Meditations on First Philosophy in which are demonstrated the

Meditations on First Philosophy

in which are demonstrated the existence of God and the distinction between

the human soul and body

René Descartes

[Brackets]

enclose editorial explanations. Small

dots

enclose material that has been added, but can be read as

though it were part of the original text. Occasional

•

bullets, and also indenting of passages that are not quotations,

are meant as aids to grasping the structure of a sentence or a thought. Every four-point ellipsis . . . . indicates

the omission of a brief passage that seems to present more difﬁculty than it is worth.—In his title for this work,

Descartes is following a tradition (started by Aristotle) which uses ‘ﬁrst philosophy’ as a label for metaphysics.

First launched: July 2004 Last amended: April 2007

Contents

First Meditation 1

Second Meditation 3

Third Meditation 9

Fourth Meditation 17

Fifth Meditation 23

Sixth Meditation 27

Meditations René Descartes Fifth Meditation

Fifth Meditation:

The essence of material things, and the existence of God considered a second time

There are many enquiries still to be made about God’s

attributes, and many about my own nature (that is, the

nature of my mind). I may take these up at some time; but

right now I have a more pressing task. Now that I have seen

how to reach the truth—what to do and what to avoid—I

must try to escape from the doubts that beset me a few days

ago, and see whether anything can be known for certain

about material objects.

Before enquiring into whether there are any such things,

I should consider the

ideas

of them in my thought, in order

to see which of those ideas are distinct and which confused.

I distinctly imagine

quantity

—that is, the length, breadth

and depth of the quantity, or rather of the thing that is

quantiﬁed. I also enumerate the thing’s parts, to which I

attribute various sizes, shapes, positions and movements;

and to the movements I attribute various durations,

that is,

I say how long each movement lasts·.

Size, shape, position and so on are well known and

transparent to me as

general kinds

of phenomenon, but

there are also countless

particular

facts involving them that

I perceive when I attend to them. The truths about all these

matters are so open to me, and so much in harmony with

my nature, that when I ﬁrst discover any of them it feels

less like

•

learning something new than like

•

remembering

something I had known before, or

•

noticing for the ﬁrst time

something that was already in my mind without my having

turned my mental gaze onto it.

The most important point is that I ﬁnd in myself countless

ideas of things that can’t be called

nothing

, even if they don’t

exist anywhere outside me. For although I am free to think

of these ideas or not, as I choose,

I didn’t invent them

: they

have their own true and immutable natures,

which are not

under my control

. Even if there are not and never were

any triangles outside my thought, still, when I imagine a

triangle

I am constrained in how I do this, because

there is

a determinate nature or essence or form of

triangle

that is

eternal, unchanging, and independent of my mind. Consider

the things that I can prove about the triangle—that its three

angles equal two right angles, that its longest side is opposite

its greatest angle, and so on. I now clearly recognize these

properties of the triangle, whether I want to or not, even if I

didn’t give them a thought when the triangle ﬁrst came into

my mind. So they can’t have been invented by me.

It does not help to point out that I have sometimes seen

triangular bodies, so that the idea of the triangle might have

come to me from them through my sense organs. I can

prove truths about the properties not only of triangles but of

countless other shapes that I know I have never encountered

through the senses. These properties must be

something

not pure nothing: whatever is true is something; and these

properties are true because I am clearly aware of them. (I

have already proved that everything of which I am clearly

aware is true; and even if I hadn’t proved it, my mind is so

constituted that I

have to

assent to these

geometrical

propo-

sitions as long as I perceive them.) I remember, too, that even

back in the times when the objects of the senses held my

attention, I regarded the clearly apprehended propositions of

pure mathematics—including arithmetic and geometry—as

the most certain of all.

Meditations René Descartes Fifth Meditation

The preceding two paragraphs lead to this conclusion

The mere fact that I ﬁnd in my thought an idea of something

x, and vividly and clearly perceive x to have a certain pr operty,

it follows that x really does have that property. Can I not turn

this to account in a second argument to prove the existence

of God? The idea of God (that is, of a supremely perfect

being) is certainly one that I ﬁnd within me, just as I ﬁnd the

ideas of shapes and numbers; and I understand

from this

idea

that it belongs to God’s nature that

he always exists

This understanding is just as vivid and clear as what is

involved in

mathematical

proofs of the properties of shapes

and numbers. So even if I have sometimes gone wrong in

my meditations in these past days, I ought still to regard the

existence of God as being at least as certain as I have taken

the truths of mathematics to be.

At ﬁrst sight, this looks like a trick. Where things other

than God are involved, I have been accustomed to distinguish

a thing’s existence from its essence.

The question ‘What

is the

essence

of triangles (or ﬂames or sparrows)?’ asks

what it takes for something to qualify as a triangle (or ﬂame

or sparrow). Answering this still leaves open the

existence

question, which asks whether there are any triangles (or

ﬂames or sparrows)

. I can easily believe that in the case of

God, also, existence can be separated from essence,

letting

us answer the

•

essence question about God while leaving the

•

existence question open

, so that God can be thought of as

not existing. But on more careful reﬂection it becomes quite

evident that, just as having-internal-angles-equal-to-180

can’t be separated fr om the idea

or essence

of a triangle,

and as the idea of highlands can’t be separated from the

idea of lowlands, so existence can’t be separated from the

essence of God. Just as it is self-contradictory to think of

highlands in a world where there are no lowlands

, so it is

self-contradictory to think of

God as not existing

—that is, to

think of a supremely perfect being as lacking a perfection,

namely the perfection of existence.

[What Descartes wrote is

usually translated as ‘mountains in a world where there are no valleys’,

but that is obviously not self-contradictory. The Latin provides no escape

from this, but Descartes may have been thinking in French, in which

vallée can mean ‘valley’ in our sense but can be used to refer to foothills,

the lower slopes of a mountain, or the plain immediately surrounding the

mountain. So ‘highlands’/‘lowlands’ has been adopted as a compromise:

compact and fairly close to what he presumably meant.]

Here is a possible objection to the preceding two para-

graphs·:

I can’t think of God except as existing, just as I can’t

think of a river without banks. From the latter fact,

though, it certainly doesn’t follow that there are any

rivers in the world; so why should it follow from the

former fact that God exists? How things are in reality

is not settled by my thought; and just as I can imagine

a winged horse even though no horse has wings, so I

can attach existence to God in my thought even if no

God exists.

This involves false reasoning. From the fact that I can’t think

of a river without banks, it does not follow that a river with

banks exists anywhere, but simply that

river

and

banks

—

whether or not there are any in reality—are inseparable. On

the other hand, from the fact that I can’t think of God except

as existing it follows that

God

and

existence

are inseparable,

which is to say that God r eally exists. My thought doesn’t

make it so; it doesn’t create necessities. The inﬂuence runs

the opposite way: the necessity of the thing constrains how

I can think, depriving me of the freedom to think of God

without existence (that is, a supremely perfect being without

a supreme perfection), like my freedom to imagine a horse

with or without wings.

Meditations René Descartes Fifth Meditation

Here is a

further

possible objection to this line of

thought:

Admittedly, once I have supposed that

•

all perfections

belong to God, I must suppose that he exists, because

existence is one of the perfections. But what entitles

me to suppose God to have all perfections? Similarly,

if I suppose that

•

all quadrilaterals can be inscribed

in a circle, I have to conclude that a rhombus can be

inscribed in a circle; but that is plainly false, which

shows that the original supposition was wrong.

I agree that I don’t have to think about God at all; but

whenever I do choose to think of him, bringing the idea of

the ﬁrst and supreme being

out of my mind’s store, I

must

attribute all perfections to him, even if I don’t attend to them

individually straight away. This necessity

in my thought

guarantees that, when I later realize that existence is a

perfection, I am right to conclude then that the ﬁrst and

supreme being exists. Similarly, I don’t ever have to imagine

a triangle; but whenever I do wish to consider a ﬁgure with

straight sides and thr ee angles, I

must

attribute to it proper-

ties from which it follows that its three angles equal no more

than 180

, even if I don’t notice this at the time. When on

the other hand I examine what ﬁgures can be inscribed in a

circle, I am not compelled to think that this class includes all

quadrilaterals. Indeed, I cannot—while thinking vividly and

clearly—even

pretend

that all quadrilaterals can be inscribed

in a circle. This kind of false pretence is vastly different from

the true ideas that are innate in me, of which the ﬁrst and

chief is the idea of God. This idea isn’t a ﬁction, a creature of

my thought, but rather an image of a true and unchanging

nature; and I have several indications that this is so.

•

God

is the only thing I can think of whose existence necessarily

belongs to its essence.

•

I can’t make sense of there being

two or more Gods of this kind; and after supposing that

one God exists, I plainly see that it is necessary that he has

existed from eternity and will stay in existence for eternity.

•

I perceive many other attributes of God, none of which I can

remove or alter.

Whatever method of proof I use, though, I am always

brought back to the fact that nothing completely convinces

me except what I vividly and clearly perceive. Some things

that I vividly and clearly perceive ar e obvious to everyone;

others can be learned only through more careful investiga-

tion, but once they are discovered they are judged to be just

as certain as the obvious ones. (Compare these two truths

about right-angled triangles: ‘The square on the hypotenuse

equals the sum of the squares on the other two sides’ and

‘The hypotenuse is opposite the largest angle’. The former

is less obvious than the latter; but once one has seen it,

one believes it just as strongly.)

Truths about God are not

in the immediately obvious class, but they

ought

to be

. If

I were not swamped by preconceived opinions, and if my

thoughts were not hemmed in and pushed around by images

of things perceived by the senses, I would acknowledge God

sooner and more easily than anything else. The supreme

being exists; God, the only being whose essence includes

existence, exists; what is more self-evident than that?

Although I came to see this only through careful thought,

I am now just as certain of it as I am of anything at all. Not

only that, but I see that all other certainties depend on this

one, so that without it I can’t know anything for sure.

The

next two paragraphs explain why this is so·.

While I am perceiving something vividly and clearly, I

can’t help believing it to be true. That is a fact about my

nature. Here is another: I can’t ﬁx my mind’s eye continually

on the same thing, so as to keep perceiving it clearly; so that

sometimes the arguments that led me to a certain conclusion

slip out of my focus of attention, though I remember the

Meditations René Descartes Fifth Meditation

conclusion itself. That threatens me with the following state

of affairs, from which I am protected only by being awar e of

the existence of God:

In a case where I am not attending to the arguments

that led me to a conclusion, my conﬁdence in the

conclusion might be undermined by arguments going

the other way. When I think hard about triangles, for

instance, it seems quite obvious to me—steeped as

I am in the principles of geometry—that a triangle’s

three angles are equal to 180

; and while I am attend-

ing to the proof of this I can’t help believing it. But

as soon as I turn my mind’s eye away from the proof,

then in spite of still remembering

that

I perceived it

very clearly

but without now getting it clear in my

mind again

, I can easily doubt its truth. So nothing

is ever ﬁnally established and settled—I can have no

true and certain knowledge, but only shifting and

changeable opinions. For I can convince myself that I

am naturally liable to go wrong sometimes in matters

that I think I perceive as evidently as can be. This

seems even more likely when I remember that I have

often regarded as certainly true some propositions

that other arguments have later led me to think false.

That is what my situation would be if I were not aware of the

existence of God.

But now I have seen that God exists, and have understood

that everything else depends on him and that he is not a

deceiver; from which I have inferred that

everything that I

vividly and clearly perceive must be true

. So even when I

am no longer attending to the arguments that led me to

accept this (

i.e. the proposition about triangles

), as long

as I remember that I vividly and clearly perceived it no

counter-arguments can make me doubt it. It is something

that I know for certain

and in an unshakable way

to be true.

That applies not only to this one proposition but to anything

that I remember ever having proved in geometry and the like.

Why should I call these matters into doubt?

•

Because I am

so built as to be prone to frequent error? No: I now know

that when I have something in mind in a transparently clear

way I cannot be in error about it.

•

Because I have in the

past regarded as certainly true many things that I afterwards

recognized to be false? No: the things that I later came to

doubt had not been vividly and clearly perceived in the ﬁrst

place: I had come to accept them for reasons that I later

found to be unreliable, because I hadn’t yet discover ed this

rule for establishing the truth.

•

Because I may be dreaming,

so that my present thoughts have as little truth as those

of a person who is asleep? I put this objection to myself a

while ago. It doesn’t change anything, because if something

is evident to my intellect, even when I am dreaming, then it

is true.

Thus I see plainly that the certainty and truth of all

knowledge depends strictly on my awareness of the true

God. So much so that until I became aware of him I

couldn’t perfectly know anything. Now I can achieve full

and certain knowledge of countless matters, both concerning

God himself and other things whose natur e is intellectual,

and also concerning the whole of the corpor eal nature that

is the subject-matter of pure mathematics.