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René
Descartes
Discourse
on Method
for Reasoning Well and for Seeking Truth in the Sciences
1637
[For
the French text of Descartes' Discourse click here]
[For a short introduction to Descartes' Discourse click here]
Translator’s
Note
This
translation, prepared by Ian Johnston of Malaspina University-College, Nanaimo,
BC, Canada, is in the public domain and may be used by anyone, in whole or in
part, for any purpose, without permission and without charge, provided the
source is acknowledged.
In
the following text most of the paragraphs in Descartes' original text have been
broken down into smaller units. The asterisk (*) in the text indicates a
link to an explanatory endnote provided by the translator.
For
comments, questions, suggestions for improvements, please contact Ian Johnston
at Malaspina University-College, 900 Fifth Street, Nanaimo, BC, Canada, or at johnstoi@mala.bc.ca.
If you would like this text in the form of a Publisher file, so that you can print it off as a small booklet, please consult the following: Publisher Files.
Printed versions of this text suitable for classroom use are available from Prideaux Street Productions.
Historical
Note
Rene
Descartes (1596-1650) published Discourse on Method in 1637.
The original work contained sections
on optics, geometry, and meteorology. The
fourth section, the Discourse, outlined the basis for a new method of
investigating knowledge. He later
(in 1641) published a more detailed exploration of the philosophical basis for
this new approach to knowledge in Meditations on First Philosophy.
Descartes
Discourse on Method
If
this discourse seems too long to be read in a single sitting, it can be divided
up into six parts. In the first will be found various considerations concerning
the sciences; in the second, the principal rules of the method which the author
has discovered; in the third, some rules of morality which he has derived by
this method; in the fourth, the reasons which enable him to establish the
existence of God and of the human soul, which are the foundations of his
metaphysics; in the fifth part, the order of questions in physics which he has
looked into, and particularly the explanation for the movements of the heart and
for some other difficulties which are part of medicine, including the difference
which exists between our souls and those of animals; in the last part, some
matters he believes necessary for further research into nature, beyond where he
has been, along with some reasons which have induced him to write.
Part
One
The
most widely shared thing in the world is good sense, for everyone thinks he is
so well provided with it that even those who are the most difficult to satisfy
in everything else do not usually desire to have more good sense than they have.
In this matter it is not likely that everyone is wrong.
But this is rather a testimony to the fact that the power of judging well
and distinguishing what is true from what is false, which is really what we call
good sense or reason, is naturally equal in all men, and thus the diversity of
our opinions does not arise because some people are more reasonable than others,
but only because we conduct our thoughts by different routes and do not consider
the same things. For it is not enough to have a good mind. The main thing is to
apply it well. The greatest minds are capable of the greatest vices as well as
the greatest virtues, and those who proceed only very slowly, if they always
stay on the right road, are capable of advancing a great deal further than those
who rush along and wander away from it.
As
for myself, I have never presumed that my mind was anything more perfect than
the ordinary mind. I have often even wished that I could have thoughts as quick,
an imagination as clear and distinct, or a memory as ample and actively involved
as some other people. And I know of no qualities other than these which serve to
perfect the mind. As far as reason, or sense, is concerned, given that it is the
only thing which makes us human and distinguishes us from animals, I like to
believe that it is entirely complete in each person, following in this the
common opinion of philosophers, who say that differences of more and less should
occur only between accidental characteristics and not at all between the forms
or essential natures of individuals of the same species.
But
I am not afraid to state that since my youth I think I have been very fortunate
to find myself on certain roads which have led me to considerations and maxims
out of which I have created a method by which, it seems to me, I have a way of
gradually increasing my knowledge, raising it little by little to the highest
point which the mediocrity of my mind and the short length of my life can allow
it to attain. For I have already harvested such fruit from this method that,
even though, in judging myself, I always try to lean towards the side of
distrust rather than to that of presumption and although, when I look with a
philosopher's eye on the various actions and enterprises of all men, there are
hardly any which do not seem to me vain and useless, I cannot help deriving
extreme satisfaction from the progress which I think I have already made in my
research into the truth and in conceiving such hopes for the future that, if
among the occupations of men, simply as men, there is one which is surely good
and important, I venture to think it's the one I have chosen.
However,
it could be the case that I am wrong and that perhaps what I have taken for gold
and diamonds is only a little copper and glass. I know how much we are subject
to making mistakes in what touches ourselves and also how much we should beware
of the judgments of our friends when they favour us. But I will be only too
happy to make known in this discourse what roads I have followed and to reveal
my life, as if in a picture, so that each person can judge it. Learning from
common talk the opinions people have of this discourse may be a new way of
teaching me, something I will add to those which I habitually use.
Thus,
my design here is not to teach the method which everyone should follow in order
to reason well, but only to reveal the ways in which I have tried to conduct my
own reasoning. Those who take it upon themselves to give precepts must consider
themselves more skilful than those to whom they give them, and if they are
missing something, then they are culpable. But since I intend this text only as
a history, or, if you prefer, a fable, in which, among some examples which you
can imitate, you will, in addition, perhaps find several others which you will
have reason not to follow, I hope that it will be useful to some people, without
harming anyone, and that everyone will find my frankness agreeable.
I
was nourished on literature from the time of my childhood. Because people
persuaded me that through literature one could acquire a clear and assured
understanding of everything useful in life, I had an intense desire to take it
up. But soon after I had completed that entire course of study at the end of
which one was usually accepted into the rank of scholars, I changed my opinion
completely. For I found myself embarrassed by so many doubts and errors that it
seemed to me I had gained nothing by trying to instruct myself, other than the
fact that I had increasingly discovered my own ignorance.
Yet
I had been in one of the most famous schools in Europe, a place where I thought
there must be erudite men, if there were such people anywhere on earth. I had
learned everything which the others had learned, but still, not being happy with
the sciences which we had been taught, I had gone through all the books which I
could lay my hands on dealing with those sciences which are considered the most
curious and rare. In addition, I knew how other people were judging me, and I
saw that they did not consider me inferior to my fellow students, although among
them there were already some destined to fill the places of our teachers. And
finally our age seemed to me as flourishing and as fertile in good minds as any
preceding age. Hence, I took the liberty of judging all the others by myself and
of thinking that there was no doctrine in the world of the kind I had previously
been led to hope for.
However,
I did not cease valuing the exercises which kept people busy in the schools. I
knew that the languages one learns there are necessary for an understanding of
ancient books, that the gracefulness of fables awakens the intellect, that the
memorable actions of history raise the mind, and if one reads with discretion,
help to form one's judgment, that reading all the good books is like a
conversation with the most honest people of past centuries, who were their
authors, even a carefully prepared dialogue in which they reveal to us only the
best of their thoughts, that eloquence has incomparable power and beauty, that
poetry has a most ravishing delicacy and softness, that mathematics has very
skilful inventions which can go a long way toward satisfying the curious as well
as facilitating all the arts and lessening the work of men, that the writings
which deal with morals contain several lessons and a number of exhortations to
virtue which are extremely useful, that theology teaches one how to reach
heaven, that philosophy provides a way of speaking plausibly on all matters and
makes one admired of those who are less scholarly, that jurisprudence, medicine,
and the other sciences bring honour and riches to those who cultivate them, and
finally that it is good to have examined all of them, even the most
superstitious and false, in order to know their legitimate value and to guard
against being wrong.
But
I believed I had already given enough time to languages and even to reading
ancient books as well, and to their histories and stories. For talking with
those from other ages is the same as traveling. It is good to know something
about the customs of various people, so that we can judge our own more sensibly
and do not think everything different from our own ways ridiculous and
irrational, as those who have seen nothing are accustomed to do. But when one
spends too much time traveling, one finally becomes a stranger in one's own
country, and when one is too curious about things which went on in past ages,
one usually lives in considerable ignorance about what goes on in this one. In
addition, fables make us imagine several totally impossible events as possible,
and the most faithful histories, even if they neither change nor increase the
importance of things to make them more worth reading, at the very least almost
always omit the most menial and less admirable circumstances, with the result
that what's left in does not depict the truth. Hence, those who regulate their
habits by the examples which they derive from these histories are prone to fall
into the extravagances of the knights of our romances and to dream up projects
which surpass their powers.
I
placed a great value on eloquence, and I was in love with poetry, but I thought
that both of them were gifts given to the mind rather than fruits of study.
Those who have the most powerful reasoning and who direct their thoughts best in
order to make them clear and intelligible can always convince us best of what
they are proposing, even if they speak only the language of Lower Brittany and
have never learned rhetoric. And those who possess the most pleasant rhetorical
inventions and who know how to express them with the most adornment and
smoothness cannot help being the best poets, even though the art of poetry is
unknown to them.
I
found mathematics especially delightful because of the certainty and clarity of
its reasoning. But I did not yet notice its true use. Thinking that it was
practical only in the mechanical arts, I was astonished that on its foundations,
so strong and solid, nothing more imposing had been built up. By contrast, I
compared the writings of the ancient pagans which deal with morality to really
superb and magnificent palaces built of nothing but sand on mud. They raise the
virtues to a very great height and make them appear valuable, above everything
in the world, but they do not teach us to know them well enough, and often what
they teach with such a beautiful name is only insensibility or pride or despair
or parricide.
I
revered our theology and aspired as much as anyone to reach heaven, but having
learned, as something very certain, that the road there is no less open to the
most ignorant as to the most learned and that the revealed truths which lead
there are beyond our intelligence, I did not dare to submit them to the frailty
of my reasoning, and I thought that undertaking to examine them successfully
would require me to have some extraordinary heavenly assistance and to be more
than a man.
I
will say nothing of philosophy other than this: once I saw that it had been
cultivated for several centuries by the most excellent minds which had ever
lived, and that, nonetheless, there was still nothing in it which was not
disputed and which was thus not still in doubt, I did not have sufficient
presumption to hope to fare better there than the others. Considering how many
different opinions, maintained by learned people, philosophy could have about
the same matter, without there ever being more than one which could be true, I
reckoned as virtually false all those which were merely probable.
Then, as for the other sciences, since they borrow their principles from
philosophy, I judged that nothing solid could have been built on such
insubstantial foundations; and neither the honour nor the profit which they
promise were sufficient to convince me to learn them; for, thank God, I did not
feel myself in a condition which obliged me to make a profession of science in
order improve my fortune, and, although I did not, in some cynical way,
undertake to proclaim my disdain for glory, nonetheless I placed very little
value on the glory I could hope to acquire only through false titles. And
finally, as for bad doctrines, I thought I already understood sufficiently what
they were worth in order not be taken in either by the promises of an alchemist,
by the predictions of an astrologer, by the impostures of a magician, or by the
artifice or the bragging of any of those who made a profession of knowing more
than they know.
That's
why, as soon as my age permitted me to leave the supervision of my professors, I
completely stopped the study of letters, and, resolving not to look any more in
any other science except one which could be found inside myself or in the great
book of the world, I spent the rest of my youth traveling, looking into courts
and armies, associating with people of various humours and conditions,
collecting various experiences, testing myself in the encounters which fortune
offered me, and everywhere reflecting on the things I came across from which I
could to draw some profit.
For
it seemed to me that I could arrive at considerably more truth in the reasoning
that each man makes concerning the matters which are important to him and in
which events could punish him soon afterwards if he judged badly, than in the
reasoning made by a man of letters in his study concerning speculations which
produce no effect and which are of no consequence to him, except perhaps that
from them he can augment his vanity—and all the more so, the further his
speculations are from common sense, because he would have had to use that much
more wit and artifice in the attempt to make them probable. And I always had an
extreme desire to learn to distinguish the true from the false, to see clearly
in my actions, and to proceed with confidence in this life.
It's
true that while I did nothing but examine the customs of other men, I found
hardly anything there to reassure me, and I noticed as much diversity among men
as I had earlier among the opinions of philosophers. Consequently, the greatest
profit which I derived from this was that, by seeing several things which,
although they seem really extravagant and ridiculous to us, were commonly
accepted and approved by other great people, I learned not to believe too firmly
in anything which I had been persuaded to believe merely by example and by
custom. Thus, I gradually freed myself of plenty of errors which can obfuscate
our natural light and make us less capable of listening to reason. But after I
had spent a few years studying in this way in the book of the world, attempting
to acquire some experience, one day I resolved to study myself as well and to
use all the powers of my mind to select ways which I should follow, a task which
brought me considerably more success, it seems to me, than if I had never gone
away from my own country and my books.
Part
Two
I
was then in Germany, summoned there by the wars which have not yet concluded. As
I was returning to the army from the coronation of the emperor, the onset of
winter stopped me in quarters where, not finding any conversation to divert me
and, by good fortune, not having any cares or passions to trouble me, I spent
the entire day closed up alone in a room heated by a stove, where I had all the
leisure to talk to myself about my thoughts. Among these, one of the first was
that I noticed myself thinking about how often there is not so much perfection
in works created from several pieces and made by the hands of various masters as
there is in those which one person has worked on alone. Thus we see that the
buildings which a single architect has undertaken and completed are usually more
beautiful and better ordered than those several people have tried to refurbish
by making use of old walls built for other purposes. That’s why those ancient
cities which were only small villages at the start and became large towns over
time are ordinarily so badly laid out, compared to the regular places which an
engineer has designed freely on level ground. Even though, considering the
buildings in each of them separately, we often find as much beauty in the former
town as in the latter, or more, nonetheless, looking at them as they are
arranged—here a large one, there a small one—and the way they make the
streets crooked and unequal, we say that chance rather than the will of some men
using their reason designed them this way.
And
if one considers that there have always been officials charged with seeing that
private buildings serve as a public ornament, one will readily see that it is
difficult to achieve really fine things by working only with other people's
pieces. Thus, I imagined to myself that people who were semi-savages in earlier
times and who became civilized only bit by bit and created their laws only as
they were compelled to by the extent to which crimes and quarrels bothered them
would not be so well regulated as those who, from the moment they first
assembled, followed the constitution of some prudent legislator.
It
is indeed certain that the state of the true religion, whose laws God alone
created, must be incomparably better ordered than all the others. And, to speak
of human affairs, I believe that if Sparta was in earlier times very prosperous,
that was not on account of the goodness of each of its laws in particular,
seeing that several were very strange and even contrary to good morals, but on
account of the fact that they were devised by only a single man and thus they
contributed towards the same end. Similarly I thought that the knowledge
contained in books, at least those whose reasons are only probable and without
any proofs, was put together and crudely fashioned little by little out of the
opinions of several different people and thus did not approach the truth as much
as the simple reasoning which a man of good sense can make quite naturally
concerning matters of his own experience. In the same way I thought that because
we were all children before we were men and because it was necessary for us to
be governed for a long time by our appetites and our supervisors, who were often
at odds with each other, with neither of them perhaps advising us always for the
best, it is almost impossible that our judgments are as pure and solid as they
would have been if we had had the total use of our reason from the moment of our
birth and had never been led by anything but our reason.
It
is true that we see little point in demolishing all the houses of a city for the
sole purpose of rebuilding them in another way to make the streets more
beautiful. But we do see several people demolish their houses in order to
rebuild them, and, indeed, sometimes they are compelled to do so, when the
houses are in danger of collapsing on their own and when their foundations are
not steady. This example persuaded me that there would probably be little point
for a particular man to draw up a design for reforming a state, changing all of
it from the foundations, overturning it in order to put it up again, or even for
reforming the body of sciences or the order established in the schools for
teaching the sciences. But so far as all the opinions which I had received up to
that point and which I believed credible were concerned, I convinced myself that
the best possible thing for me to do was to undertake to remove them once and
for all, so that afterwards I could replace them either by other better ones or
perhaps by the same ones, once I had adjusted them to a reasonable standard.
And
I firmly believed that by this means I would be successful in conducting my life
better than if I built only on the old foundations and relied only on principles
which I had been persuaded to accept in my youth, without having examined
whether they were true. For, although I recognized various problems with this
approach, these were not without remedy and could not compare to those which
occur in the reforms of the least matters concerning the public. It is too
difficult to re-erect those large bodies if they are thrown down or even to keep
them once they are weakened, and their collapses cannot be anything but very
drastic.
Then,
as far as the imperfections of large public bodies are concerned, if they have
any (and the variety among such bodies alone is sufficient to assure us that
there are several imperfections), habit has no doubt considerably softened these
and has even managed to avoid some problems or corrected a number of them
insensibly, which people's caution could not have managed so well, and finally
the imperfections are almost always easier to bear than changing them would be,
in the same way that the major roads which wind among the mountains gradually
become so smooth and convenient from being used, that it is much better to
follow them than to set out to go more directly by climbing up over the rocks
and right to the bottom of the precipices.
That's
why I cannot approve at all of those muddled and worried temperaments who,
without being summoned by their birth or fortune to the management of public
business, never stop proposing some idea for a new reform in it. If I thought
that there was the slightest thing in this text which would enable someone to
suspect me of this foolishness, I would be very reluctant to allow it to be
published. My intention has never been to do more than try to reform my own
thoughts and to build on a foundation which is entirely my own. And if my work
has pleased me sufficiently to make me show you the model of it here, that's not
because I wish to advise anyone to imitate it. Those to whom God has given more
of his grace will perhaps have loftier intentions, but I fear that this work may
already be too bold for several people. The single resolution to strip away all
the opinions which one has previously absorbed into one's beliefs is not an
example which everyone should follow.
Most
of the world is made up of two sorts of minds for whom such a resolution is not
suitable. First, there are those who, believing themselves more clever than they
are, cannot stop making hasty judgments, without having enough patience to
conduct their thoughts in an orderly way, with the result that, once they have
taken the liberty of doubting the principles they have received and of leaving
the common road, they will never be able to hold to the track which they need to
take in order to proceed more directly and will remain lost all their lives.
Then, there are the ones who, having sufficient reason or modesty to judge that
they are less capable of differentiating truth and falsehood than several others
from whom they can be instructed, must content themselves with following the
opinions of these others rather than searching for better opinions on their own.
As
for me, I would have undoubtedly been among the number of this latter group if I
had only had a single master or if I had known nothing at all about the
differences which have always existed among the opinions of the scholarly. But I
learned from my college days on that one cannot imagine anything so strange and
so incredible that it has not been said by some philosopher and, later, in my
traveling, I learned that those who have views very different from our own are
not therefore barbarians or savages, but that several use as much reason as we
do, or more. I also considered how much the same man, with the same mind, raised
from his infancy on among the French or the Germans, would become different from
what he would have been if he had always lived among the Chinese or the
cannibals, and how, even in our style of dress the same thing which pleased us
ten years ago and which will perhaps please us again ten years from today, now
seems to us extravagant and ridiculous. This being the case, we are clearly
persuaded more by custom and example than by any certain knowledge. Nonetheless,
a plurality of voices is not a proof worth anything for truths which are a
little difficult to discover, because it is far more probable that one man by
himself would have found them than an entire people. Since I could not select
anyone whose opinions it seemed to me preferable to those of other people, I
found myself, so to speak, compelled to guide myself on my own.
But
like a man who proceeds alone and in the shadows, I resolved to go so slowly and
to use so much circumspection in all matters, that if I only advanced a very
short distance, at least I would take good care not to fall. I did not even wish
to begin by rejecting completely any of the opinions which could have slipped
into my beliefs previously without being introduced by reason, before I had
taken up enough time drawing up a plan for the work I was undertaking and
seeking out the best method for arriving at an understanding of everything my
mind was capable of knowing.
When
I was younger, among the branches of philosophy, I had studied a little logic
and, among the subjects of mathematics, geometrical analysis and algebra, three
arts or sciences which looked as if they ought to contribute something to my
project. But in looking at them, I took care, because, so far as logic is
concerned, its syllogisms and most of its other instructions serve to explain to
others what one already knows or even, as in the art of Lully*,
to speak without judgment of things about which one is ignorant, rather than to
learn what they are. Although philosophy does, in fact, contain many really true
and excellent precepts, mixed in with them there are always so many injurious or
superfluous ones that it is almost as difficult to separate them as to draw a
Diana or a Minerva out of a block of marble which has not yet been carved.
Then,
so far as the analysis of the ancients and the algebra of the moderns are
concerned, other than the fact that they deal only with really abstract matters,
which have no apparent use, the first is always so concentrated on considering
numbers that it cannot exercise the understanding without considerably tiring
the imagination, and in the latter one is so subject to certain rules and
symbols that it has been turned into a confused and obscure art which clutters
up the mind rather than a science which cultivates it.
Those
are the reasons why I thought I had to look for some other method which included
the advantages of these three subjects but was free of their defects. And since
a multitude of laws often provides excuses for vices, so that a state is much
better ruled when it has only a very few laws which are very strictly observed,
I thought that, instead of that large number of rules which make up logic, I
would have enough with the four following rules, provided that I maintained a
strong and constant resolution that I would never fail to observe them, not even
once.
The
first rule was that I would not accept anything as true which I did not clearly
know to be true. That is to say, I would carefully avoid being over hasty or
prejudiced, and I would understand nothing by my judgments beyond what presented
itself so clearly and distinctly to my mind that I had no occasion to doubt it.
The
second was to divide each difficulty which I examined into as many parts as
possible and as might be necessary to resolve it better.
The
third was to conduct my thoughts in an orderly way, beginning with the simplest
objects, the ones easiest to know, so that little by little I could gradually
climb right up to the knowledge of the most complex, by assuming the same order,
even among those things which do not naturally come one after the other.
And
the last was to make my calculations throughout so complete and my examinations
so general that I would be confident of not omitting anything.
Those
long chains of reasons, all simple and easy, which geometers have
And
I did not have much trouble finding out the issues which I had to deal with
first. For I already knew that it had to be with the simplest things, the ones
easiest to know. When I thought about how, among all those who had so far
searched for truth in the sciences, it was only the mathematicians who had been
able to find some proofs, that is to say, some certain and evident reasons, I
had no doubt at all that I should start with the same things which they had
examined, although I did not hope for any practical results, other than that
they would accustom my mind to revelling in the truth and not to remain happy
with false reasons. But for all that I did not plan trying to learn all the
particular sciences which people commonly call mathematical. Since I saw that,
even though their objects were different, they all were alike in that they all
agreed they should consider nothing except the various relationships or
proportions among the objects of study found there, I thought that it would be
more valuable if I examined only these proportions in general, assuming only
that they were present in the subjects which would help to provide me knowledge
of them most readily, but without in this way restricting them at all, so that
they could be all the better applied later to every other subject for which they
might be suitable.
Then,
because I observed that, in order to understand these things, I would sometimes
need to consider each one in particular and sometimes only to remember them or
to understand several of them together, I thought that to consider them better
separately, I ought to assume that they were like lines, because I know of
nothing simpler, nothing which I could more distinctly represent to my
imagination and my senses. But in order to remember them or to understand
several of them together, I had to explain them by some formulas as short as
possible and, by this means, I would borrow all the best elements of analytic
geometry and algebra and correct all the defects of one by the other.
As
a matter of fact, I venture to say that the precise observation of these few
precepts which I had selected gave me such a facility at disentangling all the
questions which these sciences cover, that in the two or three months that I
used them to examine these questions, starting with the simplest and the most
general, letting each truth I found serve as a rule which I could use afterwards
to find others, not only did I resolve several problems which I had previously
judged very difficult, but it also seemed to me towards the end that I could
determine, even with those questions where I was ignorant, the way to resolve
them and the extent to which such resolution was possible. In saying this,
perhaps I will not appear too vain if you consider that, since there is only one
truth for each thing, whoever finds it knows as much as one can know about it
and that, for example, a child instructed in arithmetic, having made an addition
following the rules, can be confident of having found, so far as the sum he is
examining is concerned, everything that the human mind can find out. For the
method which teaches one to follow the true order and to count exactly all the
relevant details in what one is looking for contains everything which gives
certainty to the rules of arithmetic.
But
what pleased me the most with this method was that with it I was confident of
using all my reason, if not perfectly, at least as well as was in my power. In
addition, I felt, as I applied it, that my mind was accustoming itself gradually
to think more clearly and distinctly about its objects, and because I had not
restricted this method to one matter in particular, I was hopeful that I could
apply it just as usefully to difficulties in the other sciences as I had applied
it to those in algebra.
But
for all that, I did not venture to try immediately examining all those
scientific problems which presented themselves. For that would have been
contrary to the order which my method prescribed. But I noticed that the
principles of science all had to be borrowed from philosophy, a subject in which
I no longer found anything certain. So I thought that, before anything else, I
should attempt to establish such principles and that, since this was the most
important matter in the world, where one had to be most fearful of over-hasty
and biased judgments, I would not try to get through it until I had reached an
age considerably more mature than I was then at twenty-three and until I had
used a lot more time preparing myself, weeding out of my mind all the bad
opinions which I had accepted before that time, as well as collecting
experiences which later could be the subject matter of my reasoning, always
practising the method which I had set for myself in order to keep improving
myself in these matters.
Part
Three
Finally,
before one starts to rebuild the lodgings where one lives, it is not sufficient
to knock them down and provide for materials and architects or to work on the
architecture oneself, having, in addition to that, carefully drawn up a design.
One must also provide oneself with some other place where one can lodge
comfortably during the time one works on the building. Thus, in order not to be
irresolute in my actions while my reason obliged me to be so in my judgments and
in order to be able to live from then on as happily as I could, I drew up for
myself a provisional morality, consisting of only three or four maxims, which I
wish to share with you.
The
first was to obey the laws and the customs of my country, constantly holding to
the religion which God gave me the grace to be instructed in since my childhood
and governing myself in all other things in accordance with the most moderate
opinions, the ones furthest removed from excess, which were commonly accepted
and practised by the most sensible of those people among whom I was living.
Since, from that point on, I began to estimate my own views as worthless,
because I wished to subject them all to examination, I was confident that I
could not do better than to follow those of the most sensible people.
And
even though there might perhaps be people just as sensible among the Persians or
the Chinese as among us, it seemed to me that the most practical thing would be
for me to guide myself by those among whom I had to live and that, in order to
understand their real opinions, it would be better for me to pay attention to
what they practised rather than to what they said, not only because, given the
corruption of our morals, there are few people who are willing to say what they
believe, but also because several are themselves ignorant of what they believe.
For the act of thinking by which one believes in something is different from the
act of thinking by which one understands that one believes it, and one of these
separate acts frequently appears without the other.
Moreover,
among several opinions equally well received, I chose only the most moderate
ones, as much because such opinions are always the most convenient to practice
and probably the best, for all excess is usually bad, as because they would be
less likely to turn me away from the true road, if I fell short, than if I had
chosen one of the extremes when it was the other one which I should have
followed.
And
I especially included among what was excessive all promises by which one reduces
one's liberty. Not that I disapprove of laws which, in an attempt to remedy the
fickleness of feeble minds, permit people with a good plan or even an
indifferent arrangement for security in business to make vows or contracts
obliging them to maintain their provisions. But because I didn't see anything in
the world which remained always in the same condition and, in my particular
case, because I promised myself that I would increasingly perfect my judgments
and not make them worse, I would have thought I was committing a great error in
good sense if, because I then approved of something, I obliged myself to
continue to take it as something good later on, when it had perhaps ceased to be
so or when I had ceased to value it as something good.
My
second maxim was to be as constant and as resolute in my actions as I could, and
to follow the most doubtful opinions, once I had settled on them for myself,
with no less constancy than if they had been very sure, imitating in this matter
travelers who, finding themselves lost in some forest, should not wander around,
shifting direction this way and that; even less should they stop in one place;
they should move on always as straight as they can in the same direction and not
change it for inadequate reasons, even though at the beginning it was perhaps
only chance which led to their choice of direction. For in this way, if they do
not come out exactly where they want to, they will at least end up arriving
somewhere where they will probably be better off than in the middle of a forest.
And
because the actions of life often brook no delay, it is certainly true that,
when it is not in our power to determine the truest opinions, we ought to follow
the most probable ones, and even when we see no difference in probability among
this group of truths or that one, nevertheless, we have to decide on some for
ourselves and then to consider them, not as something doubtful with regard to
the practical matter at hand, but as manifestly true and very certain, because
the reason which made us choose them has these qualities. This method was able
from then on to relieve me of all the regrets and remorse which usually upset
the consciences of those weak and wavering minds which permit themselves to work
unevenly with things which they accept as good but which they later judge to be
bad.
My
third maxim was to try always to overcome myself rather than fortune and to
change my desires rather than the order of the world, and generally to get in
the habit of believing that there is nothing which is entirely within our power
except our thoughts, so that after we have done our best concerning those things
which lie outside of us, everything which our attempt fails to deal with is, so
far as we are concerned, absolutely impossible.
That
alone seemed to me to be sufficient to prevent me from desiring anything in
future which I could not achieve and thus to make me happy. For since our will
has a natural tendency to desire only things which our understanding represents
as in some way possible, it is certain that if we think about all the good
things which are outside of us as equally distant from our power, we would no
more regret missing those whose loss is due to our birth, when we are deprived
by no fault of our own, than we would regret not possessing the kingdoms of
China or Mexico. By making, as the saying goes, a virtue of necessity, we would
not desire health when we are sick or freedom when we are in prison, any more
than we now desire to have either a body made of some material less subject to
decay than diamonds or wings to fly, like the birds.
But
I admit that there is a need for a long discipline and frequently repeated
meditation in order to accustom oneself to looking at everything from this point
of view. And I believe that this is the principal secret of those philosophers
who have been able in earlier times to escape from the demands of empire and
fortune and who, despite pains and poverty, could rival their gods in happiness.
For, constantly busy thinking about the limits prescribed for them by nature,
they persuaded themselves so perfectly that nothing was in their power except
their thoughts, that that alone would be enough to prevent them from having any
affection for other things, and they acquired such an absolute control over
their thoughts that they found in that process reason to think themselves more
rich and more powerful and more free and more happy than any other men, who,
because they did not possess this philosophy, never had the same control over
everything they desired, no matter how favoured they might be by nature and
fortune.
Finally,
to conclude these moral precepts, I advised myself to draw up a review of the
various occupations which men have in this life, in an attempt to make a choice
about the best and, without wanting to say anything about the others, I thought
that I could not do better than to continue in the very occupation I was engaged
in, that is, using all my life to cultivate my reason and to progress as far as
I could in a knowledge of the truth, following the method which I had prescribed
for myself. I experienced such extreme contentment once I started using this
method that I did not think that one could find anything more sweet and
innocent. Since every day I discovered through this method some truths which
seemed to me sufficiently important and commonly unknown to other men, the
satisfaction I got so filled my mind that nothing else affected me.
Moreover,
the three maxims mentioned above were founded only for the plan I had to
continue my self-instruction. For since God has given each one of us some light
to distinguish truth from falsehood, I would not have thought I could remain
content with other people's opinions for one moment, if I had not set out to use
my own judgment to examine them when the time was right, and I would not have
known how to free myself from scruples in following these opinions, if I had not
hoped that I would not, in the process, lose any opportunity to find better
ones, in cases where these existed. Finally I would not have known how to limit
my desires nor how to rest content, if I had not followed a road by which I
believed I could be confident of acquiring all the knowledge I was capable of. I
thought by the same means I could acquire all the true benefits I was capable of
obtaining, all the more so since our will tends to follow or to fly away from
only those things which our understanding has represented to it as good or bad.
So in order to act well it is sufficient to judge well, and to judge as well as
one can is sufficient to enable one to do one's best, that is, to acquire all
the virtues, along with all the other benefits which one can get, and when one
is certain that that is the case one could not fail to be happy.
After
assuring myself of these maxims in this manner and storing them away, along with
the truths of the faith, which have always been first in my beliefs, I judged
that, so far as all the rest of my opinions were concerned, I could freely set
about dispensing with them. Since I hoped to be able to arrive at my goal more
easily by talking with men rather than staying any longer closed up in the room
with the stove where I had had all these thoughts, before that winter was over
and done with, I set about my travels again.
And
in all the nine years following I did nothing else but roll around here and
there in the world, trying to be a spectator rather than an actor in all the
comedies playing themselves out. By reflecting on each matter, in particular on
what there was which could render it suspect and give us an opportunity to make
mistakes, I rooted out from my mind all the errors which could have slid into it
in the previous years. Not that in the process I copied the sceptics, who doubt
only for the sake of doubting, and pretend that they are always irresolute. For
my entire plan, by contrast, tended only to make me confident about throwing
away the shifting ground and the sand, in order to find the rock or the
sedimentary clay.
This
gave me considerable success, it seems to me, inasmuch as in my attempts to
discover the falsity or the uncertainty of the propositions I examined, not by
weak conjectures, but by clear and confident reasoning, I came across nothing so
doubtful that I did not always draw some fairly certain conclusion from it, even
if that conclusion was that it contained nothing certain. Just as when we tear
down an old lodging, we usually keep the scrap to use in building a new
structure, so, as I destroyed all those opinions of mine which I judged poorly
grounded, I made various observations and acquired several experiences which
were of use to me later in establishing more certain ones.
In
addition, I continued to practice the method which I had set for myself. For
apart from the fact that I took care, in general, to conduct all my thinking
according to the rules, from time to time I set aside a few hours which I used
to apply the method to mathematical difficulties in particular, or even to some other difficulties as well, ones which I could frame in a manner
somewhat similar to those in mathematics, stripping from them all the principles
of the other sciences which I did not find sufficiently strong, as you will see
I have done in the several which are explained in this volume.*
Thus,
without living in a way apparently different from those who have nothing else to
do but spend a sweet and innocent life studying how to separate pleasures from
vices and enjoying their leisure by making use of all honest entertainments
without getting bored, I did not fail to follow my plans and to benefit from the
knowledge of the truth, perhaps more so than if I had only read books or
associated with men of letters.
However,
these nine years passed by before I had yet taken any stand concerning the
difficulties which are usually matters of dispute among the scholars. Nor had I
started to seek the foundations of any philosophy more reliable than common
philosophy. The example of several excellent minds who had earlier had the same
idea but who, it seemed to me, had not succeeded, made me imagine such great
difficulties that I would perhaps not have ventured to undertake it so quickly,
if I had not seen that some people had already spread the rumour that I had
concluded my work. I don't know what to say about the basis for this rumour. And
if I contributed something to it by my conversations,
But having a heart sufficiently good not to wish people to take me for
someone other than the man I am, I thought it necessary to attempt by every
means to make myself worthy of the reputation which people ascribed to me. For
exactly eight years this desire made me resolve to distance myself from all
those places where there might be people I know and to retire here, in a country
where the long duration of the war has established such order that the armies
which maintain it appear to serve only to enable the people to enjoy the fruits
of peace with even more security and where, among the crowd of a great and very
active people, who are more careful about their own affairs than curious about
those of other people, with no lack of any commodities present in more
frequently visited towns, I was able to live retired in solitude, just as if I
were in the most isolated deserts.
Part
Four
I
don't know if I should share with you the first meditations which I made there,
for they are so metaphysical and so out of the ordinary that they will perhaps
not be to everyone's taste. However, in order that people may be able to judge
if the foundations which I set are sufficiently strong, I find myself in some
way compelled to speak of them. For a long time previously I had noticed that
where morals are concerned it is necessary sometimes to follow opinions which
one knows are extremely uncertain as if they are indubitable, as mentioned
above. But since at that time I wanted only to carry out research into the
truth, I thought I must do the opposite and reject as absolutely false
everything about which I could imagine the least doubt, in order to see if there
would be anything totally indisputable remaining after that in my belief.
Thus,
because our senses deceive us sometimes, I was willing to assume that there was
nothing which existed the way our senses present it to us. And because there are
men who make mistakes in reasoning, even concerning the most simple matters of
geometry, and who create para-logisms, and because I judged that I was subject
to error just as much as anyone else, I rejected as false all the reasons which
I had taken earlier as proofs. Finally, considering that all the same thoughts
which we have when awake can also come to us when we are asleep, without there
being truth in any of them at the time, I determined to pretend that everything
which had ever entered my mind was no more true than the illusions of my dreams.
But
immediately afterwards I noticed that, while I wished in this way to think
everything was false, it was necessary that I—who was doing the thinking—had
to be something. Noticing that this truth—I think; therefore, I am—was so
firm and so sure that all the most extravagant assumptions of the sceptics would
not be able to weaken it, I judged that I could accept it without scruple as the
first principle of the philosophy I was looking for.
Then
I examined with attention what I was, and I saw that I could pretend that I had
no body and that the world and the place where I was did not exist, but that, in
spite of this, I could not pretend that I did not exist. By contrast, in the
very act of thinking about doubting the truth of other things, it very clearly
and certainly followed that I existed; whereas, if I had once stopped thinking,
even though all the other things which I had imagined were real, I would have no
reason to believe that I existed. From that I recognized that I was a substance
whose essence or nature is only thinking, a substance which had no need of any
location and did not depend on any material thing, so that this “I,” that is
to say, the soul, by which I am what I am, is entirely distinct from the body
and is even easier to know than the body, and that, even if the body were no
longer there, the soul could not help being everything it is.
After
that, I considered in general what is necessary for a proposition to be true and
certain, for since I had just found one idea which I knew to be true and
certain, I thought that I ought also to understand what this certitude consisted
of. And having noticed that in the sentence "I think; therefore, I am"
there is nothing at all to assure me that I am speaking the truth, other than
that I see very clearly that in order to think it is necessary to exist, I
judged that I could take as a general rule the point that the things which we
conceive very clearly and very distinctly are all true. But that left the single
difficulty of properly noticing which things are the ones we conceive
distinctly.
After
that, I reflected on the fact that I had doubts and that, as a result, my being
was not completely perfect, for I saw clearly that it was a greater perfection
to know than to doubt. I realized that I should seek out where I had learned to
think of something more perfect than I was. And I concluded that obviously this
must be something with a nature which was, in effect, more perfect.
As
for the thoughts which I had of several other things outside of me, like the
sky, the earth, light, heat, and a thousand others, I was not worried about
knowing where they came from, because I didn't notice anything in them which
seemed to me to make them superior to myself. Thus, I was able to think that, if
they were true, that was because of their dependence on my nature, in so far as
they had some perfection and, if they were not true, I held them from nothing,
that is to say, that they were in me because I had some defect.
But
that could not be the same with the idea of a being more perfect than mine. For
to hold that idea from nothing would be manifestly impossible. And because it is
no less unacceptable that something more perfect should be a consequence of and
dependent on something less perfect than that something should come from
nothing, I could not derive this idea from myself. Thus, I concluded that the
idea had been put in me by a nature which was truly more perfect than I was,
even one which contained in itself all the perfections about which I could have
some idea, that is to say, to explain myself in a single phrase, a nature which
was God.
To
this I added the fact that, since I know about some perfections which I do not
have, I was not the only being which existed (here I will freely use, if you
will permit me, the language of the schools). But it must of necessity be the
case that there was some other more perfect being, on whom I depended and from
whom I had acquired all that I had. For if I had been alone and independent of
everything else, so that I derived every idea, however little, which I shared of
the perfect being from myself, I would have been able to have from myself, for
the same reason, all the additional perfections which I knew I lacked, and thus
be myself infinite, eternal, immutable, all knowing, all powerful, and finally
have all the perfections which I could observe as present in God.
For,
following the reasoning which I have just made, to know the nature of God, to
the extent that my reasoning is able to do that, I only had to think about of
all the things of which I had some idea within me and consider whether it was a
sign of perfection to possess them or not. And I was confident that none of
those ideas which indicated some imperfection were in God, but that all the
others were there, since I perceived that doubt, inconstancy, sadness, and
similar things could not be in God, in view of the fact that I myself would have
been very pleased to be free of them.
Then,
in addition, I had ideas about several sensible and corporeal things. For
although I supposed that I was asleep and that everything which I saw or
imagined was false, nonetheless I could not deny that the ideas had truly been
in my thoughts. But because I had already recognized in me very clearly that
intelligent nature is distinct from corporeal nature, when I considered that all
composite natures indicate dependency and that dependency is manifestly a
defect, I judged from this that God's perfection could not consist of being
composed of two natures, and that thus He was not, but that if there were some
bodies in the world or even some intelligences or other natures which were not
completely perfect, their being had to depend on God's power, in such a way as
they could not subsist for a single moment without Him.
After
that I wanted to look for other truths, and I proposed to myself the subject
matter of geometricians, which I understood as a continuous body or a space
extended indefinitely in length, width, and height or depth, divisible into
various parts, which could have various figures and sizes and be moved or
transposed in all sorts of ways, for the geometricians assume all that in their
subject matter. I glanced through some of their simplest proofs, and having
observed that this grand certainty which all the world attributes to them is
founded only on the fact that they plan these proofs clearly, following the rule
which I have so often stated, I notice also that there is nothing at all in
their proofs which assures me of the existence of their objects. So, for
example, I do see that, if we assume a triangle, it must the case that its three
angles are equal to two right angles, but, in spite of that, I don't see
anything which assures me that there is a triangle in the world. But, by
contrast, once I returned to an examination of the idea which I had of a perfect
being, I found that that being contains the idea of existence in the same way as
the fact the three angles of a triangle are equal to two right angles is
contained in the idea of a triangle, or that in a sphere all the parts are
equidistant from the centre, or something even more evident, and that, as a
result, it is at just as certain that God, this perfect being, is or exists as
any geometric proof can be.
But
the reason there are several people who persuade themselves that there are
difficulties in understanding this and even knowing what their soul is, as well,
is that they never raise their minds above matters of sense experience and that
they are so accustomed not to consider anything except by imagining it, which is
a way of thinking in particular of material things, so that everything which is
not imaginable seems to them unintelligible. This point is obvious enough in the
fact that even the philosophers in the schools maintain the axiom that there is
nothing in the understanding which has not first of all been in the senses. But
it is certain that the ideas of God and the soul have never been present in
sense experience. It seemed to me that those who want to use their imagination
to understand these things are acting just as if they want to use their eyes to
hear sounds or smell odours, except that there is still this difference, that
the sense of sight provides us no less assurance of the truth of what it sees
than do the sense of smell or hearing; whereas, neither our imagination nor our
senses can assure us of anything unless our understanding intercedes.
Finally,
if there are still some people who are insufficiently persuaded of the existence
of God and their soul by the reasons I have provided, I'd like them to know that
everything else which they perhaps are more confident about in their thinking,
like having a body and knowing that there are stars and an earth, and things
like that, are less certain than God's existence. For although one has a moral
assurance about these things, something which makes doubting them appear at
least extravagant, nonetheless it also seems at least unreasonable, when a
question of metaphysical certainty is involved, for someone to deny that there
is sufficient material here to make one not completely confident, for we notice
that one can imagine in the same way while sleeping that one has a body and that
one sees other stars and another earth, without such things existing.
For
what is the source of our knowledge that the thoughts which come while dreaming
are false, rather than the others, seeing that often they are no less lively and
distinct? And if the best minds study this matter as much as they please, I do
not think that they will be able to give any reason which will be sufficient to
remove this doubt unless they presuppose the existence of God. First of all, the
very principle which I have so often taken as a rule—only to recognize as true
all those things which we conceive very clearly and very distinctly—is
guaranteed only because of the fact that God is or exists, that He is a perfect
being, and that everything which is in us comes from Him. From that it follows
that our ideas or notions, being real things which come from God, to the extent
that they are clear and distinct, in that respect cannot be anything but true.
Consequently, if we often enough have some ideas or notions which contain
something false, that can only be those which contain some confusion and
obscurity, because in this they participate in nothing, that is to say, they are
so confused in us only because we are not completely perfect.
And
evidently it is no less repugnant that falsity or imperfection, in itself,
should come from God than that utility or truth should come from nothingness.
But if we did not know that everything real and true within us came from a
perfect and infinite being, then no matter how clear and distinct our ideas
were, we would not have a single reason to assure us that they had the
perfection of being true.
Now,
after the knowledge of God and the soul in this way has made us certain of this
rule, it is really easy to see that the dreams which we imagine while asleep
should not, in any way, make us doubt the truth of the thoughts we have while
awake. For if it happened, even while we were sleeping, that we had some really
distinct idea, as, for example, in the case of a geometer inventing some new
proof, the fact that he is asleep does not prevent it from being true, and as
for error, it doesn't matter that the most common dreams we have, which consist
of representing to us various objects in the same way as our external senses do,
can give us occasion to challenge the truth of such ideas, because these ideas
can also mislead us often enough without our being asleep, as, for example, when
those people suffering from jaundice see all objects as yellow, or when the
stars or other bodies at a great distant appear to us much smaller than they
are.
For,
finally, whether we are awake or asleep, we should never allow ourselves to be
persuaded except by the evidence of our reason. And people should note that I
say of our reason and not of our imagination or of our senses, since even though
we see the sun very clearly, we should not for that reason judge that it is only
the size which we see, and we can easily imagine distinctly the head of a lion
mounted on the body of goat, without having to conclude, because of that, there
is a chimera in the world*: for reason
does not dictate to us that what we see or imagine in this way is true, but it
does dictate to us that all our ideas or notions must have some foundation in
truth, for it would not be possible that God, who is completely perfect and
totally truthful, put them in us without that. Because our reasoning is never so
evident or complete during sleeping as while we are awake, although then
sometimes our imaginations are as vital or explicit, or more so, reason also
dictates to us that our ideas cannot all be true, because we are not completely
perfect—those which contain the truth must without exception come in those we
experience while awake rather than in those we have while asleep.
Part
Five
I
would be very pleased to continue and make you see here all the chain of other
truths which I deduced from these first ones. But because that would require
that I talked of several questions which are controversial among scholars,
things I do not want to get mixed up with, I think it would be better to refrain
from that and speak only in general about what these matters are, so that the
more learned can judge if it would be useful for the public to be informed about
more particular details.
I
always lived firm in the resolution that I had taken not to assume any other
principle than the one which I have just used to demonstrate the existence of
God and the soul, and to accept nothing as true which did not seem to me more
clear and more certain than the proofs of geometry had seemed to me previously.
Nonetheless, I venture to say that, not only did I find a way of satisfying
myself in a short time concerning all the difficult principles which people are
accustomed to deal with in philosophy, but also I noticed certain laws which God
has established in nature. Since He has imprinted ideas of these laws in our
souls, after we have reflected on them sufficiently, we cannot doubt that they
are precisely observed in everything which exists or which acts in the world.
Then, as I considered the consequence of these laws, it seemed to me that I had
discovered several truths more useful and more important than everything which I
had previously learned or even hoped to learn.
But
since I attempted to explain the principles in a treatise which certain
considerations prevented me from publishing, I do not know how better to make
them known than stating here in summary form what that treatise contains. Before
writing that text, I had the intention of including in it all that I thought I
knew concerning the nature of material things. But just as painters cannot
portray equally well in a flat picture all the various surfaces of a solid body
and choose one of the main surfaces, which they set by itself facing the light
and, by placing the others in shadows, do not show anything more than one can
see by looking at them, in the same way, fearing that I could not put in my
discourse everything I had in my thoughts, I tried only to reveal there fairly
fully what I understood about light, and then at the appropriate time, to add
something about the sun and the fixed stars, because almost all light comes from
them, about the heavens, because they transmit light; about the planets, comets,
and the earth, because they reflect light, and in particular about all the
bodies on earth, because they are coloured, or transparent, or luminous, and
finally about man, because he is the one who looks at these things.
Even
so, in order to shade in all these things a little and to be able to speak more
freely of what I was judging, without being obliged to follow or to refute
received opinions among the learned, I resolved to leave everyone here to their
disputes and to speak only of what would happen in a new world, if God now
created somewhere in imaginary space enough material to compose it, and if He
set in motion, in a varied and disorderly way, the various parts of this
material, so that it created a chaos as confused as poets could make it, and
then afterwards He did nothing other than lend His ordinary help to nature and
allow it to act according to the laws which He established.
So
first of all I described this material and tried to picture it in such a way
that there is nothing in the world, it seems to me, clearer and more
intelligible, except what has been said from time to time about God and the
soul. For I even explicitly assumed that in the world there were none of those
forms or qualities which people argue about in the schools, nor, in general,
anything the knowledge of which was not so natural to our souls that we could
not even pretend to remain ignorant of it.
In
addition, I made known the laws of nature, and without basing my reasoning on
any principle other than the infinite perfections of God, I tried to demonstrate
all of these laws about which one could entertain any doubts, to show that they
are such that, although God could have created several worlds, there would not
be one where these failed to be observed. After that, I showed how the greatest
part of material in chaos would have to, as a result of these laws, organize and
arrange itself in a certain way which made it similar to our heavens, how, in so
doing, some of its parts must have made up an earth and some parts planets and
comets, and some other parts a sun and fixed stars.
And
at this point, dwelling on the subject of light, I explained at some length the
nature of light which must be found in the sun and the stars, how from there it
crossed in an instant the immense distances of heavenly space, and how it is
reflected from the planets and comets towards the earth. To this I added several
things concerning the material, the arrangement, the movements, and all the
various qualities of our heavens and the stars. Consequently, I thought I had
said enough about these matters to make known the fact that one observes nothing
in these features of this world which must not, or at least could not, appear
entirely similar to those of the world which I described.
From
there I went on to speak in particular about the earth, about how, although I
had expressly assumed that God had placed no heaviness in the material of which
it is composed, all its parts could not help tending to move precisely to its
centre, how, having water and air on its surface, the arrangement of the heavens
and the stars, and particularly of the moon, had to create on earth an ebb and
flow similar in all its features to the ones we see in our oceans, and, beyond
that, a certain flow in the water as well as in the air, from east to west, like
the one we observe between the tropics, how the mountains, seas, fountains, and
rivers can naturally form out of that, how earth's metals come into the mines,
and how the plants on earth grow in the fields, and, in general, how all the
things we call mixed or composite could be produced on earth.
And,
among other things, because there is nothing on earth which produces light
except fire (other than the stars), I studied to understand clearly everything
associated with the nature of fire, how it arises, how it is nourished, how
sometimes it has heat without light and sometimes light without heat, how it can
introduce various colours in different bodies, as well as various other
qualities, how it melts some things and makes others harder, how it can consume
almost everything or convert it into ash and smoke, and finally how, out of
these cinders, simply by the violence of its actions, it makes glass. For this
transformation of cinders into glass seemed to be as wonderful as anything else
which happens in nature, and I took particular pleasure in describing it.
However,
I don't want to suggest from all these things that this world was created in the
fashion which I was proposing. For it is much more probable that God made the
world from the beginning just what it had to be. But it is certain, and this is
an opinion commonly received among theologians, that the actions by which God
now preserves the world are exactly the same as the method by which He created
it, in such a way that even if He did not give it at the start any form other
than a chaos, providing that He had first established the laws of nature and had
given His assistance, so that it would act as it usually does, we can believe,
without denying the miracle of creation, that because of these facts all purely
material things would have been able, over time, to become the way we now
observe them, and their nature is much easier to conceive when one sees them
born gradually in this way than if one thinks of them only as made all at once.
From
the description of the inanimate bodies and of plants, I moved onto the bodies
of animals and especially the body of man. But because I did not yet have
sufficient knowledge to speak of that in the same way as of other things, that
is to say, to speak of effects in terms of causes, by revealing the seeds and
the methods by which nature had to produce them, I contented myself with
assuming that God formed the human body completely like one of our own, both the
external shape of its limbs and the arrangement of its inner organs, without
making them of any material other than the one which I had described and
without, at the start, placing in that body any reasonable soul or any other
thing to serve the body as a vegetative or sensitive soul, except that He
kindled in its heart one of those fires without light which I had already
explained and which I conceived as in no way different in its nature from the
fire which heats hay when it is closed up in a sack or which makes new wines
bubble when they are allowed to ferment after crushing. For, by examining the
functions which, as a result of this assumption, could be present in this body,
I found precisely all those which could be in us without our thinking about
them, and thus without any contribution from our soul, that is to say, the
distinct part of the body whose nature is solely to think (as I have said
above), the functions which we can say are all those in which the animals
without reason are similar to us. But in doing this, I could not find any of
those which, because they are dependent on thought, are the only ones which
pertain to us, as men; whereas, I found all of them afterwards, once I assumed
the God had created a reasonable soul and joined it to this body in the
particular way which I described.
But
so that you can see how I dealt with this material, I want to put in here the
explanation for the movement of the heart and the arteries, the first and the
most universal thing which one observes in animals. From that one will easily
assess what one should think of all the others. And so that people have less
difficulty understanding what I am going to say, I would like those who are not
versed in anatomy to take the trouble, before reading this, to have the heart of
some large animal with lungs dissected in front of them. For it is in all
respects quite similar to the heart in man. And I would like them to have
demonstrated to them the two chambers or cavities which are in that heart.
First,
there is one chamber on its right side, to which two very large tubes are
attached, that is, the vena cava, which is the principal receptacle of
blood, as it were, the trunk of the tree of which all the other veins of the
body are the branches, and the vena arteriosa*,
which has, with that label, been poorly named, because it is, in fact, an
artery, the one which, originating at the heart, divides up, after leaving the
heart, into several branches, which go out to distribute themselves throughout
the lungs. Then there is the chamber on the left side of the heart, to which, in
the same way, two tubes are attached, which are as large or larger than the ones
just mentioned: that is, the venous artery, which is also misnamed, because it
is nothing but a vein which comes from the lungs, where it is divided into
several branches interwoven with those from the arterial vein and with those
associated with the tube called the windpipe, through which air enters for
respiration; and the large artery which, leaving the heart, sends its branches
throughout the body.
I
would also like someone to point out carefully to them the eleven small strips
of skin which, just like small gates, open and close the four openings in these
two chambers, that is, three at the entry of the vena cava, where they
are so arranged that they cannot in any way prevent the blood contained in the vena
cava from flowing into the right chamber of the heart and, at the same time,
effectively prevent its ability to flow out; three gates at the entry of
arterial vein, which, being arranged in precisely the opposite way, easily allow
the blood in this chamber to move toward the lungs but do not allow the blood in
the lungs to return to that chamber of the heart.
Then,
in the same way, there are two other strips of membrane at the opening to the
venous artery which allow the blood from the lungs to flow towards the left
chamber of the heart, but prevent its return, and there are three at the entry
of the great artery which allow blood to leave the heart but prevent it from
returning there. There is no need to seek for any reason for the number of these
membranes, beyond the fact that since the venous artery is an oval, because of
its location, it can be readily closed with two; whereas, since the others are
round, they can be more easily closed with three.
In
addition, I would like people to notice that the large artery and the arterial
vein have a composition much harder and firmer than the venous artery and the vena
cava, that these last two get bigger before entering the heart and there
make a structure similar to small sacks, called the auricles of the heart, which
are composed of flesh like that of the heart, that there is always more heat in
the heart than in any other place in the body; and finally that, if any drop of
blood enters its cavities, this heat in the heart is capable of making this drop
quickly swell and expand, just as all liquors generally do when one lets them
fall drop by drop into some really hot container.
After
all that, I have no need to say anything to explain the movement of the heart,
other than the following: when its cavities are not full of blood, then
necessarily blood flows from the vena cava into the right chamber and
from the venous artery into the left, because these two blood vessels are always
full and
And,
continuing to become increasingly thinner, the drops of blood push against and
open the six other small gates which stand at the opening of the two other
vessels, through which they flow out, in this way causing all the branches of
the arterial vein and great artery to expand, almost at the same instant as the
heart, which immediately afterwards contracts, as do the arteries as well,
because the blood which has entered them gets colder again, and their six small
gates close once more. Then the five valves on the vena cava and the
venous artery re-open, and allow passage of two more drops of blood, which, once
more, make the heart and the arteries expand, just as in the preceding steps.
And because the blood which enters the heart in this manner passes through these
two small sacks called auricles, this motion causes the movement of the auricles
to be the opposite of the heart's movement—they contract when the heart
expands.
As
for the rest, so that those who do not understand the force of mathematical
proofs and who are not accustomed to distinguishing true reasons from probable
reasons do not venture to deny this matter without examining it, I wish to
advise them that this movement which I have just explained is as necessarily a
result of the mere arrangement of the organs which one can see in the heart with
one's own eyes and of the heat which one can feel there with one's fingers and
of the nature of blood which one can recognize from experience, as the movement
of a clock is necessarily a result of the force, the placement, and the shape of
its counter-weights and wheels.
But
if someone asks how the blood in the veins does not exhaust itself as it flows
continually into the heart in this way and how the arteries are not overfilled
because all the blood which passes through the heart goes into them, there's no
need for me to say anything in reply other than what has already been written by
an English doctor, to whom we must give the honour of having broken the ice in
this area and of being the first to teach that there are several small passages
at the extremities of the arteries through which the blood which they receive
from the heart enters into the small branches of the veins, from where it
proceeds to move once again towards the heart, so that its passage is nothing
other than a constant circulation.*
This
point is really well demonstrated by the common experience of surgeons who,
having bound up an arm moderately tightly above a place where they have opened a
vein, cause the blood to flow out more abundantly than if they had not tied the
arm. And the opposite happens if they place the binding
For
it is clear that the binding, when moderately tight, can only prevent the blood
which is already in the arm from returning towards the heart by the veins, but
in doing that the binding does not stop the blood from continuing to flow to the
place from the arteries, because the arteries are situated below the veins and
because the skin of the arteries, being harder, is less easy to press down.
Thus, the blood which comes from the heart tends to move with more force through
the arteries towards the hand than it does in returning from the hand towards
the heart through the veins. And because this blood leaves the arm by the
opening in one of the veins, it must necessarily be the case that there are some
passages below this binding, that is to say, towards the extremities of the arm,
through which it can come there from the arteries.
Harvey
also demonstrates really well what he says about the flow of blood through
certain small membranes which are so arranged in various places along the veins
that they do not allow blood to move in the veins from the middle of the body
towards the extremities, but only to return from the extremities towards the
heart. Moreover, he demonstrates this by an experiment which shows that all the
blood which is in the body can leave it in a very little time by a single
artery, if it is cut, even more so if it has been tightly bound really close to
the heart and cut between the heart and the binding, so that one simply could
not imagine any explanation other than that the blood flowing out is coming from
the heart.
But
there are several other things which attest that the true cause of this movement
of blood is as I have described it. For, firstly, the difference which one
notices between the blood which comes from the veins and the blood which flows
out of the arteries could come about only if the blood is rarefied and, as it
were, distilled in passing through the heart. It is more subtle, more lively,
and warmer immediately after leaving the heart, that is to say, in the arteries,
than it is shortly before entering the heart, that is to say, when it is in the
veins. And if one pays attention, one will find that this difference is only
readily apparent close to the heart and not so evident in places which are more
distant from it.
Then,
the hardness of the skins making up the arterial vein and the large artery shows
sufficiently well that the blood beats against them with greater force than it
does against the skin of the veins. And why would the left chamber of the heart
and the great artery be more ample and larger than the right chamber and the
arterial vein, if it were not for the fact that the blood of the venous artery,
which has only been in the lungs since passing through the heart, is more subtle
and more strongly and more easily rarefied than the blood which comes
immediately from the vena cava?
And
what could doctors diagnose by testing the pulse, if they did not know, in
keeping with the fact that blood changes its nature, that it can be rarefied by
the heat of the heart more or less strongly and more or less quickly than
before? And if one examines how this heat is transferred to the other limbs, is
it not necessary to admit that it is by means of the blood, which, passing
through the heart, is re-heated and from there spreads throughout the body?
That's the reason why, if one takes blood from some part of the body, in that
very process one takes the heat, and even if the heart were as hot as a burning
fire, it would not be sufficient to re-heat the feet and the hands as much as it
does, if it did not continually send new blood there.
From
this we also understand that the true purpose of respiration is to bring
sufficient fresh air into the lungs to ensure that the blood which comes from
the right chamber of the heart, where it has been rarefied and, as it were,
changed into vapour, thickens and changes back again into blood, before falling
back into the left chamber, without which it would not be fit to serve as
nourishment for the fire there. What confirms this is that we observe that the
animals which have no lungs also have only one cavity in the heart and that
children, who cannot use their lungs while they are closed up in their mother's
womb, have an opening through which blood flows from the vena cava into
the left cavity of their hearts and a passage by which the blood comes from the
arterial vein into the large artery without passing through the lungs.
Next,
how would digestion take place in the stomach, if the heart did not send heat
there through the arteries and with that some of the more easily flowing parts
of the blood which help to dissolve the food we have sent there? And the action
which converts the juice of this food into blood—surely that is easy to
understand, if one considers that it is distilled, as it passes and re-passes
through the heart, perhaps more than one or two hundred times each day?
What
else do we need to explain nutrition and the production of the various humours
in the body, other than to say that the force with which the blood, as it gets
rarefied, passes from the heart towards the extremities of the arteries, brings
it about that some portions of it stop among those parts of the limbs where they
are, and there take the place of some other parts which the blood pushes away,
and that, depending on the situation or the shape or the smallness of the pores
which these parts of blood encounter, some of them go off to certain places
rather than to others, in the same way that anyone can see with various screens,
which, being pierced in different ways, serve to separate various grains from
one another.
Finally,
what is most remarkable in all this is the generation of animal spirits which
resemble a very slight wind or rather a very pure and lively flame which, by
climbing continually in great quantities from the heart into the brain, goes
from there through the nerves into the muscles and gives movement to all the
limbs, without it being necessary to imagine any other cause which has the
effect of making the most agitated and most penetrating parts of blood, those
most appropriate for making up these animal spirits, move towards the brain
rather than elsewhere, other than that the arteries which carry these parts of
the blood are those which come from the heart toward the brain by the most
direct route and that, following the laws of mechanics, which are the same as
nature's laws, when several things collectively tend to move towards the same
place where there is insufficient room for all of them, as the parts of blood
which leave the left cavity of the heart tend towards the brain, the most feeble
and less agitated parts must be turned away from the brain by the strongest
parts. In this way, only the latter parts reach the brain.
I
explained in particular detail all these things in the treatise which I had
planned to publish previously. And then I demonstrated what the nerves and
muscles in the human body were made of, so that the animal spirits, once inside
the nerves, would have the power to move its limbs, as one sees that heads, for
a little while after being cut off, continue to move and bite the earth, in
spite of the fact that they are no longer animated. I also showed what changes
must take places in the brain to cause the waking state, sleep, and dreams, how
light, sounds, smells, tastes, heat, and all the other qualities of external
objects could imprint various ideas on the brain through the mediation of the
senses, just as hunger, thirst, and the other inner passions can also send their
ideas to the brain; which of them must be taken there for common sense and where
these ideas are taken in, for memory which preserves them, and for fantasy which
can change them in various ways and compose new ones, and, in the same way,
distribute animal spirits to the muscles and make the limbs of the body move in
all the different ways—in relation to the objects which present themselves to
the senses and in relation to the interior physical passions—our bodies can
move themselves without being led by the will.
None
of this will seem strange to those who know how many varieties of automata, or
moving machines, human industry can make, by using only very few pieces in
comparison with the huge number of bones, muscles, nerves, arteries, veins, and
all the other parts in the body of each animal. They will look on this body as a
machine, which, having been made by the hand of God, is incomparably better
ordered and more inherently admirable in its movements than any of those which
human beings could have invented.
And here,
in particular, I stopped to reveal that if there were machines which had the
organs and the external shape of a monkey or of some other animal without
reason, we would have no way of recognizing that they were not exactly the same
nature as the animals; whereas, if there was a machine shaped like our bodies
which imitated our actions as much as is morally possible, we would always have
two very certain ways of recognizing that they were not, for all their
resemblance, true human beings.
The
first of these is that they would never be able to use words or other signs to
make words as we do to declare our thoughts to others. For one can easily
imagine a machine made in such a way that it expresses words, even that it
expresses some words relevant to some physical actions which bring about some
change in its organs (for example, if one touches it in some spot, the machine
asks what it is that one wants to say to it; if in another spot, it cries that
one has hurt it, and things like that), but one cannot imagine a machine that
arranges words in various ways to reply to the sense of everything said in its
presence, as the most stupid human beings are capable of doing.
The
second test is that, although these machines might do several things as well or
perhaps better than we do, they are inevitably lacking in some other, through
which we discover that they act, not by knowledge, but only by the arrangement
of their organs. For, whereas reason is a universal instrument which can serve
in all sorts of encounters, these organs need some particular arrangement for
each particular action. As a result of that, it is morally impossible that there
is in a machine's organs sufficient variety to act in all the events of our
lives in the same way that our reason empowers us to act.
Now,
by these two same means, one can also recognize the difference between human
beings and animals. For it is really remarkable that there are no men so dull
and stupid, including even idiots, who are not capable of putting together
different words and of creating out of them a conversation through which they
make their thoughts known; by contrast, there is no other animal, no matter how
perfect and how successful it might be, which can do anything like that. And
this inability does not come about from a lack of organs For we see that magpies
and parrots can emit words, as we can, but nonetheless cannot talk like us, that
is to say, giving evidence that they are thinking about what they are uttering;
whereas, men who are born deaf and dumb are deprived of organs which other
people use to speak—just as much as or more than the animals—but they have a
habit of inventing on their own some signs by which they can make themselves
understood to those who, being usually with them, have the spare time to learn
their language.
And
this point attests not merely to the fact that animals have less reason than
men, but also to the fact that they have none at all. For we see that it takes
very little for someone to learn how to speak, and since we observe inequality
among the animals of the same species just as much as among human beings, and
see that some are easier to train than others, it would be incredible that a
monkey or a parrot which is the most perfect of his species was not equivalent
in speaking to the most stupid child or at least a child with a troubled brain,
unless their soul had a nature totally different from our own. And one should
not confuse words with natural movements which attest to the passions and can be
imitated by machines as well as by animals, nor should one think, like some
ancients, that animals talk, although we do not understand their language. For
if that were true, because they have several organs related to our own, they
could just as easily make themselves understood to us as to the animals like
them.
Another
truly remarkable thing is that, although there are several animals which display
more industry in some of their actions than we do, we nonetheless see that they
do not display that at all in many other actions. Thus, the fact that they do
better than we do does not prove that they have a mind, for, if that were the
case, they would have more of it than any of us and would do better in all other
things; it rather shows that they have no reason at all, and that it's nature
which has activated them according to the arrangement of their organs—just as
one sees that a clock, which is composed only of wheels and springs, can keep
track of the hours and measure time more accurately than we can, for all our
care.
After
that, I described the reasonable soul and revealed that it cannot be inferred in
any way from the power of matter, like the other things I have spoken about, but
that it must be expressly created, and I described how it is not sufficient that
it is lodged in the human body like a pilot in his ship, perhaps simply to move
its limbs, but that it is necessary that the soul is joined and united more
closely with the body, so that it has, in addition, feelings and appetites
similar to ours and thus makes up a true human being.
As
for the rest, here I went on at some length on the subject of the soul, because
it is among the most important. For, apart from the error of those who deny God,
which I believe I have adequately refuted above, there is nothing which
distances feeble minds from the right road of virtue more readily than to
imagine that the soul of animals is the same nature as our own and that thus we
have nothing either to fear or to hope for after this life, any more than flies
and ants do; whereas, once one knows how different they are, one understands
much better the reasons which prove that the nature of our souls is totally
independent of the body, and thus it is not at all subject to dying along with
the body. Then, to the extent that one cannot see other causes which destroy the
soul, one is naturally led to judge that the soul is immortal.
Part
Six
It is now
three years since I reached the end of the treatise which contains all these
things and since I started to revise it in order to put it into the hands of a
printer. Then I learned that people to whom I defer and whose authority over my
actions could hardly be less than my own reason over my thoughts expressed
disapproval of an opinion about physics published a little earlier by someone
else*. I don't wish to say that I
subscribed to that opinion, but, although I had observed nothing before their
censure which I could imagine prejudicial to religion or the state, and thus
nothing which would have prevented me from writing if reason persuaded me, after
that I was nevertheless afraid that there might be something among my opinions
where I had gone astray, notwithstanding the great care I always took not to
accept new ideas into my beliefs for which I did not have very certain proofs
and not to write anything which would work to anyone's disadvantage. This was
sufficient to oblige me to alter my resolution to publish my opinions. For
although the reasons I had adopted earlier had been very strong, my inclination,
which has always led me to hate the profession of producing books, made me
immediately find enough other reasons to excuse myself in this matter. And,
given the nature of these reasons, on one side or the other, I'm quite
interested, not only in stating them here, but also in the possibility that the
public may learn something about them.
I
have never made a great deal of the things which come from my own mind, so while
I gathered no other fruits from the method I was using, other than that I
satisfied myself concerning some difficulties in the speculative sciences or
else that I tried to regulate my morals by reasons which my method taught me, I
did not think myself obliged to write anything. For where morals are concerned,
every person is so full of his own good sense that it would be possible to find
as many reformers as heads, if it was permitted to people (other than those God
has established as sovereigns over his people or those to whom he has given
sufficient grace and zeal to be prophets) to try changing anything in our
morality. Although my speculations pleased me a great deal, I thought that other
people had their own speculations which pleased them perhaps even more.
But
immediately after I had acquired some general notions concerning physics and, by
starting to test them on various particular difficulties, had noticed just where
they could lead and how much they differed from principles which people have
used up to the present time, I thought that I could not keep them hidden without
sinning greatly against the law which obliges us to promote as much as we can
the general good of all men. For my notions had made me see that it is possible
to reach understandings which are extremely useful for life, and that instead of
the speculative philosophy which is taught in the schools, we can find a
practical philosophy by which, through understanding the force and actions of
fire, air, stars, heavens, and all the other bodies which surround us as
distinctly as we understand the various crafts of our artisans, we
But
it was not only my desire for the invention of an infinite number of devices
which might enable us to enjoy without effort the fruits of the earth and all
the commodities found in it, but mainly also my desire for the preservation of
our health, which is, without doubt, the principal benefit and the foundation of
all the others in this life. For even the mind depends so much on the
temperament and the condition of the organs of the body that, if it is possible
to find some means to make human beings generally wiser and more skilful than
they have been up to this point, I believe we must seek that in medicine.
It is true that the medicine now practiced contains few things which are
remarkably useful. But without having any design to denigrate it, I am confident
that there is no one, not even those who make a living from medicine, who would
not claim that everything we know in medicine is almost nothing in comparison to
what remains to be known about it and that we could liberate ourselves from an
infinity of illnesses, both of the body and the mind, and also perhaps even of
the infirmities of ageing, if we had sufficient knowledge of their causes and of
all the remedies which nature has provided for us.
Now,
intending to spend all my life in research into such a necessary science and
having encountered a road which seemed to me such that one should infallibly
find this science, unless one was prevented either by the brevity of one's life
or by the lack of experiments, I judged that there was no better remedy against
these two obstacles than to communicate faithfully and completely to the public
the little I had found and to invite good minds to try to move on further, by
contributing, each according to his own inclination and power, to the
experiments which need to be conducted and by communicating to the public
everything they learn, so that the most recent people begin where the previous
ones have finished. If we thus joined the lives and labours of many people,
collectively we might go much further than each particular person could.
Besides, I notice that, where experiments are concerned, they are
increasingly necessary as one's knowledge advances, for at the beginning it is
better to conduct only those which present themselves to our sense and which we
cannot ignore, provided that we engage in a little reflection, than to seek out
more rare and original experiments, because these rarer ones are misleading,
when we do not yet know the causes of the more common phenomena, and the
circumstances on which they depend are almost always so particular and so
precise, that it is very difficult to observe them.
In
this work I kept to the following order: first, I tried to find the general
principles or the first causes of everything which exists or could exist in the
world, without taking into my account of this effect anything other than the
fact that God alone created it, not deducing anything additional, other than
certain grains of truth which are naturally in our souls. After that, I examined
what were the first and most common effects we could deduce from these causes.
By doing that, it seems to me, I found the heavens, the stars, and earth, and
even on the earth water, air, fire, minerals, and some other things, the sort
which are the most common of all and the simplest, and thus the easiest to know.
Then,
when I wanted to move down to more particular matters, so many varied ones
presented themselves to me that I did not think it would be possible for the
human mind to distinguish the forms or species of bodies on the earth from an
infinity of others which could exist there if the will of God had put them there
and, thus, that one could not adapt them to our use, unless one proceeded to the
causes through the effects and that one made use of several particular
experiments.
After
that, I turned my mind onto all the objects which had ever presented themselves
to my senses. I venture to say that I didn't notice in them anything which I
could not explain easily enough by the principles which I had found. But I must
also confess that the power of nature is so ample and vast and that its
principles are so simple and so general that I observed hardly any particular
effect which I did not immediately understand as being capable of being deduced
in several different ways, so that my greatest difficulty is usually to find on
which of these ways the effect depends. And to resolve this matter, I did not
know any other expedient than, once again, to look for some experiments which
would be such that their outcomes would not be the same if one of these ways had
to explain it rather than some other way.
As
for the rest, I am now at a point where I perceive well enough, it seems to me,
the method one has to use to make most of those experiments which can serve for
this purpose. But I also see that they are of such a kind and that there are so
many of them that neither my hands nor my income, even if I had a thousand times
more of both than I do, could suffice for all of them, so that my progress in
understanding nature will be proportional to the means I have for conducting
more or fewer experiments. This was what I promised myself I would make known in
the treatise which I wrote, as well as showing in it the practical value which
the public could gain from these experiments so clearly that I would oblige all
those who wished to promote the general well being of man, that is to say, all
those who are truly virtuous and who are not false (by pretending to virtue or
merely virtuous by public opinion), to communicate to me all the experiments
which they have already made, as well as to help me in researching those which
remain to be done.
But
since that time I had other reasons which made me change my mind and think that
I really must continue to write down all matters which I judged to have some
importance, to the extent that I discovered truth in them, and to bring to my
writing the same care that I would if I wanted it published, so that I would
have more time to examine such things well, since there is no doubt one always
looks more closely at what one thinks many people must see than at what one does
only for oneself, and often matters which seemed to me true when I began to
think of them appeared false when I wished to put them on paper. By writing
things down, I would not lose any opportunity to benefit the public, if I could,
and, if my writings are worth anything, those who have them after my death could
use them wherever they were most relevant. But I thought I must not, on any
account, agree that they be published during my life, so as to prevent the
hostility and controversies which they could perhaps arouse and the sort of
reputation which I could acquire from causing me to waste time which I planned
to use to instruct myself.
For
although it is true that each man is obliged to provide as much as is in him for
the good of others and that there is no value whatsoever in anything which has
no benefit for anyone, nevertheless it is also true that we should care about
things more distant than the present and that it is good to forget about things
which might bring some benefit to those now living when one's intention is to
create other things which will bring more benefits to our descendants. In fact,
I really wanted people to understand that the little I had learned up to this
point was almost nothing in comparison with what I was ignorant of and what I
did not despair of being able to learn. For it is almost the same with those who
discover truth little by little in the sciences as it is with those who, once
they start to become rich, have less trouble in making large acquisitions than
they did previously, when they were poorer, in making much smaller ones. Or,
again, one can compare them to leaders of armies whose forces usually grow in
proportion to their victories and who, in order to capture towns and provinces,
need more leadership to maintain their forces after the loss of a battle than
they do after winning one. For it is truly a matter of giving battle when one
tries to overcome all the difficulties and mistakes which prevent us from
reaching an understanding of the truth. And it is a battle loss when one accepts
some false opinion concerning any matter at all general and important.
Afterwards one requires a great deal more skill to put oneself in the same
condition one was in previously than one does to make great progress when one
already has confirmed principles.
In
my case, if I have previously found some truths in the sciences (and I hope that
the matters contained in this volume will make people conclude that I have found
some), I can say that those are only the consequences of and dependent upon five
or six major difficulties which I overcame and that I count these as battles in
which victory was on my side. Still, I am not afraid to state that I only need
to win two or three others like those in order to reach the final goal of my
project and that I am not so advanced in years. Thus, given the ordinary course
of nature, I still have enough leisure to bring my project to its conclusion.
But I think that I am all the more obliged to manage the time remaining to me,
now that I have more hope of being able to use it well, and I would, no doubt,
have many chances to lose that time, if I published the foundations of my
physics. For although these foundations are almost all so evident that one need
only hear them to believe them and there are none of them which, in my view, I
cannot prove, nevertheless, because it is impossible that they will agree with
all the various opinions of other men, I anticipate being often distracted by
the hostility they will give rise to.
One
could say that this opposition would be useful, to the extent it makes me
understand my mistakes, and that, if I have anything good, others will by this
means have a more complete understanding. Since several people can see more than
one man by himself, if people begin from now on making use of my principles,
they will also help me with their inventions. But even though I recognize that I
am very subject to error and that I almost never have faith in the first
thoughts which come to me, nevertheless the experience which I have of
objections which people could make about me prevents me from hoping for any
benefit from such objections. For I have already undergone the criticism of many
of those whom I held as friends and of some others who I thought considered me
indifferently and even of some in whom I knew malignity and envy would try hard
enough to uncover what affection concealed from my friends. But it rarely
happened that someone made an objection which I had not totally anticipated,
unless it was really distant from my subject, so that I have almost never met
any censor of my opinions who did not appear to me to be less rigorous or less
fair than myself. Moreover, I
have never observed that anyone has discovered any truth of which people were
ignorant before by means of the disputes practised in the schools. For when each
person tries to emerge victorious, people strive much harder to establish
probability than to weigh the reasons on one side or the other, and those who
have been good pleaders for a long time are not, on that account, better judges
afterwards.
As
for the practical use which other people derive from the communication of my
thoughts, it could not be all that great, since I have not taken them so far
that there is no need to add a great deal of things before they can be
practically applied. And I think I can say without vanity that if there is
anyone who can do that, the person should be me rather than someone else, not
because several minds incomparably better than mine could not be found in this
world, but because one cannot conceive of something so well and make it one's
own when one learns it from someone else as when one comes up with it oneself.
What's really true about this material is that, although I have often explained
some of my opinions to people with very good minds, who, while I was talking to
them, seemed to understand my opinions very clearly, nonetheless, when they have
repeated them, I have noticed that almost always they have changed them in such
a way that I would no longer admit them as mine.
Incidentally, I am more than happy to take this opportunity to beg our
descendants never to believe anything that people will tell them comes from me,
when I never divulged them myself, and I am not astonished at the extravagant
things which people attribute to those ancient philosophers whose writing we do
not possess. I don't judge that their thoughts were really irrational on that
account, seeing that they were the best minds of their times, but assume that
their thoughts have been misrepresented to us. For we see also that it almost
never happens that any of their disciples surpasses them, and I'm confident that
the most passionate of those people who follow Aristotle nowadays would consider
themselves fortunate if they could have as much knowledge of nature as he had,
even on condition that they would never know any more. They are like ivy which
tends not to climb higher than the trees which support it and which often even
comes down again when it has reached the tree tops. For it seems to me that
those people also come back down, that is, make themselves in some fashion less
knowledgeable than if they were to abandon their studying, when, not content
with knowing everything intelligibly explained by their author, they wish to
find, beyond that, the solution to several difficulties about which he has said
nothing and has perhaps never even thought.
However, their way of practising philosophy is extremely comfortable for
those who have nothing but really mediocre minds, for the obscurity of the
distinctions and the principles they use enables them to speak of everything as
boldly as they know how and to hold to everything that they state against the
most subtle and skilful minds, without their having the means to convince
anyone. In this it strikes me they are similar to a blind man who, in order to
fight on equal terms against someone who can see, makes him come into the bottom
of some really obscure cave. And I can state that such people have an interest
in my abstaining from publishing the principles of philosophy I used, because,
given that they are very simple and very evident, if I published them, I would
be doing roughly the equivalent of opening some windows and bringing the light
of day into this cave where they have gone down to fight each other.
But
even the best minds have no occasion to want to know these principles. For if
they want to know how to speak about everything and to acquire the reputation of
being scholarly, they will get there more easily in contenting themselves with
probability which can be found in all sorts of matters without great trouble,
rather than by seeking out the truth, which is not discovered except little by
little in some matters and which, when it is a question of speaking of other
matters, requires us to confess frankly that we are ignorant of them. If they
would rather have the undoubtedly preferable condition of knowing a few truths
over the vanity of appearing to be ignorant about nothing, and if they wish to
follow a plan similar to my own, for that they do not need me to say anything
more than I have already said in this discourse. For if they are capable of
moving on further than I have done, they will also, with all the more reason,
find for themselves everything I think I have found.
Since
I have never looked at anything except in an orderly way, it is certain that
what remains for me to discover is inherently more difficult and more hidden
than what I have been able to find, and they would have much less pleasure in
learning that from me than from themselves. Beyond that, the habit they will
acquire by searching first for easy things and then moving on gradually by
degrees to other more difficult things will serve them better than all my
instructions will be able to.
As
for me, I am convinced that if I had been taught from my youth all the truths
which I have found since my demonstrations and if I had had no trouble in
learning them, I would perhaps have never known any others. At the very least I
would never have acquired the habit and the skill which I think I have in
finding new truths to the extent that I apply myself in looking for them. In a
word, if there is in the world some work which cannot be properly completed by
anyone other than the same person who started it, it’s the work I do.
It's
true that so far the experiments which can help in that work are concerned, one
man by himself is not sufficient to undertake them all. But he cannot put to
practical use hands other than his own, except those of craftsmen or such people
as he can pay, who with the hope of profit, which is a very effective means,
will carry out everything exactly as he instructs them. As for volunteers who
from curiosity or a desire to learn perhaps offer to help him, apart from the
fact that ordinarily they promise more than they deliver and that they come up
with nothing but fine propositions, none of which ever succeeds, they inevitably
want to paid with the explanation of some difficulties or at least with
compliments and useless discussions which would cost him more time than he could
afford.
As
for the experiments which other people have carried out, even though they should
be willing enough to tell him about them, those who call such experiments
secrets will never do that. Such experiments for the most part contain so many
superfluous circumstances or ingredients that it would be very difficult for him
to decipher the truth of them. Beyond that, he would find almost all of them
badly explained or even false, because those who have carried them out have
forced themselves to make the experiment apparently conform to their principles,
so that if there were some experiments he could use, once again it would not be
worth the time he would have to take up to pick them out.
In
the same way, if there were in the world someone in whom people had great
confidence that he was capable of finding the greatest things and the most
useful for the public as possible, and if for this reason other men tried hard
to help him in every way to carry out his project with success, I don't see that
they could do anything for him other than to furnish the costs of the
experiments he needed to carry out, and, as to the rest, they could prevent his
leisure from being taken away by anyone's importunity. But beyond the fact that
I do not presume so much of myself as to wish to promise anything extraordinary
and that I do not indulge in thoughts so vain as to imagine to myself that the
pubic ought to show a great deal of interest in my plans, I do not have a soul
so base that I would be willing to accept from anyone a favour which people
might think I did not deserve.
All
these considerations combined were the reason, three years ago, that I did not
wish to publish the treatise which I had in my hands. I even made a
resolution that during my life I would not make public any other treatise which
was so general and from which one could learn the foundations of my physics.
But, once again, there have been two other reasons since then which have obliged
me to set down here some particular essays and to give the public some account
of my actions and my plans.
The
first is that if I failed to do this, several people who knew of the intention I
had previously of publishing some of my writing could imagine that the reasons
why I held back from doing so were more disadvantageous to me than they were.
For, although I do not like glory excessively, or, if I dare say it, although I
dislike it to the extent that I see it as contrary to peace and quiet, which I
value above everything, nonetheless I have also never tried to hide my actions
as if they were crimes, nor have I taken many precautions to remain unknown, as
much because I would have thought myself wrong if I did so, as because that
would have given me a sort of unease which would, once again, have been contrary
to the perfect peace of mind which I am looking for. Also, being always
indifferently poised between care to get known or not to get known, since I
could not prevent myself from acquiring some kind of reputation, I thought that
I ought to do my best at least to avoid having a bad one.
The other reason which obliged
me to write this is that I realized more and more every day how the plan I had
to teach myself was suffering a delay, because of an infinite number of
experiments I needed and because it is impossible that I carry them out without
the help of others. Although I do not flatter myself so much as to hope that the
public pays great attention to my interests, nonetheless by the same token I do
not want to let myself down so much so that I give an excuse for those who will
come after me to reproach me some day by saying that I could have done many
things much better than I did, if I had not so neglected making them understand
the ways in which they could contribute to my project.
And
I thought that it would be easy for me to chose some matters which, without
being subject to a great deal of controversy and without requiring me to state
more of my principles than I wanted to, would permit me to reveal with
sufficient clarity what I could or could not do in the sciences. In these
matters I cannot say if I have been successful, and I have no desire to ward off
anyone's criticism, as I talk in person about my own writings. But I will be
very pleased if people examine them. In order for people to have more chances to
do this, I request that all those who have some objections take the trouble to
send them to my publisher. If he tells me about them, I will try to attach my
response to their objection and publish them at the same time. In this way, the
readers, seeing the objections and my replies together, will judge the truth all
the more easily. For I promise never to make long replies but only to confess my
errors very candidly, if I recognize them, or else, if I cannot see them, to
state simply what I believe is required for the defence of what I have written,
without adding there an explanation of any new material, so that I don't get
endlessly involved with one matter after another.
If
some of those things which I have talked about at the beginning of the Dioptrics
and Meteors are shocking at first, because I call them suppositions and I
do not seem to have any desire to prove them, I urge people to have the patience
to read the whole text with attention, and I hope that they will be satisfied.
For it seems to me that the reasons follow in sequence in such a way that the
last ones are established by the first ones, which are their causes, and the
first ones are reciprocally established by the last ones which are their
effects. And people should not imagine that, in doing this, I am committing the
error which logicians call arguing in a circle. For since experimentation makes
most of these effects very certain, the causes which I have deduced do not serve
so much to prove these effects as to explain them, so the case is precisely
reversed: it is the causes which are proved by the effects.
And
I used the name suppositions for these causes so that people might know
what I think I can deduce from them about these first truths which I have
explained above. But I expressly wanted to avoid doing that, in order to prevent
certain minds who imagine that they understand in a single day everything that
another man has thought out in twenty years, as soon as he has said only two or
three words about these matters to them, and who are all the more subject to
error and less capable of truth, the more penetrating and bright they are, from
taking the opportunity to construct some extravagant philosophy on what they
believe are my principles, and in order to prevent people from attributing the
fault for that to me.
As
for the opinions which are entirely mine, I do not seek to excuse them as new.
To the extent that people think carefully about the reasons for them, I am
confident that they will find my opinions so simple and so consistent with
common sense that they will seem less extraordinary and less strange than some
others which people might have on the same subjects. And, in addition, I do not
boast that I am the first inventor of any of them, although I have never
accepted them merely because they were said by others or because they have not
been said by others, but simply because reason persuaded me to accept them.
If
craftsmen cannot immediately carry out the inventions explained in the Dioptrics,
I don't think that people can, for that reason, say that the text is a poor one.
For to the extent that dexterity and skill are required to make and to adjust
the machines which I have described, without missing the slightest detail, I
would be no less amazed if they were successful on the first attempt than if
someone could learn in a single day to play the lute extremely well, simply
because someone had given him a good musical score.
If
I write in French, the language of my country, rather than in Latin, the
language of my teachers, the reason is that I hope those who use only their
natural reason, pure and simple, will judge my opinions better that those who
believe nothing but ancient books. And as for those who combine good sense with
study, who are the only ones I hope to have as my judges, I am confident that
they will not be so partial to Latin that they will refuse to listen to my
reasons because I explain them in the common language.
As
for the rest, I do not wish to talk here in particular detail about the future
progress which I hope to make in the sciences, nor to commit myself to promising
the public what I am not confident of achieving. But I will only say that I have
resolved not to use the time remaining to me for anything other than trying to
acquire some knowledge of nature of such a kind that people can derive from it
rules for medicine more reliable that those which they have at present, that my
inclination keeps me so far away from all kinds of other projects, mainly those
which can be practically useful to some people only by harming others, and that
if some circumstance forced me to use my time in this way, I don't think I would
be capable of succeeding.
In
these matters I am making a declaration here which I well understand cannot make
me important in the world, but also I have no desire to be important. I will
always hold myself more obliged to those by whose favour I enjoy my leisure
unencumbered than to those who might offer me the most prestigious positions on
earth.
*Lully:
Ramon Llull, a thirteenth-century philosopher who wrote a rational defence of
Christianity.
*this volume: in the same book as this Discourse, Descartes included sections on optics, geometry, and meteorology. [Back to Text]
*chimera: a mythological Greek monster. [Back to Text]
*vena arteriosa: arterial vein. [Back to Text]
*The English doctor is William Harvey who published his pioneering work on the heart and circulation of the blood in 1628. [Back to Text]
*somebody
else: a reference to Galileo, whose publication in defence of Copernicus’
sun centered model of the solar system (in 1632) got him into serious
difficulties with the church. [Back to Text]
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