence of the objects we encounter in
dreams. It does not put us in a
position to doubt our experiences themselves.
There might be nothing in existence that corresponds to what we think
we are experiencing, as is in fact the case in a dream. The objects we think we see around us might
not exist. The objects that do exist
might be nothing like those that we think we see around us so that nothing
anywhere exists or ever has existed that resembles what we think we see
around us. We ourselves might not have
the bodies we think we have or might perhaps be entirely disembodied. Yet, all the same, even if we are dreaming,
there are certain ideas or thoughts
in us, and it seems impossible that we could be mistaken about that. I cannot doubt that I am thinking of a red
square without thinking of a red square.
Even a supremely powerful deceiver could not deceive me into thinking
that I am thinking of a red square without giving me the thought of a red
square and thereby making it true. So it seems that all
that the dreaming argument can lead us to doubt is that there are things
currently located at places outside of us that are something like what we are
currently experiencing. But we cannot
doubt the existence of our current experiences themselves, considered just as
experiences. At this level, even sensory
experience is beyond doubt. If I think
I am sensing a printed page, at least the sensory experience of a printed
page must exist in me, even if no printed page exists in the world outside of
me. There are also
limitations on what the deceiver argument can lead us to doubt. To see why, I first need to draw a
distinction between things we know by reasoning and things we know by what I
will call intuition. Things we know by
reasoning are the conclusions we draw from argument or demonstration. But there are some things that we know (or
think we know) without argument. When
we see something, we think we know it.
Of course, we have learned to doubt that what we see might actually
exist outside of us. But when we see
something we at least cannot doubt that we are seeing something — that we are
having some perceptual experience, even if it is only ideas in us. We cannot doubt that we have thoughts in
general. Similarly, we cannot doubt
that each thought is something and not nothing. And when we have a particular thought, we cannot
doubt that it is that thought rather than some other. We cannot doubt that each thought is what
it is and is not anything else. Since
each thought is what it is and cannot be otherwise, we cannot doubt that red
is different from green. Moreover, we
cannot doubt that orange is more like red than it is like green. Because each thought is what it is and is unlike
any other, we can compare our different thoughts with one another and simply
“see” that there are certain relations between these thoughts. Many of these relations (for example, similarity
and contrast, degrees in quality, differences of quantity) are what they are
and cannot change without the ideas themselves changing. This is what I mean by talking about an
intuitive grasp or conviction. An
intuitive grasp or conviction is the kind of grasp or conviction we get when
we contemplate our own ideas and just “see” that they stand in certain
relations to one another. We do not
demonstrate these things by reasoning or argument. They are rather the fundamental
indemonstrable premises on which all reasoning is based. Neither do we see these things with the
eyes of our body in the light of the sun.
We rather see (or better “intuit”) them with the eyes of the mind in
what Descartes liked to call “the light of nature” or “the natural light.” Let me return from
this digression about reasoning, perceiving, and intuiting to discuss the
limitations on the deceiver argument.
We can imagine two ways in which a deceiver might deceive us. The deceiver might make us perform demonstrations
and calculations incorrectly every time we go to perform them, so that we
never notice our mistake.
Alternatively, the deceiver might simply force us to believe certain
absurd things, even apart from any proof.
Descartes was certainly concerned about the possibility of a deceiver
who works in the first way, and leads us to systematically mistake the
results of demonstration. But what
about the second? Interestingly, we
know for a fact that we are not compelled to believe just anything. There are surprisingly many things we can
bring ourselves to doubt, as this very course of argument we have been
engaging in proves. But there are also
certain things that it seems it is simply not within our power to doubt. These things are not the conclusions of
reasoning or demonstration. We have
been able to convince ourselves to doubt those. Neither are they
the things we think we perceive to exist in the world outside us. We have been able to convince ourselves to
doubt those as well. They are instead
the intuitively obvious relations between ideas I spoke about earlier. Descartes noted that,
even if there is a deceiver, it is intuitively obvious that the deceiver has
left us with a great deal of freedom to either accept or deny or doubt many
things. It is also intuitively obvious
that there are certain things we cannot doubt — whether there is a deceiver
or not. If the deceiver is forcing us
to believe these things even though they are really false or absurd, then our
situation is hopeless, because we don’t even have it within our power to
doubt them, even knowing that this is a possibility. But could it even be possible for a
deceiver to trick us about such things?
Or are the limits of our freedom in this regard are a reflection of
what it would be impossible for even a supremely powerful deceiver to bring
off? If I intuitively grasp that red is
not green, how could a deceiver deceive me about that fact other than by
giving me ideas of red and green that are as a matter of fact different from
one another, and thereby making it true after all? These reflections led
Descartes to conclude that if you really do intuitively grasp something — if
what you know is the product of your immediately intuiting the presence of a
certain relation between your own ideas — then there is no way even a
deceiver could trick you about that.
This is the limitation on the deceiver argument. It can lead us to doubt the conclusions of
reasoning or demonstration. But it
cannot lead us to doubt what is immediately or intuitively evident as a “first
truth” independently of all argument. Of course this raises
a question: how do we know for sure that we are really intuitively grasping
something rather than simply falling back on some juvenile
preconception? But there is a ready
answer. If it really is intuitively
grasped, it will be impossible for you to bring yourself to doubt it —
impossible because, being an immediately perceived relation between ideas,
you will see that there is no way that relation could fail to be there
without the ideas being changed. In
other words, if it is intuitive, it simply cannot be thought of in any other
way. If you can even conceive of it
being different, it is not intuitive, and you are not forced to believe
it. And if you can conceive of any
means by which you might have gotten it wrong, it is not intuitive, and you
are not forced to believe it. We are
not forced to believe even the results of simple demonstration, like 2+3=5,
because we sometimes get those results wrong and because this means that
wherever a chain of inference or argument is employed a deceiver could
systematically trick us. But even a
deceiver could not make us think that a circle is not a square without giving
us ideas of a circle and a square that look different from one another, and
so making it so. Principles
I.7-8 and I.11-12. Self-certainty
and the distinction of mind from body.
For Descartes, our thoughts and the intuitively evident truths that
are very clearly and distinctly revealed by comparing those thoughts with one
another are not the only things that survive the dreaming and deceiver
arguments. More famously, and even prior
to these other items, he also maintained that it is impossible for me to
doubt my own existence. As he put it
at Principles I.7, “we cannot for
all that suppose that we, who are having such thoughts, are nothing. For it is a contradiction to suppose that
what thinks does not, at the very time when it is thinking, exist.” This further
conclusion is less full blooded than it might appear because it begs a large
question: what exactly am I supposing to exist when I suppose myself to
exist? As Descartes was at pains to go
on to stress, all the doubts that arise from the possibility that I might be
dreaming remain in force, which means that anything that I might be merely
dreaming myself to be can be doubted.
I can’t doubt my thoughts, because even if I am dreaming I must be
having those thoughts if I am dreaming them.
But I could be an amputee dreaming they still have the missing limb
or, more radically, an angel dreaming it has a body. So I can’t identify myself with my body. Descartes fingered
this result as a preliminary indication of one of the principal points he
wanted to establish. If I can doubt
that I have a body while nonetheless being certain that I exist, this suggests
that I might in fact be something quite distinct from that body that I have
since youth identified myself with.
Though the dreaming argument should have convinced me that I cannot be
certain of the existence of an external world or even of my own body, this is
not the same thing as convincing me that I cannot be certain of my own
existence. After all, why should I
think I need to have a body in order to exist? Hobbes had wanted to maintain that the
notion of an incorporeal substance makes no sense, but Descartes considered
that the fact that I cannot doubt that my thoughts exist, while I can doubt
that I have a body, is the best argument for a radical distinction between
the two. Mind and body are two
entirely different things, the one in no way depending on the other. The other grounds for
doubt fare no better. Might I just be
dreaming that I exist? Then I would
have to be there to do the dreaming. Might
there be a deceiver who tries to trick me into believing that I exist when in
fact I do not? But how could the
deceiver set out to deceive me unless I exist to be deceived? So the belief in my
own existence is certain because it resists all attempts to show that it is
uncertain. All the same, if I am
not my body, what am I over and above just a collection of thoughts? Descartes wanted to claim
that I am something more. I am a thing
that has these thoughts, so that
thoughts may be defined as “happenings” that occur “within” me (Principles I.9), or as attributes or
qualities of some substance and I, considered as a substance, can be
understood to be a characteristically or “essentially” thinking substance — a
thing whose nature it is to think.
This is something of a leap. It
is moreover, a leap in a very odd direction for an early modern philosopher,
concerned to reject an Aristotelian or Scholastic world view because it
invokes the old, Aristotelian picture of the world as a collection of
“substances” that possess “qualities.”
But Descartes considered it to be at least as evident that I am a
thinking thing as that my thoughts exist — indeed, even more evident. To further buttress
this position Descartes appealed to an intuitive truth that, he claimed, “is
very well known by the natural light” (Principles
I.11): that “nothingness possesses no attributes nor
qualities.” As thus stated, this
certainly appears to be the sort of principle that it would be impossible to
deny. There is nothing to nothing. But Descartes meant to employ a rather more
robust, contrapositive version of this principle:
that where there are attributes or
qualities there must necessarily be some thing or substance in which those
attributes or qualities inhere. This
is to presume that there can be no “free floating” attributes or qualities,
and why should we accept that? More to
the point, Descartes wanted to claim that because we find ideas of all things
within ourselves, we must know ourselves better than we know anything else,
because things are known through knowing their attributes or qualities and
while we can doubt that these ideas or qualities represent or inhere in
anything that exists outside of us, they are certainly attributes or
qualities of ourselves. But why should
we reduce thoughts to attributes or qualities of things rather than consider
them to be things in their own right? Descartes’s answer to
both of these questions would have been the same: these are intuitively
evident first principles, evident to us “in the natural light.” When we examine our ideas we simply see,
indubitably, that they are imperfect or dependent things that could not exist
on their own but that must be “happenings” that are contained “within”
something else. And we just see that
this is a special case of the more general rule that attributes or qualities
must inhere in some substance and that substances are known as things that
possess attributes and qualities. We
see these things so clearly that they cannot be doubted. This is not the only
occasion on which Descartes appealed to a “natural light” that reveals common
notions to us. Just in this one
reading section there are two others, at Principles
I.18 and I.20. In those places,
appeals to the light of nature play an important part in proofs for the
existence of God. And there are many
other appeals to the light of nature both in the Principles and in Descartes other works. It would not be entirely inappropriate to
suspect that Descartes abandoned his method of doubt on these occasions and
appealed to the natural light as an oracle, capable of revealing things that
could not otherwise be known. However,
a more charitable reading, based on Principles
I.6, would have it that the method of doubt is what enables to distinguish
between what is really known by the light of nature and what is only the product
of juvenile preconceptions. If it is
really known by the natural light, we have no freedom to doubt it. If it is not, we can. Descartes maintained that we cannot doubt
that qualities and attributes must inhere in some substance. As we will see, later early modern
philosophers were not so sure. Principles
I.13-23. Arguments
for the existence of God. In
addition to being certain of the existence of himself as a mental substance,
Descartes claimed that we can be certain that there must be a God (and so,
incidentally, that there could not
be a deceiver, which opens the door to being assured of the results of
carefully and repeatedly performed demonstrations and calculation after all,
and even to placing some trust in sensory experience). He devoted considerable attention to this
important enterprise and over the course of Principles 13-23 offered three arguments for the existence of
God, presenting each later argument as a kind of support for the earlier
one. The arguments are just what they
would need to be: arguments that take off from what Descartes considered to
be established beyond any doubt: first, the ideas of his own existence within
himself, and second the ability to appeal to certain intuitively evident
first principles concerning relations between those ideas. Since the existence of an external world is
at this point still in question, Descartes’s
arguments are not cosmological or teleological arguments — arguments that
attempt to prove that God must have existed as the first cause or designer of
the world around us. The premises are
lacking for such arguments. Instead
the arguments appeal exclusively to what we are able to find within
ourselves. Principles
I.14-16. The ontological argument. Descartes’s first argument for the existence of God is
based just on appeal to the ideas we find within ourselves and does not rely
on any intuitive truths. Among the
ideas we find within ourselves is an idea of God. And just as, by inspecting ideas like those
of a square or a triangle, we can simply perceive that a square has four
sides and a triangle three, so, Descartes claimed, when contemplating the
idea of God, we can see that such a being must necessarily exist. Our idea of God is the idea of a supremely
perfect being. But, according to
Descartes, existence adds to the perfection of a thing. This is proven by the fact that, if you
were offered a choice between having ten actually existing dollars and ten
imaginary dollars, you would choose the actually existing ones. Your preference for the actually existing
ones proves that existence adds to the perfection of a thing. Consequently, were God to lack existence,
God would be less than supremely perfect, which is contrary to what the idea
of God tells us. We must conclude,
therefore, that our idea of God is the idea of an existing thing. Existence is as inseparable from our idea
of God as having three sides is from our idea of a triangle, and is intuitive
in the same way: by clearly and distinctly perceiving what is contained in
the idea. Arguments for the
existence of God of this style did not originate with Descartes. They are commonly called “ontological”
arguments and they have had and continue to have many critics as well as many
defenders. One of the standard
objections is that existence ought not to be treated as a “perfection”
or a quality that adds to the greatness of a thing. We can describe an idea as we clearly and
distinctly perceive it to be, but it still remains a question whether
anything exists that corresponds to the idea as thus defined. When describing an idea we list the real features
or qualities that it exhibits. But existence
is not a real feature or quality.
Saying that something exists does not add to the reality of the idea
or make it a different kind of idea, as if an existing dragon were a
different species of thing from a non-existing dragon, the way a rational
animal is a different species from an irrational animal. When we say that something exists we are
merely adding the information that there is an object in the world that
corresponds to the idea; we are not listing any further real quality of the
idea itself. As Immanuel Kant was
later to put it, ten existing dollars does not contain one penny more than
ten possible dollars. If we prefer the
one to the other, it is not because the one is greater or more perfect in any
way, but only because we know that the one has a partner in the external
world as well as being a mere idea in the mind. Descartes seems to
have been sensitive to this objection even though he did not think it applies
to the case of God. But he did think
that, in other cases, it is legitimate to distinguish between the “essence”
of a thing (that collection of properties that is characteristic of a thing
and that makes it what it is), and the existence of a thing. It is only in the case of God that there is
reason to take existence to be part of the essence. In all other cases we consider existence to
be separable from essence for the very good reason that we consider it to be
possible that we might have simply made the thought up ourselves, by
imaginatively taking apart and recombining elements encountered in other
experiences to build up something entirely fanciful. But the case of God is
different because God is, so to speak, the ens realissimum or being that is the sum
total of all reality. As the infinite
being, the idea of God contains the idea of everything else that is real and
positive (imperfections of all sorts being assumed to be the result of a lack
of something rather than a positive evil).
It is the original source in which we find the component, partial
realities that we take apart and recombine to form our ideas of other things
— things that need not correspond to anything that actually exists. But in the case of God, a clear and
distinct perception on the part of the understanding compels the will to
assert that the necessity of the actual existence of an object corresponding
to the idea of the infinite being is part of what we find in the idea. A similar point might
be made in response to another common objection to the ontological argument:
that it could (absurdly) be used to prove the necessary existence of an
infinite number of things: a “perfect” island, a “perfect” rabbit, a “perfect”
white rabbit, a “perfect” white rabbit with yellow eyes, a “perfect”
three-pound white rabbit with yellow eyes, and so on. Descartes’s reply
would be that nothing that is limited or circumscribed in any way can
consistently be said to be “perfect.” The
counterexample of the supremely perfect island does not work because that
conception is self-contradictory. To
be an island is to be surrounded by water, which means being only finitely
extended. That already means being less
than supremely perfect. An island is
also just a clump of earth, lacking powers of vegetation, growth, nutrition,
reproduction, self-movement, sensation, reasoning, memory, etc. So there are a great many ways in which an
island is imperfect. That makes the
idea of a supremely perfect island maximally confused — self-contradictory. If we modify the example by adding
perfections to the idea of the island, it stops being an idea of an island
and becomes the idea of God. It is
only when we consider the idea of a being that is supremely perfect (and there can only be one such being) that we
find a reason to assert existence. In
all other cases, where the thing we conceive is thought to lack some
perfection or other. If it lacks
anything at all it is not perfect. And
if it lacks one thing then we cannot say that it must exist in order to be
perfect because it is not perfect to begin with. We would instead need to find something else
in that implies that it must exist in order to be what it is. And we can find no such thing. It is only in the case of an infinite being
that we perceive necessary existene. Principles
I.17-19. The
argument from the cause of the objective perfection of ideas. Mention of the fact that in all other cases
we distinguish existence from essence led Descartes to bring up a second
argument. This second argument is
specially designed for those whose minds are so weak that they cannot see
why, in the case of the divine being, existence is necessarily included in
the very idea of the thing. Rather
than simply appeal to what is found in the idea, this second argument appeals
to certain intuitive truths, principally the truth that nothing is not
something and that nothing cannot give rise to something. The argument proceeds
by noting that we all have an idea of God, even if some of us might wonder
whether anything actually exists corresponding to this idea. It then asks how we could have come to have
such an idea. In the background of
this argument is the notion that many of our ideas are like pictures or
images of things. It must be stressed
that this is merely a simile and is not to be taken literally. Sensations of smells, tastes, sounds, hot and
cold, and hardness and softness were all ideas for Descartes, but they are
obviously not pictures in any literal sense. All the same, like pictures,
they are of or about something. A
picture of Caesar is something — if
it is an oil painting, it consists of coloured oils smeared on canvas — but
it is also of something — an
ancient Roman general. We say,
colloquially, that Caesar is “in” the picture insofar as the picture is of Caesar,
but this is not literally true. All
that is literally in the picture is coloured oil on canvas. In the medieval tradition in which
Descartes was educated the metaphorical notion of Caesar’s being “in” the
picture was explained by saying that Caesar is “in” the picture as the object
that the painter intended the picture to represent. In other words, Caesar is in the picture,
not literally, but intentionally or objectively (that is, as an intentional
object). Descartes meant to draw our
attention to the fact that much the same thing can be said about ideas. An idea of an apple, for example, is an
idea of something that is red and cool and solid. But the idea is not itself red or cool or
solid. These qualities or “perfections”
are in the idea intentionally or objectively rather than literally. They are the objects the idea is intended
to represent, not properties of the idea itself. Descartes conveyed
this notion by remarking that over and above their “formal perfection,” as
things of a certain kind, namely ideas, our ideas picture or represent
something else, and this represented object is their “objective perfection.” Contemporary usage has made Descartes’s point less perspicacious than it was in the
17th century. Today, when we speak of
something as being “objective” we often mean to say that it has some sort of
perceiver-independent or mind-independent status. But this is not at all what Descartes had
in mind when he used the expression “objective perfection.” For Descartes, objective perfection is the
collection of real or positive qualities that are represented by an idea —
the object the idea is intended to represent.
Rather than referring to what exists outside of the mind, it refers to
what is “in” our ideas in the special, intentional sense. Whether these
“perfections” also exist in external objects outside of the idea is another
question and is certainly not something Descartes wanted to imply when he used
the phrase, “objective perfection.” Descartes proceeded to
ask what could be the cause, not just of our ideas considered just as mental
states inhering in our minds, but of the particular kinds of content the
ideas have. What could be the cause of
their objective perfections? This is a question we
still ask today. We think that some
ideas are crude and simple and that anyone could think of them. Ideas of simple things like different
shades of colour or different degrees of heat or cold are like that. But other ideas seem, because of their
complexity or beauty, to contain something grand that calls for a special
explanation. We are amazed, for
example, at how Mozart could have composed his pieces or Einstein formulated
the theory of relativity. Yet in doing these things, Mozart and Einstein were
at bottom doing nothing different than all of us do all the time: they were
simply having ideas. But because the
content of those ideas so much exceeds what the rest of us feel capable of
producing, we wonder whether they must not have had some special cause, and
we develop theories of genius or genetic endowment or cultural and
environmental circumstances to explain their occurrence. Descartes asked the
same question. He observed a rich
variety of ideas in himself: ideas of simple natures, of animals, minerals,
and vegetables, of other human beings, of angels and God — even ideas of
ideas. What accounts for the content
of these ideas? There is a certain
view of causality that lies behind this question. Descartes claimed that when a thing comes
to be, it must acquire whatever it contains from somewhere. A blade of grass, for example, must acquire
everything it contains from somewhere — from the seed it grew out of, but
also from the surrounding earth, air, water, and sunlight. The sum of things it acquires its properties
from just is the “efficient and total cause” of that thing. That efficient and total cause must either
have the properties exhibited by the effect already in it, or must contain
something greater than those properties, from which they could be extracted. As Descartes put it, “all the intricacy”
that is found in a thing “must be contained in its cause …; and it must be
contained … in actual reality, either formally or eminently” (AT VIIIA 13). Descartes proceeded to
apply this general causal principle to the specific case of ideas. He claimed that just as, in general,
everything that comes to be must have some cause that contains at least as
much as is to be found in the thing that comes to be, so every idea must have
some cause. Ideas are, after all, also
things that come to be. Moreover, this cause must not just be adequate to
account for the coming to be of the idea considered formally as an idea; it must also be adequate to account for how
the idea has come to have the content
that it does, that is, to depict or represent the object that it represents.
To do that, the cause of the idea must actually or literally contain at least
as much as is represented by the idea.
Descartes put this point by saying that the cause of the idea must formally or eminently contain at least as much as is to be found objectively in the idea. “All the intricacy [that] is contained in
the idea merely objectively — as in a picture — must be contained in its
cause …; and it must be contained not merely objectively or representatively,
but in actual reality, either formally or eminently, at least in the case of
the first and principal cause.” (AT VIIIA 13)
The cause could not just objectively
contain the qualities that the idea contains objectively, since to be
objectively in a thing means that the thing is an image or picture of
sorts. If the qualities that are
pictured by the idea are themselves only pictured by the object that causes
the idea, then that merely pushes the question back. If the cause itself is just a picture or
image, then there must be some more remote cause that it is copying, picturing,
or imaging. Ultimately, there must be
some cause that actually or literally (that is, “formally”) contains the
properties that are being represented, or that (“eminently”) contains
something even more real from which the properties being represented can in
turn be extracted. COMMENTARY We might wonder
whether Descartes was entitled to rely on the principles that everything that
comes to be must have a cause, and that a cause must contain at least as much
as is to be found in its effect. Many
of the cause-effect relations we witness regularly, such as a striking match
bursting into flame, a loud sound producing an avalanche, a shaken coke can
spraying when opened, or a flick of a switch lighting up a building, at least
appear to be cases where the effects are nothing like or contain much more
than their causes. In these cases,
something does seem to come out of nothing.
Descartes tried to answer these worries by stipulating that the “total”
cause must contain as much as the effect — for example, the cause of the
avalanche would have to be considered to be not just the sound, but the
precarious position of the snow on the mountainside — but it is not clear
that this really helps. After the doubt of Principles I.4, the total cause that I am aware of in the case of
a lighting match is just a collection of simple natures, collected together
in more complex and compound ideas.
The effect is another such collection.
Look at it as one will, the effect contains simple natures, such as
heat and bright light, that are simply not to be found anywhere in the total
set of circumstances that go to characterize the cause. This objection would
be greatly mitigated if the corpuscularian or mechanical philosophy of
Galileo, Hobbes, Boyle, and Descartes himself were correct. After all, what chiefly poses the
counterexamples to Descartes’s causal principles
are cases where sensible qualities like colour and heat suddenly emerge in
circumstances where they were previously totally absent, as in the case of
striking a match in the Antarctic night.
Such examples are answered by the mechanical philosophy, which claims
that light and colours and heat and cold are not things that actually exist
other than objectively in our ideas. There is nothing in the outside world
that resembles them, though there is something that causes them: namely
motion. And new motion is never
created out of nothing, even in the case of the creation of something like
fire (think, for example, of Hobbes’s account of fire as emerging when small
particles that were violently bouncing and vibrating in cells inside of
certain bodies suddenly manage to break free). It only ever arises as a result of
collision with previously moving parts.
So if the mechanical
philosophy were correct, then Descartes’s position
on causality would be less contrary to the evidence than it appears. Of course, the truth of the mechanical
philosophy would need to be established, and were Descartes to invoke the
truth of the mechanical philosophy to underwrite his hypothesis about the
nature of causality, he would be making an illegitimate appeal to something
that, by his own account, is uncertain. In Principles I.18 Descartes preferred to
rest his position just on the Parmenidean intuition
that something cannot come from nothing, and hence that what is more perfect
or has more reality cannot come from what is less perfect, since then the
excess reality in the effect would have had to come out of nothing. (An interesting consequence of this
intuition is that if heat and light do come out of cold and darkness, then
they simply cannot be more perfect or more real.) But there is a more
radical question we might ask: Why
should we suppose that whatever comes into being has to be caused by
something? Why could things not simply
pop into existence? To reply that this
would be impossible because then the effect would have been produced by some
dark, featureless entity we call “nothing,” and such an entity cannot act or
do anything, nor can it contain anything that it could contribute to an
effect, is to beg the question. The
question is: “Why does an effect need
to be produced by anything else at all (including a thing called
“nothing”)? Why could it not simply
pop into existence?” To answer this
question by saying “because then it would not be produced by anything (i.e.,
it would be produced by “nothing”) is not to give an answer at all, but
simply to repeat the very thing that needs to be proven. This is a good example
of a troubling issue alluded to earlier: the difficulty of distinguishing
between clear and distinct perceptions, on the one hand, and juvenile
preconceptions on the other. Descartes would have maintained that the
principle that a cause must contain at least as much as is to be found in its
effect is clearly and distinctly perceived.
But is it, or is it merely a juvenile preconception? Descartes’s causal
principle gives voice to what was in his day a traditional and blindly
accepted view of the nature of causality.
We might call this view the containment model. According to it a cause is not simply a
signal event that often or necessarily happens before an effect occurs; it is
something that actively produces its effect.
It produces the effect, moreover, by either drawing together some of
its own content and excreting this content as its effect, much as a woman
gives birth to a child; or by drawing together and reforming surrounding
content, as a builder does with bricks, wood, and mortar; or by impressing or
imposing or infecting the raw material that already exists in the effect with
its content, much as a signet ring impresses its form on the sealing wax, a
fire imposes its heat on the surrounding stones, or a diseased person infects
others with their disease. This is not
the only way to understand causality, as will be seen later in connection
with Hume. Ironically, Descartes’s own allusions to “eminent” containment
challenge this supposedly certain principle and so poses further problems for
his argument. Remark
on eminent causality. Descartes’s causal
principle has an untoward implication.
God is supposed to have created the world. But the world is composed of extended
bodies. If the cause of an effect is
supposed to contain at least much reality as is found in the effect, then it
would appear to follow that God must also be extended. But extension is not one of the attributes
traditionally ascribed to the Christian God, who is rather supposed to be
purely spiritual. Descartes was not the
only Christian philosopher who had to confront this theological
difficulty. Any Christian philosopher
who shared Descartes’s views on causality — and
that included virtually all the philosophers of the medieval period — had the
same problem. The containment model of
causality appears to contradict Christian theology. According to the
containment model, if God created extended bodies, God must contain
extension. According to Christian
theology, God cannot be extended. Rather than reject the
one or the other of these doctrines, Descartes and his medieval predecessors
tried to have things both ways by claiming that, though God does not contain
extension, he does contain things that are more perfect than extension. Extension was supposed to flow from these
more perfect qualities without contradicting the principle that the cause
must contain at least as much as is to be found in its effect. But it is not
clear that this notion can be invoked without giving up the containment model
of causality. If a supposedly more
eminent or perfect or real being can produce something it does not itself
contain, then, however mean or ignoble that result may be when compared to
what is actually present in the more eminent or perfect or real being, it is
still something that is not present in the more eminent or perfect or real
being. It must therefore have come to
be out of nothing, in violation of the containment model. In the final analysis, the notion of eminent
causality is nothing more than what Bacon would have called an Idol of the Theatre:
a piece of jargon used to paper over the existence of a fundamental
theoretical inconsistency. Principles
I.17-19. The
argument from the cause of the objective perfection of ideas, cont.’d. Setting
these worries aside for the moment, let’s return to Descartes’s
second argument from the existence of God.
We all possess an idea of God, that is of an
infinitely perfect being. Some of us
may think that while we may have such an idea, it does not follow that any
object actually exists corresponding to it.
But, armed with the notion that the cause of an idea must actually
contain at least as much as is found in the object of that idea, Descartes
asked how we could have come by such an idea.
The cause of the idea of a dragon may not be a dragon, but it has to
have all the perfections in it that we find rearranged in our idea of a
dragon: shape, size, colour, motion, and so on. Otherwise, there would be something in the
effect that is greater than the cause and this greater reality would have to
have come out of nothing which, so Descartes maintained, is clearly
impossible. This is something that
people commonly accept, and we see instances of this reasoning around us all
the time, from parents who demand to know who gave their children the ideas
they have of sex to historians of philosophy who ask what gave a particular
philosopher this or that novel idea.
In the 1990’s when the Eastern Block states collapsed, they did so
more or less from West to East and a popular theory at the time was that this
was due to the fact that television signals from Western countries were being
received in East Germany and Poland, giving those people an idea of Western
lifestyles that those in the Soviet Union did not have and could not produce
on their own, and so making the Germans and Poles less willing to put up with
the state of affairs in their countries than the Soviets. At this point,
Descartes was in a position to claim that the idea of God could have nothing
less than God as its cause. He could
not have produced this idea himself, he claimed, because, as he was painfully
aware, he was not himself supremely perfect, but possessed only limited
understanding and a liability to make mistaken judgments. Given that he was this way, he ought to
have been incapable of forming the idea of any more perfect being. Yet he could. The idea must therefore have some other
cause than himself.
But nothing that falls short of infinite perfection could be the cause
of his idea of an infinitely perfect being, either. Only a supremely perfect being could have
given him the idea of a supremely perfect being. Such a being must therefore exist. Principles
I.20-23. The
argument to the cause of the thing that has the ideas. This argument has not convinced very many
people. Descartes thought that one
reason for this might be that we cannot recall a time at which we first
received for formed the idea of God.
This might lead some to suppose that the idea does not need any sort
of special cause. Perhaps it is simply
“natural.” Accordingly, over Principles I.20 Descartes complemented
his argument by appeal to the cause of our idea with an argument that appeals
to the cause of ourselves and of everything we have always found within
ourselves. Granting that we are
certain not merely that our ideas (among them perhaps an idea of God) exist,
but also that we ourselves exist, we can also inquire into the cause of
ourselves. In giving the argument, Descartes
made a third appeal to principles discerned in the light of nature to claim
that a being that finds within itself an idea of something more perfect than
itself could not have been its own cause.
For, if it were, it would naturally have given itself whatever extra perfections
it finds in this idea. Were I powerful
enough to bring myself into existence, I ought to have been powerful enough
to give myself some more of the perfections that I think of when I think of
an all perfect being. If I could bring
myself into existence out of nothing, I ought surely to be able to do
something as easy by comparison as give myself some more perfect knowing
powers, so that I would not be infected with the doubts that I find within
myself or recall the history of past mistakes that I do. But that is
something I manifestly have not managed bring about. Thus, some more perfect than we are must
have created not only our idea of it, but ourselves as well. Principles I.21.
The doctrine of constant creation.
At Principles I.21,
Descartes claimed that this causal argument can be made all the more
compelling by considering the nature of time.
In the third of his Meditations
on First Philosophy he had written, “it is obvious to anyone who pays
close attention to the nature of time, that plainly the same force and action
are needed to preserve anything at each individual moment that it lasts as
would be required to create that same thing anew . . . conservation differs
from creation solely by virtue of a distinction of reason” (AT VII 49). Principles
I.21 echoes this doctrine: “the nature of time is such that its parts are not
mutually dependent, and never coexist.
Thus, from the fact that we now exist, it does not follow that we
shall exist a moment from now.” When time passes, what
exists now, the present, becomes past. But the past no longer exists. To say that the present becomes past is to
say that it gets destroyed. But if
what exists now gets destroyed in the very next instant by the passage of
time, how is it that we still see it continuing from one moment to the
next? Obviously, what got destroyed
must have been recreated. And since
the passage of time destroys everything that exists from moment to moment,
everything must be constantly recreated from moment to moment. This is why conservation does not really
differ from creation, and why the same force and power is required to
preserve a thing in existence as to create it in the first place — preserving
it just means constantly recreating it from one moment to the next. This is called the
doctrine of constant creation.
According to it, the world was not just created in the beginning, but
must be continually recreated from moment to moment. Were it not to recreated, it would blink
out of existence. The doctrine of
constant creation will be important for a proper understanding of Cartesian
physics, and in the hands of Pierre Bayle, it was exploited to buttress a
more profound sceptical argument than any Descartes ever envisioned. In this context,
Descartes appealed to the doctrine to make the point that we could not
possibly be the causes of our own, continued self-existence. For if we were, we would have a power, the
power to bring something to be out of nothing, that
is so vast that surely we ought to have been able to employ it to make
ourselves more perfect than we currently are.
The conclusions are twofold:
First, we must have some cause other than ourselves that preserves us
in existence from moment to moment.
Second, this cause must also be preserving itself and the whole
universe in existence from moment to moment.
And insofar as it is able to do so, it must be employing that power to
make itself supremely perfect, since such power must have no bounds and it
would certainly want to do so. There are still
problems, however. One is posed by
Descartes own claim that whatever ideas we find within ourselves must be
considered as qualities or attributes of ourselves (Principles I.11) combined with his admission that it is not
in the nature of a finite being to fully comprehend the infinite (Principles I.19). This would suggest that we simply do not
have any sort of adequate idea of an infinitely perfect being. The best we can manage is to think of
things that we ourselves possess or conceive, all of which fall far short of
what would be contained in an infinitely perfect being, and none of which
require appeal to an infinitely perfect cause if their existence is to be
accounted for. This does not get
around the argument from constant creation, which asks how we could continue
in existence from moment to moment, and why, if we are the ones responsible
for this prodigious feat, we would not do something so much simpler by
comparison as create ourselves with enhanced cognitive powers. But the argument from constant creation
poses its own problems. It
countenances a counterexample to the supposedly intuitively evident principle
that something cannot come from nothing.
According to the doctrine of constant creation, this is so far from
being the case that everything is constantly coming from nothing, being a
product of God’s continued recreation of the universe out of nothing from
moment to moment — necessarily out of nothing since what exists at any moment
is annihilated at the next. Granted,
it is only a supremely powerful being who is being allowed to have this
extraordinary power. But the fact
remains: bringing something out of nothing is doable. So we cannot suppose that it is simply
impossible that something should come out of nothing. That having been said,
the view that causes must be like their effects and must transmit something
of what they contain to their effects was central to the mechanical
philosophy, which maintained that motion in bodies is caused by collision
with other moving bodies and that the cause loses as much of its motion as it
communicates to the effect. This would
have made the causal principle at the root of his argument a natural
preconception for Descartes to uncritically accept. Ironically, the method of doubt was
supposed to root out such infantile prejudices. ESSAY QUESTIONS AND
RESEARCH PROJECTS
1. Was
Descartes entitled to claim that there is no way to distinguish waking from
dreaming?
2. Could a
deceiver who systematically deceives me, and ensures that I never come across
any evidence of my mistake, really be a deceiver?
3. Was
Descartes entitled to claim, at this stage in his argument, that he did not
need to have a body in order to be able to understand, affirm, deny, doubt,
will, etc.?
4. Could an
evil genius make me be mistaken about my intuitions?
5. Descartes
claimed to know that he is a thinking thing.
However, to say that what exists is a “thing” suggests that there is
something that bears properties (in this case, that there is something that
has thoughts) and that this thing endures over time, perhaps altering in
state (i.e., changing its thoughts) over time. Is there anything in Descartes’s
account that might entitle him to affirm that, in addition to the thoughts
that he knew must exist, there must be some one substance in which they all
inhere?
6. Assess the
adequacy of Descartes’s attempt to defend his
ontological argument for the existence of God against the objections he
himself raises to that argument.
Consider whether there are any other, more serious objections he fails
to consider and then consider whether he could also answer those objections.
philosophy of his
own. The chief point in dispute
between Malebranche and Arnauld was whether ideas
are objects of apprehension (the view of Malebranche), or acts whereby
objects are apprehended (the view of Arnauld). The Malebranche/Arnauld
dispute has been the subject of extensive scholarly study, but two early
papers on the topic are classics that should be read by any student of 17th
century philosophy: Robert McRae, “‘Idea’ as a Philosophical Term in the 17th
Century,” Journal of the history of
ideas 26 (1965): 175-184, and John Yolton,
“Ideas and Knowledge in Seventeenth-Century Philosophy,” Journal of the history of philosophy 13 (1975): 145-166. Study
these two papers and report on the main results of each.
8. Does
Descartes have a principled way of distinguishing between what is known by
the “light of nature” and what is known by “natural impulse”?
9. Consider
whether Descartes is in any position to claim to be certain of any of the
causal principles he invokes in Principles
I.18. Try to come up with the best
argument you can to defend his position and the best argument you can to
reject it. Determine which argument is
the strongest. 10.
Descartes’s notion of
eminent causality is drawn from medieval philosophy. Undertake a research project to discover
just how this notion was understood by medieval philosophers. (Note that rather than speak of eminent
causality, the medievals might have instead
discussed eminent containment of a form, which they would have contrasted
with literal exhibition of a form.)
Determine whether the medievals managed to
articulate a clear, coherent sense in which it is possible for a thing to
contain a form it does not literally exhibit.
Then determine whether Descartes had any right to employ this notion
(note that, despite the doubts of Meditations
I, he only needed to make a case that it is possible that there might be
eminent causes). If he dids have a right to employ the notion, did he also have
a right to make the further claim that he could be the “eminent” cause of his
idea of extension? |
