3. l
Philosophy: The Big Questions
Series Editor: James P. Sterba, University ofNotre Dame, Indiana
Designed to elicit a philosophical response in the mind of the student, this distinctive
series of anthologies provides essential classical and contemporary readings that serve to
make the central questions ofphilosophy come alive for today's students. It presents
complete coverage ofthe Anglo-American tradition ofphilosophy, as well as the kinds of
questions and challenges that it confronts today, both from other cultural traditions and
from theoretical movements such as feminism and postmodernism.
Aesthetics: the Big Questions
Edited by Carolyn Korsmeyer
Epistemology: the Big Questions
Edited by Linda Martin AlcotT
Ethics: the Big Questions
Edited by James P. Sterba
Metaphysics: the Big Qpestions
Edited by Peter van Inwagen and Dean W. Zimmerman
Philosophy ofLanguage: the Big Questions
Edited by Andrea Nye
Philosophy ofReligion: the Big Qpestions
Edited by Eleonore Stump and Michael J. Murray
Race, Class, Gender, and Sexuality: the Big Questions
Edited by Naomi Zack, Laurie Shrage, and Crispin Sartwell
6. Preface
Acknowledgments
CONTENTS
PART ONE WHAT IS KNOWLEDGE?
Introduction
l Meditations
RENE DESCARTES
2 On Certainty
LUDWIG WITTGENSTEIN
3 The Right to Be Sure
A. J. AYER
4 Epistemology's End
CATHERINE z. ELGIN
PART TWO HOW ARE BELIEFS JUSTIFIED?
Introduction
5 Internalism and Externalism in Epistemology
WILLIAM P. ALsTON
6 The General Conditions of Knowledge: Justification
CARL GINET
7 What is Justified Belief?
ALVIN GoLDMAN
8 Contextualism and Knowledge Attributions
KEITH DEROSE
9 Taking Subjectivity into Account
LoRRAINE CoDE
l 0 The Practices of Justification
ALESSANDRA TANESINI
viii
XI
l
3
5
14
20
26
41
43
45
79
89
109
124
152
v
7. CONTENTS
PART THREE WHAT IS THE STRUCTURE OF KNOWLEDGE?
Introduction
11 The Myth of the Given
RoDERICK CHISHOLM
12 The Raft and the Pyramid
ERNEST SosA
13 The Elements of Coherentism
LAURENCE BoNJouR
14 The Hermeneutic Circle
HANS-GEORG GADAMER
PART FOUR WHAT IS NATURALIZED EPISTEMOLOGY?
Introduction
15 Epistemology Naturalized
W. V. 0. QUINE
16 What is "Naturalized Epistemology"?
JAEGWON KIM
17 Putting Naturalized Epistemology to Work
PHYLLIS RooNEY
PART FIVE WHAT IS TRUTH?
Introduction
18 The Minimal Theory
PAUL HoRWICH
19 Language, Truth and Reason
IAN HACKING
20 Pragmatism, Relativism, and Irrationalism
RicHARD RoRTY
PART SIX WHAT IF WE DON'T KNOW ANYTHING AT ALL?
Introduction
21 Cartesian Skepticism and Inference to the Best Explanation
JoNATHAN VoGEL
22 Skepticism and the Possibility of Knowledge
BARRY STROUD
23 Othello's Doubt/Desdemona's Death: The Engendering of
Scepticism
NAOMI SCHEMAN
PART SEVEN HOW IS EPISTEMOLOGY POLITICAL?
Introduction
24 The "Maleness" ofReason
GENEVIEVE LLOYD
vi
165
167
169
187
210
232
249
251
253
265
285
307
309
311
322
336
349
351
352
360
365
383
385
387
9. PREFACE
Epistemology is a philosophical inquiry into the nature of knowledge, what
justifies a belief, and what we mean when we say that a claim is true. As such,
epistemology may seem daunting, but actually epistemological questions face
us everyday. Ifi read something in the newspaper and believe what I have read,
can I then be said to "know" it? Am I justified in believing what a teacher tells
me, or what I remember ofa past event, or only that which I can "see with my
own eyes"? Is the most recently accepted scientific theory "true," even though
it is likely to be modified or rejected in the future? Ifwe cannot rely on science
for the truth, how do we know we know anything at all?
Epistemology in the context ofwestern philosophy is often thought to have
begun with Plato, especially in the Theaetetus, where knowledge is first formu-
lated as justified true belief; but as a self-conscious area of inquiry and as a
coherent, developing conversation, it is usually dated from Rene Descartes'
Meditations, a section ofwhich opens this volume. Descartes initiated a radical
challenge to tradition, and thus was a major influence on later Enlightenment
philosophers, by calling all of his beliefs into doubt. Taking their lead from
Descartes, many epistemologists since have been preoccupied with refuting
skepticism and establishing both the possibility as well as the limits of human
knowledge. For the last hundred years or so, however, epistemologists have
shifted away from such ambitions toward more delimited questions, particu-
larly those concerned with problems of justification, the organizational struc-
ture of knowledge, the meanings of epistemic terms, and the psychology of
belief formation.
The twentieth-century linguistic turn, which translated traditional philosophi-
cal problems into questions about language, had a significant impact on episte-
mology as well as other fields, suggesting that the problem ofknowledge was at
bottom a problem concerning how to use the verb "to know" correctly, and
that a close analysis of linguistic practice could answer most if not all of our
epistemological questions. Perhaps most dramatic was the impact on accounts
oftruth, which came to be widely understood as a sort ofexclamation point on
a sentence without substantive meaning. Alternative to the focus on language
was a focus on psychology and the scientific study of cognition, instigated by
viii
10. PREFACE
W. V. 0. Quine's argument that epistemology could find its answers by simply
studying how believers actually justifY their beliefs. This development, known
today as the naturalized approach to epistemology, is also included in this vol-
ume.
These two twentieth-century trends in epistemology - the trend toward lin-
guistic analysis and the trend toward a naturalistic approach - drove a broad
wedge between the conversations about knowledge that were occurring mostly
among Anglo-American philosophers and those occurring mostly among other
European philosophers. Within the latter conversation, represented in this vol-
ume by Hans-Georg Gadamer, Ian Hacking, and Mary and Jim Tiles, the prob-
lem of history looms large for knowledge. That is, ifour processes ofknowing
(or, as Hacking puts it, "styles of reasoning") evolve historically, and ifwe as
knowers are historically conditioned by the available modes of perception and
self-reflection present in our cultural era, then how can we rely on even our best
methods as routes to truth? Actually, such a skeptical conclusion as this rhetori-
cal question might seem to invite is not the general European (or "continen-
tal") response to the problem ofhistory in relation to knowledge, but rather a
reconfigured metaphysical account ofwhat our claims to truth in reality entail.
The differences between Anglo-American and continental approaches to phi-
losophy sometimes divert attention from the significant differences that exist
within Anglo-American philosophy itself. The centrality of the problem of
skepticism to epistemology is a case in point. Some have thought that episte-
mology is fundamentally or at least unavoidably concerned with skepticism.
David Hume believed, for example, that sustained reflection about knowledge
will eventually generate a skeptical attitude toward any claims to certainty. This
reminds us ofthe adage about Socrates, that he knew enough to know that he
didn't really know much at all. IfHume is correct, and epistemology is under-
stood to be a sustained reflection about knowledge, then the need to consider
and refute skepticism would seem to be its necessary core project. One result of
this approach is that some proposed theories ofknowledge, such as coherentism,
will be rejected on the grounds that they cannot supply such a refutation.
Coherentists hold that beliefs are justified on the basis oftheir ability to cohere
with our web of beliefs, but what if the whole web is itself false? Unless
coherentism can justifY the web of beliefs as a whole, the coherentist procedure
does not guarantee epistemic justification at all.
However, not all Anglo-American epistemologists agree about the centrality
of skepticism in this way. Some hold that we know that we know at least some
things, and the best way to ascertain the features of knowledge is then to ex-
plore what it is about the knowledge we do have that makes it knowledge.
Going more on the offensive, others have argued that the concept ofskepticism
does not make sense, that it is incoherent in itself or self-refuting, since it re-
quires some beliefs to generate a skeptical doubt in the first place, or because
the skeptic is forced into a performative contradiction between the doxastic
requirements ofeveryday life ("there is a truck barreling towards me") and their
putative philosophical commitments. More recently, in this century, some have
argued that the project to refute skepticism presupposes the possibility ofchar-
ix
11. acterizing all ofour beliefs in one totalizing heap, ofstanding back from them
as it were and assessing their status as a group. Thus, if sustained reflection on
knowledge leads one to entertain general skeptical doubts, perhaps we should
reflect, as Wittgenstein suggests, on how we are going about the process of
reflection itself, and with what questions, concepts, and methodological com-
mitments we begin.
For this volume, essays are collected from a wide range ofphilosophical start-
ing points in order to generate a more comprehensive exploration ofepistemo-
logical problems. My eye has been toward the future, and for that reason I have
not included essays dealing with the Gettier problem, a chapter ofepistemology
that looks (thankfully) to be closing. It is my hope that in the future, twentieth-
century impediments to conversations across diverse approaches in epistemol-
ogy can be overcome. The fruitful results ofthis new dialogue will likely invigorate
the field and resolve some stalemated debates. My graduate students at Syracuse
University, to whom I dedicate this book, have inspired me to think creatively
and optimistically about the future of philosophy. I would like especially to
thank Heather Battaly, Marc Hight, and Eric Ramirez-Weaver for their invalu-
able editorial assistance. I am also very grateful to William Alston and Nancy
Tuana for their helpful advice.
X
14. ACKNOWLEDGMENTS
ism, and Irrationalism" in Proceedings and Addresses, Vol. 50, No.6, pp. 719-
38, reprinted by kind permission of the American Philosophical Association
and the author;
TheJournal ofPhilosophy: for Jonathan Vogel, "Cartesian Skepticism and Infer-
ence to the Best Explanation" in TheJournal ofPhilosophy, LXXXVII, 11, (No-
vember 1990), pp. 658-66, reprinted by kind permission ofthe publishers and
the author;
The Journal ofPhilosophy: for Barry Stroud, "Skepticism and the Possibility of
Knowledge" in TheJournal ofPhilosophy, LXXXI, 11, (October 1984), pp. 545-
51, reprinted by kind permission of the publishers;
Academic Printing and Publishing: for Naomi Scheman, "Othello's Doubt/
Desdemona's Death: The Engendering of Scepticism," pp. 57-74 in Power,
Gender, Values, edited by Judith Genova (Edmonton, AB: Academic Printin'g
and Publishing, 1987). Reprinted by kind permission ofAcademic Printing and
Publishing;
University of Minnesota Press: for Genevieve Lloyd, "The 'Maleness' of Rea-
son," pp. 103-10 and p. 122 in The Man ofReason: ccMale'' and ccFemale" in
Western Philosophy (Minneapolis: University of Minnesota Press, 1984). Re-
printed by kind permission of the University of Minnesota Press;
Social Theory and Practice: for Charles W. Mills, "Alternative Epistemologies"
in Social Theory and Practice, Vol. 14, No. 3, (Fall 1988), pp. 237-63, re-
printed by kind permission of the publisher and the author;
Every effort has been made to trace the copyright holders but if any have been
inadvertently overlooked the publishers will be pleased to make the necessary
arrangements at the first opportunity. The publishers apologize for any errors
or omissions in the above list and would be grateful to be notified ofany correc-
tions that should be incorporated in the next edition or reprint of this book.
xiii
15. PART ONE
WHAT IS KNOWLEDGE?
Introduction
l Meditations
RENE DESCARTES
2 On Certainty
LuDWIG WITTGENSTEIN
3 The Right to Be Sure
A. J. AYER
4 Epistemology's End
CATHERINE Z. ELGIN
16. Introduction
Rene Descartes (1596-1650) was a French philosopher, mathematician, and
scientist who, although writing well before the Enlightenment, had the cour-
age and audacity to challenge the validity ofall his beliefs, including his beliefin
God. Ironically, in pursuing the farthest reaches of what can be doubted,
Descartes found the basis ofknowledge itself. Descartes' meditations upon which
ofhis b~liefs might survive the test of rational doubt created a legacy that em-
phasized the need to justifY our beliefs through tests ofreason, logic, and clar-
ity. Thus, for Descartes, only those beliefs which have survived the rigor ofsuch
tests can be called knowledge.
The two essays following the section taken from Descartes' Meditations offer
representative twentieth-century approaches to knowledge through considera-
tions of how and when we use the verb "to know." A. J. Ayer (1910-89) un-
derstands the question ofknowledge as a question ofmeaning, since knowledge
must be expressed in meaningful sentences before its status can be evaluated.
Ayer then uses the norms ofeveryday language to flesh out and ultimately sup-
port the classical definition ofknowledge as justified true belief. One's "right to
be sure," or to be confident in making knowledge claims, can best be elucidated
through an account of the rules oflanguage.
Ludwig Wittgenstein (1889-1951), writing before Ayer, was actually the in-
stigator behind this linguistic approach to philosophical problems. However, in
this excerpt from his late work, On Certainty, Wittgenstein suggests some rather
different conclusions to Ayer. It is not so much that philosophical problems can
be solved through a turn toward linguistic practice, but that they can thereby be
revealed as specious. He suggests we ask, when does doubt arise in the course of
everyday knowledge, and when does it not arise. Wittgenstein seems to be mis-
chievously suggesting that sustained philosophical reflections have only con-
fused our understanding ofwhat is necessary in order to have the "right to be
sure."
Catherine Elgin's essay elegantly distinguishes between three types ofepiste-
mological approach, thus introducing the range ofcontemporary positions run-
ning from forms offoundationalism and positivism on the one hand all the way
toward forms ofidealism and postmodernism on the other. She organizes this
range ofoptions into three general conceptions ofwhat knowledge is, and con-
trasts these with regard to their real-world applicability and whether they avoid
relativism or skepticism. Taking issue with Ayer and Wittgenstein, Elgin argues
that our choice between these approaches will be largely based on, not just
linguistic rules, but our metaphysical intuitions and accounts of the real.
What, then, is knowledge? Perhaps this term itself admits of more than one
valid definition, depending on what project one is engaged in. Below is a range
ofsuch projects.
Further Reading
Cottingham, John. Descartes. Oxford: Basil Blackwell, 1986.
17. INTRODUCTION
Dancy, Jonathan. An Introduction to Contemporary Epistemology. Oxford: Basil Blackwell,
1985.
Hacker, P. M. S. Insight and Illusion: Themes in the Philosophy of Wittgenstein. Revised
edition. Oxford: Clarendon Press, 1986.
Russell, Bertrand. The Problems ofPhilosophy. Oxford: Oxford University Press, 1912.
4
18. I Meditations
Rene Descartes
MEDITATIONS ON FIRST PHILOSOPHY
in which are demonstrated the existence of God and the distinction between
the human soul and the body
First Meditation
What can be called into doubt
Some years ago I was struck by the large number of falsehoods that I had ac-
cepted as true in my childhood, and by the highly doubtful nature ofthe whole
edifice that I had subsequently based on them. I realized that it was necessary,
once in the course ofmy life, to demolish everything completely and start again
right from the foundations ifl wanted to establish anything at all in the sciences
that was stable and likely to last. But the task looked an enormous one, and I
began to wait until I should reach a mature enough age to ensure that no
subsequent time oflife would be more suitable for tackling such inquiries. This
led me to put the project off for so long that I would now be to blame if by
pondering over it any further I wasted the time still left for carrying it out. So
today I have expressly rid my mind ofall worries and arranged for myselfa clear
stretch of free time. I am here quite alone, and at last I will devote myself
sincerely and without reservation to the general demolition ofmy opinions.
But to accomplish this, it will not be necessary for me to show that all my
opinions are false, which is something I could perhaps never manage. Reason
now leads me to think that I should hold back my assent from opinions which
are not completely certain and indubitable just as carefully as I do from those
which are patently false. So, for the purpose ofrejecting all my opinions, it will
be enough if I find in each of them at least some reason for doubt. And to do
this I will not need to run through them all individually, which would be an
endless task. Once the foundations of a building are undermined, anything
built on them collapses of its own accord; so I will go straight for the basic
principles on which all my former beliefs rested.
Whatever I have up till now accepted as most true I have acquired either from
the senses or through the senses. But from time to time I have found that the
senses deceive, and it is prudent never to trust completely those who have de-
ceived us even once.
Yet although the senses occasionally deceive us with respect to objects which
are very small or in the distance, there are many other beliefs about which doubt
5
19. RENE DESCARTES
is quite impossible, even though they are derived from the senses- for example,
that I am here, sitting by the fire, wearing a winter dressing-gown, holding this
piece ofpaper in my hands, and so on. Again, how could it be denied that these
hands or this whole body are mine? Unless perhaps I were to liken myself to
madmen, whose brains are so damaged by the persistent vapours ofmelancholia
that they firmly maintain they are kings when they are paupers, or say they are
dressed in purple when they are naked, or that their heads are made ofearthen-
ware, or that they are pumpkins, or made of glass. But such people are insane,
and I would be thought equally mad if I took anything from them as a model
for myself.
A brilliant piece ofreasoning! As ifI were not a man who sleeps at night, and
regularly has all the same experiences1
while asleep as madmen do when awake
- indeed sometimes even more improbable ones. How often, asleep at night,
am I convinced of just such familiar events - that I am here in my dressing-
gown, sitting by the fire- when in fact I am lying undressed in bed! Yet at the
moment my eyes are certainly wide awake when I look at this piece of paper; I
shake my head and it is not asleep; as I stretch out and feel my hand I do so
deliberately, and I know what I am doing. All this would not happen with such
distinctness to someone asleep. Indeed! As if I did not remember other occa-
sions when I have been tricked by exactly similar thoughts while asleep! As I
think about this more carefully, I see plainly that there are never any sure signs
by means of which being awake can be distinguished from being asleep. The
result is that I begin to feel dazed, and this very feeling only reinforces the
notion that I may be asleep.
Suppose then that I am dreaming, and that these particulars - that my eyes
are open, that I am moving my head and stretching out my hands - are not
true. Perhaps, indeed, I do not even have such hands or such a body at all.
Nonetheless, it must surely be admitted that the visions which come in sleep are
like paintings, which must have been fashioned in the likeness ofthings that are
real, and hence that at least these general kinds ofthings - eyes, head, hands and
the body as a whole - are things which are not imaginary but are real and exist.
For even when painters try to create sirens and satyrs with the most extraordi-
nary bodies, they cannot give them natures which are new in all respects; they
simply jumble up the limbs of different animals. Or if perhaps they manage to
think up something so new that nothing remotely similar has ever been seen
before - something which is therefore completely fictitious and unreal- at least
the colours used in the composition must be real. By similar reasoning, al-
though these general kinds ofthings - eyes, head, hands and so on - could be
imaginary, it must at least be admitted that certain other even simpler and more
universal things are real. These are as it were the real colours from which we
form all the images ofthings, whether true or false, that occur in our thought.
This class appears to include corporeal nature in general, and its extension;
the shape ofextended things; the quantity, or size and number ofthese things;
the place in which they may exist, the time through which they may endure,2
and so on.
So a reasonable conclusion from this might be that physics, astronomy, medi-
6
20. MEDITATIONS
cine, and all other disciplines which depend on the study of composite things,
are doubtful; while arithmetic, geometry and other subjects ofthis kind, which
deal only with the simplest and most general things, regardless ofwhether they
really exist in nature or not, contain something certain and indubitable. For
whether I am awake or asleep, two and three added together are five, and a
square has no more than four sides. It seems impossible that such transparent
truths should incur any suspicion of being false.
And yet firmly rooted in my mind is the long-standing opinion that there is
an omnipotent God who made me the kind of creature that I am. How do I
know that he has not brought it about that there is no earth, no sky, no ex-
tended thing, no shape, no size, no place, while at the same time ensuring that
all these things appear to me to exist just as they do now? What is more, since I
sometimes believe that others go astray in cases where they think they have the
most perfect knowledge, may I not similarly go wrong every time I add two and
three or count the sides of a square, or in some even simpler matter, if that is
imaginable? But perhaps God would not have allowed me to be deceived in this
way, since he is said to be supremely good. But if it were inconsistent with his
goodness to have created me such that I am deceived all the time, it would seem
equally foreign to his goodness to allow me to be deceived even occasionally;
yet this last assertion cannot be made.3
Perhaps there may be some who would prefer to deny the existence of so
powerful a God rather than believe that everything else is uncertain. Let us not
argue with them, but grant them that everything said about God is a fiction.
According to their supposition, then, I have arrived at my present state by fate
or chance or a continuous chain of events, or by some other means; yet since
deception and error seem to be imperfections, the less powerful they make my
original cause, the more likely it is that I am so imperfect as to be deceived all
the time. I have no answer to these arguments, but am finally compelled to
admit that there is not one of my former beliefs about which a doubt may not
properly be raised; and this is not a flippant or ill-considered conclusion, but is
based on powerful and well thought-out reasons. So in future I must withhold
my assent from these former beliefs just as carefully as I would from obvious
falsehoods, if I want to discover any certainty.4
But it is not enough merely to have noticed this; I must make an effort to
remember it. My habitual opinions keep coming back, and, despite my wishes,
they capture my belief, which is as it were bound over to them as a result oflong
occupation and the law of custom. I shall never get out of the habit of confi-
dently assenting to these opinions, so long as I suppose them to be what in fact
they are, namely highly probable opinions - opinions which, despite the fact
that they are in a sense doubtful, as has just been shown, it is still much more
reasonable to believe than to deny. In view ofthis, I think it will be a good plan
to turn my will in completely the opposite direction and deceive myself, by
pretending for a time that these former opinions are utterly false and imaginary.
I shall do this until the weight ofpreconceived opinion is counter-balanced and
the distorting influence of habit no longer prevents my judgement from per-
ceiving things correctly. In the meantime, I know that no danger or error will
7
21. RENE DESCARTES
result from my plan, and that I cannot possibly go too far in my distrustful
attitude. This is because the task now in hand does not involve action but merely
the acquisition ofknowledge.
I will suppose therefore that not God, who is supremely good and the source
oftruth, but rather some malicious demon ofthe utmost power and cunning has
employed all his energies in order to deceive me. I shall think that the sky, the
air, the earth, colours, shapes, sounds and all external things are merely the delu-
sions ofdreams which he has devised to ensnare my judgement. I shall consider
myself as not having hands or eyes, or flesh, or blood or senses, but as falsely
believing that I have all these things. I shall stubbornly and firmly persist in this
meditation; and, even ifit is not in my power to know any truth, I shall at least
do what is in my power,5
that is, resolutely guard against assenting to any false-
hoods, so that the deceiver, however powerful and cunning he may be, will be
unable to impose on me in the slightest degree. But this is an arduous undertak-
ing, and a kind oflaziness brings me back to normal life. I am like a prisoner who
is enjoying an imaginary freedom while asleep; as he begins to suspect that he is
asleep, he dreads being woken up, and goes along with the pleasant illusion as
long as he can. In the same way, I happily slide back into my old opinions and
dread being shaken out ofthem, for fear that my peaceful sleep may be followed
by hard labour when I wake, and that I shall have to toil not in the light, but
amid the inextricable darkness ofthe problems I have now raised.
Second Meditation
The nature ofthe human mind, and how it is better known than the
body
So serious are the doubts into which I have been thrown as a result ofyester-
day's meditation that I can neither put them out ofmy mind nor see any way of
resolving them. It feels as if I have fallen unexpectedly into a deep whirlpool
which tumbles me around so that I can neither stand on the bottom nor swim
up to the top. Nevertheless I will make an effort and once more attempt the
same path which I started on yesterday. Anything which admits ofthe slightest
doubt I will set aside just as if I had found it to be wholly false; and I will
proceed in this way until I recognize something certain, or, ifnothing else, until
I at least recognize for certain that there is no certainty. Archimedes used to
demand just one firm and immovable point in order to shift the entire earth; so
I too can hope for great things if I manage to find just one thing, however
slight, that is certain and unshakeable.
I will suppose then, that everything I see is spurious. I will believe that my
memory tells me lies, and that none ofthe things that it reports ever happened.
I have no senses. Body, shape, extension, movement and place are chimeras. So
what remains true? Perhaps just the one fact that nothing is certain.
Yet apart from everything I have just listed, how do I know that there is not
something else which does not allow even the slightest occasion for doubt? Is
8
22. MEDITATIONS
there not a God, or whatever I may call him, who puts into rne6
the thoughts I
am now having? But why do I think this, since I myself may perhaps be the
author ofthese thoughts? In that case am not I, at least, something? But I have
just said that I have no senses and no body. This is the sticking point: what
follows from this? Am I not so bound up with a body and with senses that I
cannot exist without them? But I have convinced myselfthat there is absolutely
nothing in the world, no sky, no earth, no minds, no bodies. Does it now
follow that I too do not exist? No: ifl convinced myself of something7
then I
certainly existed. But there is a deceiver ofsupreme power and cunning who is
deliberately and constandy deceiving me. In that case I too undoubtedly exist,
if he is deceiving me; and let him deceive me as much as he can, he will never
bring it about that I am nothing so long as I think that I am something. So after
considering everything very thoroughly, I must finally conclude that this propo-
sition, I am, I exist, is necessarily true whenever it is put forward by me or
conceived in my mind.
But I do not yet have a sufficient understanding ofwhat this "I" is, that now
necessarily exists. So I must be on my guard against carelessly taking something
else to be this "1", and so making a mistake in the very item ofknowledge that
I maintain is the most certain and evident of all. I will therefore go back and
meditate on what I originally believed myself to be, before I embarked on this
present train of thought. I will then subtract anything capable of being weak-
ened, even minimally, by the arguments now introduced, so that what is left at
the end may be exacdy and only what is certain and unshakeable.
What then did I formerly think I was? A man. But what is a man? Shall I say
"a rational animal"? No; for then I should have to inquire what an animal is,
what rationality is, and in this way one question would lead me down the slope
to other harder ones, and I do not now have the time to waste on subdeties of
this kind. Instead I propose to concentrate on what carne into my thoughts
spontaneously and quite naturally whenever I used to consider what I was.
Well, the first thought to come to mind was that I had a face, hands, arms and
the whole mechanical structure of limbs which can be seen in a corpse, and
which I called the body. The next thought was that I was nourished, that I
moved about, and that I engaged in sense-perception and thinking; and these
actions I attributed to the soul. But as to the nature ofthis soul, either I did not
think about this or else I imagined it to be something tenuous, like a wind or
fire or ether, which permeated my more solid parts. As to the body, however, I
had no doubts about it, but thought I knew its nature distincdy. Ifl had tried
to describe the mental conception I had of it, I would have expressed it as
follows: by a body I understand whatever has a determinable shape and a defin-
able location and can occupy a space in such a way as to exclude any other body;
it can be perceived by touch, sight, hearing, taste or smell, and can be moved in
various ways, not by itselfbut by whatever else comes into contact with it. For,
according to my judgement, the power of self-movement, like the power of
sensation or of thought, was quite foreign to the nature of a body; indeed, it
was a source ofwonder to me that certain bodies were found to contain facul-
ties ofthis kind.
9
23. RENE DESCARTES
But what shall I now say that I am, when I am supposing that there is some
supremely powerful and, ifit is permissible to say so, malicious deceiver, who is
deliberately trying to trick me in every way he can? Can I now assert that I
possess even the most insignificant of all the attributes which I have just said
belong to the nature of a body? I scrutinize them, think about them, go over
them again, but nothing suggests itself; it is tiresome and pointless to go through
the list once more. But what about the attributes I assigned to the soul? Nutri-
tion or movement? Since now I do not have a body, these are mere fabrications.
Sense-perception? This surely does not occur without a body, and besides, when
asleep I have appeared to perceive through the senses many things which I
afterwards realized I did not perceive through the senses at all. Thinking? At last
I have discovered it - thought; this alone is inseparable from me. I am, I exist-
that is certain. But for how long? For as long as I am thinking. For it could be
that were I totally to cease from thinking, I should totally cease to exist. At
present I am not admitting anything except what is necessarily true. I am, then,
in the strict sense only a thing that thinks;8
that is, I am a mind, or intelligence,
or intellect, or reason - words whose meaning I have been ignorant of until
now. But for all that I am a thing which is real and which truly exists. But what
kind of a thing? As I have just said - a thinking thing.
What else am I? I will use my imagination.9
I am not that structure oflimbs
which is called a human body. I am not even some thin vapour which permeates
the limbs- a wind, fire, air, breath, or whatever I depict in my imagination; for
these are things which I have supposed to be nothing. Let this supposition
stand,10
for all that I am still something. And yet may it not perhaps be the case
that these very things which I am supposing to be nothing, because they are
unknown to me, are in reality identical with the "I" ofwhich I am aware? I do
not know, and for the moment I shall not argue the point, since I can make
judgements only about things which are known to me. I know that I exist; the
question is, what is this "I" that I know? Ifthe "I" is understood strictly as we
have been taking it, then it is quite certain that knowledge ofit does not depend
on things ofwhose existence I am as yet unaware; so it cannot depend on any of
the things which I invent in my imagination. And this very word "invent" shows
me my mistake. It would indeed be a case of fictitious invention if I used my
imagination to establish that I was something or other; for imagining is simply
contemplating the shape or image of a corporeal thing. Yet now I know for
certain both that I exist and at the same time that all such images and, in gen-
eral, everything relating to the nature of body, could be mere dreams [and
chimeras]. Once this point has been grasped, to say "I will use my imagination
to get to know more distinctly what I am" would seem to be as silly as saying "I
am now awake, and see some truth; but since my vision is not yet clear enough,
I will deliberately fall asleep so that my dreams may provide a truer and clearer
representation." I thus realize that none of the things that the imagination
enables me to grasp is at all relevant to this knowledge of myself which I pos-
sess, and that the mind must therefore be most carefully diverted from such
things11
ifit is to perceive its own nature as distinctly as possible.
But what then am I? A thing that thinks. What is that? A thing that doubts,
10
24. MEDITATIONS
understands, affirms, denies, is willing, is unwilling, and also imagines and has
sensory perceptions.
This is a considerable list, ifeverything on it belongs to me. But does it? Is it
not one and the same "I" who is now doubting almost everything, who none-
theless understands some things, who affirms that this one thing is true, denies
everything else, desires to know more, is unwilling to be deceived, imagines
many things even involuntarily, and is aware of many things which apparently
come from the senses? Are not all these things just as true as the fact that I exist,
even if! am asleep all the time, and even ifhe who created me is doing all he can
to deceive me? Which ofall these activities is distinct from my thinking? Which
of them can be said to be separate from myself? The fact that it is I who am
doubting and understanding and willing is so evident that I see no way ofmak-
ing it any clearer. But it is also the case that the "I" who imagines is the same
"I". For even if, as I have supposed, none ofthe objects ofimagination are real,
the power of imagination is something which really exists and is part of my
thinking. Lastly, it is also the same "I" who has sensory perceptions, or is aware
of bodily things as it were through the senses. For example, I am now seeing
light, hearing a noise, feeling heat. But I am asleep, so all this is false. Yet I
certainly seem to see, to hear, and to be warmed. This cannot be false; what is
called "having a sensory perception" is strictly just this, and in this restricted
sense of the term it is simply thinking.
From all this I am beginning to have a rather better understanding ofwhat I
am. But it still appears - and I cannot stop thinking this- that the corporeal
things ofwhich images are formed in my thought, and which the senses inves-
tigate, are known with much more distinctness than this puzzling "I" which
cannot be pictured in the imagination. And yet it is surely surprising that I
should have a more distinct grasp of things which I realize are doubtful, un-
known and foreign to me, than I have of that which is true and known - my
own self. But I see what it is: my mind enjoys wandering off and will not yet
submit to being restrained within the bounds oftruth. Very well then; just this
once let us give it a completely free rein, so that after a while, when it is time to
tighten the reins, it may more readily submit to being curbed.
Let us consider the things which people commonly think they understand
most distinctly ofall; that is, the bodies which we touch and see. I do not mean
bodies in general- for general perceptions are apt to be somewhat more con-
fused- but one particular body. Let us take, for example, this piece ofwax. It
has just been taken from the honeycomb; it has not yet quite lost the taste of
the honey; it retains some of the scent of the flowers from which it was gath-
ered; its colour, shape and size are plain to see; it is hard, cold and can be
handled without difficulty; ifyou rap it with your knuckle it makes a sound. In
short, it has everything which appears necessary to enable a body to be known
as distinctly as possible. But even as I speak, I put the wax by the fire, and look:
the residual taste is eliminated, the smell goes away, the colour changes, the
shape is lost, the size increases; it becomes liquid and hot; you can hardly touch
it, and if you strike it, it no longer makes a sound. But does the same wax
remain? It must be admitted that it does; no one denies it, no one thinks
11
25. RENE DESCARTES
otherwise. So what was it in the wax that I understood with such distinctness?
Evidendy none of the features which I arrived at by means of the senses; for
whatever came under taste, smell, sight, touch or hearing has now altered -yet
the wax remains.
Perhaps the answer lies in the thought which now comes to my mind; namely,
the wax was not after all the sweetness of the honey, or the fragrance of the
flowers, or the whiteness, or the shape, or the sound, but was rather a body
which presented itselfto me in these various forms a litde while ago, but which
now exhibits different ones. But what exacdy is it that I am now imagining? Let
us concentrate, take away everything which does not belong to the wax, and see
what is left: merely something extended, flexible and changeable. But what is
meant here by "flexible" and "changeable"? Is it what I picture in my imagina-
tion: that this piece of wax is capable of changing from a round shape to a
square shape, or from a square shape to a triangular shape? Not at all; for I can
grasp that the wax is capable ofcoundess changes ofthis kind, yet I am unable
to run through this immeasurable number ofchanges in my imagination, from
which it follows that it is not the faculty ofimagination that gives me my grasp
ofthe wax as flexible and changeable. And what is meant by "extended"? Is the
extension of the wax also unknown? For it increases ifthe wax melts, increases
again ifit boils, and is greater still ifthe heat is increased. I would not be making
a correct judgement about the nature of wax unless I believed it capable of
being extended in many more different ways than I will ever encompass in my
imagination. I must therefore admit that the nature ofthis piece ofwax is in no
way revealed by my imagination, but is perceived by the mind alone. (I am
speaking ofthis particular piece ofwax; the point is even clearer with regard to
wax in general.) But what is this wax which is perceived by the mind alone?12
It
is of course the same wax which I see, which I touch, which I picture in my
imagination, in short the same wax which I thought it to be from the start. And
yet, and here is the point, the perception I have ofit13
is a case not ofvision or
touch or imagination- nor has it ever been, despite previous appearances- but
of purely mental scrutiny; and this can be imperfect and confused, as it was
before, or clear and distinct as it is now, depending on how carefully I concen-
trate on what the wax consists in.
But as I reach this conclusion I am amazed at how [weak and] prone to error
my mind is. For although I am thinking about these matters within myself,
silendy and without speaking, nonetheless the actual words bring me up short,
and I am almost tricked by ordinary ways oftalking. We say that we see the wax
itself, ifit is there before us, not that we judge it to be there from its colour or
shape; and this might lead me to conclude without more ado that knowledge of
the wax comes from what the eye sees, and not from the scrutiny of the mind
alone. But then ifl look out ofthe window and see men crossing the square, as
I just happen to have done, I normally say that I see the men themselves, just as
I say that I see the wax. Yet do I see any more than hats and coats which could
conceal automatons? I judge that they are men. And so something which I
thought I was seeing with my eyes is in fact grasped solely by the faculty of
judgement which is in my mind.
12
26. MEDITATIONS
However, one who wants to achieve knowledge above the ordinary level should
feel ashamed at having taken ordinary ways oftalking as a basis for doubt. So let
us proceed, and consider on which occasion my perception ofthe nature ofthe
wax was more perfect and evident. Was it when I first looked at it, and believed
I knew it by my external senses, or at least by what they call the "common"
sense - that is, the power of imagination? Or is my knowledge more perfect
now, after a more careful investigation of the nature of the wax and of the
means by which it is known? Any doubt on this issue would clearly be foolish;
for what distinctness was there in my earlier perception? Was there anything in
it which an animal could not possess? But when I distinguish the wax from its
outward forms - take the clothes off, as it were, and consider it naked - then
although my judgement may still contain errors, at least my perception now
requires a human mind.
But what am I to say about this mind, or about myself? (So far, remember, I
am not admitting that there is anything else in me except a mind.) What, I ask,
is this "I" which seems to perceive the wax so distinctly? Surely my awareness of
my own self is not merely much truer and more certain than my awareness of
the wax, but also much more distinct and evident. For if I judge that the wax
exists from the fact that I see it, clearly this same fact entails much more evi-
dently that I myselfalso exist. It is possible that what I see is not really the wax;
it is possible that I do not even have eyes with which to see anything. But when
I see, or think I see (I am not here distinguishing the two), it is simply not
possible that I who am now thinking am not something. By the same token, if
I judge that the wax exists from the fact that I touch it, the same result follows,
namely that I exist. Ifl judge that it exists from the fact that I imagine it, or for
any other reason, exactly the same thing follows. And the result that I have
grasped in the case ofthe wax may be applied to everything else located outside
me. Moreover, if my perception of the wax seemed more distinct14
after it was
established not just by sight or touch but by many other considerations, it must
be admitted that I now know myselfeven more distinctly. This is because every
consideration whatsoever which contributes to my perception ofthe wax, or of
any other body, cannot but establish even more effectively the nature of my
own mind. But besides this, there is so much else in the mind itselfwhich can
serve to make my knowledge of it more distinct, that it scarcely seems worth
going through the contributions made by considering bodily things.
I see that without any effort I have now finally got back to where I wanted. I
now know that even bodies are not strictly perceived by the senses or the faculty
of imagination but by the intellect alone, and that this perception derives not
from their being touched or seen but from their being understood; and in view
of this I know plainly that I can achieve an easier and more evident perception
ofmy own mind than ofanything else. But since the habit ofholding on to old
opinions cannot be set aside so quickly, I should like to stop here and meditate
for some time on this new knowledge I have gained, so as to fix it more deeply
in my memory.
13
27. LUDWIG WITTGENSTEIN
Notes
l " ... and in my dreams regularly represent to myself the same things" (French
version).
2 "... the place where they are, the time which measures their duration" (French
version).
3 "... yet I cannot doubt that he does allow this" (French version).
4 "... in the sciences" (added in French version).
5 "... nevertheless it is in my power to suspend my judgement" (French version).
6 "... puts into my mind" (French version).
7 "... or thought anything at all" (French version).
8 The word "only" is most naturally taken as going with "a thing that thinks," and
this interpretation is followed in the French version. When discussing this passage
with Gassendi, however, Descartes suggests that he meant the "only" to govern "in
the strict sense."
9 "... to see ifl am not something more" (added in French version).
lO Lat. maneat ("let it stand"), first edition. The second edition has the indicative
manet: "The proposition still stands, viz. that I am nonetheless something." The
French version reads: "without changing this supposition, I find that I am still
certain that I am something."
11 "... from this manner of conceiving things" (French version).
12 "... which can only be conceived by the understanding or the mind" (French
version).
13 "... or rather the act whereby it is perceived" (added in French version).
14 The French version has "more clear and distinct" and, at the end of this sentence,
"more evidently, distinctly and clearly."
2 On Certainty
Ludwig Wittgenstein
l If you do know that here is one hand/ we'll grant you all the rest. When
one says that such and such a proposition can't be proved, of course that does
not mean that it can't be derived from other propositions; any proposition can
be derived from other ones. But they may be no more certain than it is itself.
(On this a curious remark by H. Newman.)
2 From its seeming to me- or to everyone- to be so, it doesn't follow that
it is so. What we can ask is whether it can make sense to doubt it.
5 Whether a proposition can turn out false after all depends on what I make
count as determinants for that proposition.
7 My life shews that I know or am certain that there is a chair over there, or
a door, and so on.- I tell a friend, e.g. "Take that chair over there," "Shut the
door," etc. etc.
14
28. ON CERTAINTY
10 I know that a sick man is lying here? Nonsense! I am sitting at his bedside,
I am looking attentively into his face.- So I don't know, then, that there is a sick
man lying here? Neither the question nor the assertion makes sense. Any more
than the assertion "I am here," which I might yet use at any moment, ifsuitable
occasion presented itself.- Then is "2 x 2 = 4" nonsense in the same way, and not
a proposition ofarithmetic, apart from particular occasions? "2 x 2 = 4" is a true
proposition of arithmetic- not "on particular occasions" nor "always"- but the
spoken or written sentence "2 x 2 = 4" in Chinese might have a different meaning
or be out and out nonsense, and from this is seen that it is only in use that the
proposition has its sense. And "I know that there's a sick man lying here," used in
an unsuitable situation, seems not to be nonsense but rather seems matter-of-
course, only because one can fairly easily imagine a situation to fit it, and one
thinks that the words "I know that ... " are always in place where there is no
doubt, and hence even where the expression of doubt would be unintelligible.
20 "Doubting the existence of the external world" does not mean for ex-
ample doubting the existence of a planet, which later observations proved to
exist. - Or does Moore want to say that knowing that here is his hand is differ-
ent in kind from knowing the existence ofthe planet Saturn? Otherwise it would
be possible to point out the discovery of the planet Saturn to the doubters and
say that its existence has been proved, and hence the existence of the external
world as well.
24 The idealist's question would be something like: "What right have I not
to doubt the existence of my hands?" (And to that the answer can't be: I know
that they exist.) But someone who asks such a question is overlooking the fact
that a doubt about existence only works in a language-game. Hence, that we
should first have to ask: what would such a doubt be like?, and don't under-
stand this straight off.
31 The propositions which one comes back to again and again as if be-
witched- these I should like to expunge from philosophical language.
33 Thus we expunge the sentences that don't get us any further.
45 We got to know the nature ofcalculating by learning to calculate.
46 But then can't it be described how we satisfY ourselves of the reliability
of a calculation? 0 yes! Yet no rule emerges when we do so. -But the most
important thing is: The rule is not needed. Nothing is lacking. We do calculate
according to a rule, and that is enough.
47 This is how one calculates. Calculating is this. What we learn at school,
for example. Forget this transcendent certainty, which is connected with your
concept of spirit.
48 However, out ofa host ofcalculations certain ones might be designated
as reliable once for all, others as not yet fixed. And now, is this a logical distinc-
tion?
49 But remember: even when the calculation is something fixed for me,
this is only a decision for a practical purpose.
74 Can we say: a mistake doesn't only have a cause, it also has a ground?
I.e., roughly: when someone makes a mistake, this can be fitted into what he
knows aright.
15
29. LUDWIG WITTGENSTEIN
83 The truth ofcertain empirical propositions belongs to our frame ofref-
erence.
90 "I know" has a primitive meaning similar to and related to "I see"
("wissen," "videre"). And "I knew he was in the room, but he wasn't in the
room" is like "I saw him in the room, but he wasn't there." "I know" is sup-
posed to express a relation, not between me and the sense ofa proposition (like
"I believe") but between me and a fact. So that the fact is taken into my con-
sciousness. (Here is the reason why one wants to say that nothing that goes on
in the outer world is really known, but only what happens in the domain of
what are called sense-data.) This would give us a picture of knowing as the
perception ofan outer event through visual rays which project it as it is into the
eye and the consciousness. Only then the question at once arises whether one
can be certain of this projection. And this picture does indeed show how our
imagination presents knowledge, but not what lies at the bottom ofthis pres-
entation.
94 But I did not get my picture of the world by satisfYing myself of its
correctness; nor do I have it because I am satisfied of its correctness. No: it is
the inherited background against which I distinguish between true and false.
95 The propositions describing this world-picture might be part of a kind
ofmythology. And their role is like that ofrules ofa game; and the game can be
learned purely practically, without learning any explicit rules.
109 "An empirical proposition can be testetf' (we say). But how? and through
what?
ll0 What counts as its test? - "But is this an adequate test? And, ifso, must
it not be recognizable as such in logic?" -As ifgiving grounds did not come to
an end sometime. But the end is not an ungrounded presupposition: it is an
ungrounded way of acting.
117 Why is it not possible for me to doubt that I have never been on the
moon? And how could I try to doubt it?
First and foremost, the supposition that perhaps I have been there would
strike me as idle. Nothing would follow from it, nothing be explained by it. It
would not tie in with anything in my life.
When I say "Nothing speaks for, everything against it," this presupposes a
principle ofspeaking for and against. That is, I must be able to say what would
speak for it.
141 When we first begin to believe anything, what we believe is not a single
proposition, it is a whole system of propositions. (Light dawns gradually over
the whole.)
142 It is not single axioms that strike me as obvious, it is a system in which
consequences and premises give one another mutual support.
160 The child learns by believing the adult. Doubt comes after belief.
166 The difficulty is to realize the groundlessness of our believing.
191 Well, ifeverything speaks for an hypothesis and nothing against it - is
it then certainly true? One may designate it as such.- But does it certainly agree
with reality, with the facts?- With this question you are already going round in
a circle.
16
30. ON CERTAINTY
192 To be sure there is justification; but justification comes to an end.
193 What does this mean: the truth of a proposition is certain?
194 With the word "certain" we express complete conviction, the total ab-
sence ofdoubt, and thereby we seek to convince other people. That is subjective
certainty.
But when is something objectively certain? When a mistake is not possible.
But what kind ofpossibility is that? Mustn't mistake be logically excluded?
195 Ifl believe that I am sitting in my room when I am not, then I shall not
be said to have made a mistake. But what is the essential difference between this
case and a mistake?
196 Sure evidence is what we accept as sure, it is evidence that we go by in
acting surely, acting without any doubt.
What we call "a mistake" plays a quite special part in our language games,
and so too does what we regard as certain evidence.
199 The reason why the use ofthe expression "true or false" has something
misleading about it is that it is like saying "it tallies with the facts or it doesn't,"
and the very thing that is in question is what "tallying" is here.
200 Really "The proposition is either true or false" only means that it must
be possible to decide for or against it. But this does not say what the ground for
such a decision is like.
203 [Everything2 that we regard as evidence indicates that the earth already
existed long before my birth. The contrary hypothesis has nothing to confirm it
at all.
Ifeverything speaks for an hypothesis and nothing against it, is it objectively
certain? One can call it that. But does it necessarily agree with the world of
facts? At the very best it shows us what "agreement" means. We find it difficult
to imagine it to be false, but also difficult to make use ofit.]
What does this agreement consist in, ifnot in the fact that what is evidence in
these language games speaks for our proposition? (Tractatus Logico-Philosophicus)
204 Giving grounds, however, justifying the evidence, comes to an end; -
but the end is not certain propositions striking us immediately as true, i.e. it is
not a kind ofseeing on our part; it is our acting, which lies at the bottom ofthe
language-game.
205 If the true is what is grounded, then the ground is not true, nor yet
false.
209 The existence of the earth is rather part of the whole picture which
forms the starting-point of belieffor me.
211 Now it gives our way of looking at things, and our researches, their
form. Perhaps it was once disputed. But perhaps, for unthinkable ages, it has
belonged to the scaffolding ofour thoughts. (Every human being has parents.)
214 What prevents me from supposing that this table either vanishes or
alters its shape and colour when no one is observing it, and then when someone
looks at it again changes back to its old condition? - "But who is going to
suppose such a thing!"- one would feel like saying.
215 Here we see that the idea of "agreement with reality" does not have
any clear application.
17
31. LUDWIG WITTGENSTEIN
217 Ifsomeone supposed that all our calculations were uncertain and that
we could rely on none of them (justifying himself by saying that mistakes are
always possible) perhaps we would say he was crazy. But can we say he is in
error? Does he not just react differently? We rely on calculations, he doesn't; we
are sure, he isn't.
221 Can I be in doubt at wilP.
225 What I hold fast to is not one proposition but a nest ofpropositions.
226 Can I give the supposition that I have ever been on the moon any
serious consideration at all?
229 Our talk gets its meaning from the rest ofour proceedings.
230 We are asking ourselves: what do we do with a statement "I know
... "? For it is not a question of mental processes or mental states.
And that is how one must decide whether something is knowledge or not.
231 If someone doubted whether the earth had existed a hundred years
ago, I should not understand, for this reason: I would not know what such a
person would still allow to be counted as evidence and what not.
232 "We could doubt every single one of these facts, but we could not
doubt them all." Wouldn't it be more correct to say: "we do not doubt them
all." Our not doubting them all is simply our manner ofjudging, and therefore
of acting.
243 One says "I know" when one is ready to give compelling grounds. "I
know" relates to a possibility of demonstrating the truth. Whether someone
knows something can come to light, assuming that he is convinced ofit.
But ifwhat he believes is ofsuch a kind that the grounds that he can give are
no surer than his assertion, then he cannot say that he knows what he believes.
247 What would it be like to doubt now whether I have two hands? Why
can't I imagine it all? What would I believe ifi didn't believe that? So far I have
no system at all within which this doubt might exist.
248 I have arrived at the rock bottom ofmy convictions.
And one might almost say that these foundation-walls are carried by the whole
house.
250 My having two hands is, in normal circumstances, as certain as any-
thing that I could produce in evidence for it.
That is why I am not in a position to take the sight ofmy hand as evidence for
it.
253 At the foundation ofwell-founded belieflies beliefthat is not founded.
292 Further experiments cannotgive the lie to our earlier ones, at most they
may change our whole way oflooking at things.
336 But what men consider reasonable or unreasonable alters. At certain
periods men find reasonable what at other periods they found unreasonable.
And vice versa.
But is there no objective character here?
Very intelligent and well-educated people believe in the story of creation in
the Bible, while others hold it as proven false, and the grounds ofthe latter are
well known to the former.
341 That is to say, the questions that we raise and our doubts depend on the
18
32. ON CERTAINTY
fact that some propositions are exempt from doubt, are as it were like hinges on
which those turn.
342 That is to say, it belongs to the logic of our scientific investigations
that certain things are in deed not doubted.
343 But it isn't that the situation is like this: We just can)t investigate eve-
rything, and for that reason we are forced to rest content with assumption. If I
want the door to turn, the hinges must stay put.
344 My life consists in my being content to accept many things.
354 Doubting and non-doubting behaviour. There is the first only if there
is the second.
357 One might say: "'I know' expresses comfortable certainty, not the cer-
tainty that is still struggling."
358 Now I would like to regard this certainty, not as something akin to
hastiness or superficiality, but as a form oflife. (That is very badly expressed and
probably badly thought as well.)
359 But that means I want to conceive it as something that lies beyond
being justified or unjustified; as it were, as something animal.
380 I might go on: "Nothing in the world will convince me of the oppo-
site!" For me this fact is at the bottom of all knowledge. I shall give up other
things but not this.
382 That is not to say that nothing in the world will in fact be able to
convince me of anything else.
383 The argument "I may be dreaming" is senseless for this reason: ifl am
dreaming, this remark is being dreamed as well - and indeed it is also being
dreamed that these words have any meaning.
418 Is my understanding only blindness to my own lack of understanding?
It often seems so to me.
559 You must bear in mind that the language-game is so to say something
unpredictable. I mean: it is not based on grounds. It is not reasonable (or un-
reasonable).
It is there -like our life.
Notes
1 See G. E. Moore, "Proofofan External World", Proceedings ofthe British Academy,
Vol XXV, 1939; also "A Defence of Common Sense" in Contemporary British Phi-
losophy, 2nd Series, ed. J. H. Muirhead, 1925. Both papers are in Moore's Philosophi-
cal Papers, London, George Allen Unwin, 1959. (Editors.)
2 Passage crossed out in ms. (Editors.)
19
33. A. J. AVER
3 The Right to Be Sure
A.]. Ayer
Infallibility
The mistaken doctrine that knowing is an infallible state of mind may have
contributed to the view, which is sometimes held, that the only statements that
it is possible to know are those that are themselves in some way infallible. The
ground for this opinion is that ifone knows something to be true one cannot be
mistaken. As we remarked when contrasting knowledge with belief, it is incon-
sistent to say "I know but I may be wrong." But the reason why this is incon-
sistent is that saying "I know" offers a guarantee which saying "I may be wrong"
withdraws. It does not follow that for a fact to be known it must be such that no
one could be mistaken about it or such that it could not have been otherwise. It
is doubtful if there are any facts about which no one could be mistaken, and
while there are facts which could not be otherwise, they are not the only ones
that can be known. But how can this second point be reconciled with the fact
that what is known must be true? The answer is that the statement that what is
known must be true is ambiguous. It may mean that it is necessary that ifsome-
thing is known it is true; or it may mean that ifsomething is known, then it is a
necessary truth. The first ofthese propositions is correct; it restates the linguis-
tic fact that what is not true cannot properly be said to be known. But the
second is in general false. It would follow from the first only if all truths were
necessary, which is not the case. To put it another way, there is a necessary
transition from being known to being true; but that is not to say that what is
true, and known to be true, is necessary or certain in itself.
Ifwe are not to be bound by ordinary usage, it is still open to us to make it a
rule that only what is certain can be known. That is, we could decide, at least for
the purposes of philosophical discourse, not to use the word "know" except
with the implication that what was known was necessarily true, or, perhaps,
certain in some other sense. The consequence would be that we could still
speak of knowing the truth of a priori statements, such as those of logic and
pure mathematics; and if there were any empirical statements, such as those
describing the content of one's present experience, that were certain in them-
selves, they too might be included: but most ofwhat we now correcdy claim to
know would not be knowable, in this allegedly strict sense. This proposal is
feasible, but it does not appear to have anything much to recommend it. It is
not as if a statement by being necessary became incapable of being doubted.
Every schoolboy knows that it is possible to be unsure about a mathematical
truth. Whether there are any empirical statements which are in any important
sense indubitable is, as we shall see, a matter of dispute: if there are any they
20
34. THE RIGHT TO BE SURE
belong to a very narrow class. It is, indeed, important philosophically to distin-
guish between necessary and empirical statements, and in dealing with empiri-
cal statements to distinguish between different types and degrees of evidence.
But there are better ways of bringing out these distinctions than by tampering
with the meaning, or the application, ofthe verb "to know."
The Right to Be Sure
The answers which we have found for the questions we have so far been discuss-
ing have not yet put us in a position to give a complete account ofwhat it is to
know that something is the case. The first requirement is that what is known
should be true, but this is not sufficient; not even if we add to it the further
condition that one must be completely sure ofwhat one knows. For it is possi-
ble to be completely sure of something which is in fact true, but yet not to
know it. The circumstances may be such that one is not entitled to be sure. For
instance, a superstitious person who had inadvertently walked under a ladder
might be convinced as a result that he was about to suffer some misfortune; and
he might in fact be right. But it would not be correct to say that he knew that
this was going to be so. He arrived at his beliefby a process ofreasoning which
would not be generally reliable; so, although his prediction came true, it was
not a case of knowledge. Again, if someone were fully persuaded of a math-
ematical proposition by a proofwhich could be shown to be invalid, he would
not, without further evidence, be said to know the proposition, even though it
was true. But while it is not hard to find examples of true and fully confident
beliefs which in some ways fail to meet the standards required for knowledge, it
is not at all easy to determine exactly what these standards are.
One way oftrying to discover them would be to consider what would count
as satisfactory answers to the question How do you know? Thus people may be
credited with knowing truths of mathematics or logic if they are able to give a
valid proofofthem, or even if, without themselves being able to set out such a
proof, they have obtained this information from someone who can. Claims to
know empirical statements may be upheld by a reference to perception, or to
memory, or to testimony, or to historical records, or to scientific laws. But such
backing is not always strong enough for knowledge. Whether it is so or not
depends upon the circumstances of the particular case. If I were asked how I
knew that a physical object of a certain sort was in such and such a place, it
would, in general, be a sufficient answer for me to say that I could see it; but if
my eyesight were bad and the light were dim, this answer might not be suffi-
cient. Even though I was right, it might still be said that I did not really know
that the object was there. Ifl have a poor memory and the event which I claim
to remember is remote, my memory of it may still not amount to knowledge,
even though in this instance it does not fail me. If a witness is unreliable, his
unsupported evidence may not enable us to know that what he says is true, even
in a case where we completely trust him and he is not in fact deceiving us. In a
given instance it is possible to decide whether the backing is strong enough to
21
35. A. J. AYER
justifY a claim to knowledge. But to say in general how strong it has to be would
require our drawing up a list of the conditions under which perception, or
memory, or testimony, or other forms ofevidence are reliable. And this would
be a very complicated matter, if indeed it could be done at all.
Moreover, we cannot assume that, even in particular instances, an answer to
the question "How do you know?" will always be forthcoming. There may very
well be cases in which one knows that something is so without its being possible
to say how one knows it. I am not so much thinking now of claims to know
facts of immediate experience, statements like "I know that I feel pain," which
raise problems of their own into which we shall enter later on. In cases of this
sort it may be argued that the question how one knows does not arise. But even
when it clearly does arise, it may not find an answer. Suppose that someone
were consistently successful in predicting events of a certain kind, events, let us
say, which are not ordinarily thought to be predictable, like the results of a
lottery. If his run of successes were sufficiently impressive, we might very well
come to say that he knew which number would win, even though he did not
reach this conclusion by any rational method, or indeed by any method at all.
We might say that he knew it by intuition, but this would be to assert no more
than that he did know it but that we could not say how. In the same way, if
someone were consistently successful in reading the minds of others without
having any ofthe usual sort ofevidence, we might say that he knew these things
telepathically. But in default of any further explanation this would come down
to saying merely that he did know them, but not by any ordinary means. Words
like "intuition" and "telepathy" are brought in just to disguise the fact that no
explanation has been found.
But ifwe allow this sort ofknowledge to be even theoretically possible, what
becomes of the distinction between knowledge and true belief? How does our
man who knows what the results ofthe lottery will be differ from one who only
makes a series of lucky guesses? The answer is that, so far as the man himselfis
concerned, there need not be any difference. His procedure and his state of
mind, when he is said to know what will happen, may be exactly the same as
when it is said that he is only guessing. The difference is that to say that he
knows is to concede to him the right to be sure, while to say that he is only
guessing is to withhold it. Whether we make this concession will depend upon
the view which we take ofhis performance. Normally we do not say that people
know things unless they have followed one of the accredited routes to knowl-
edge. If someone reaches a true conclusion without appearing to have any ad-
equate basis for it, we are likely to say that he does not really know it. But if he
were repeatedly successful in a given domain, we might very well come to say
that he knew the facts in question, even though we could not explain how he
knew them. We should grant him the right to be sure, simply on the basis ofhis
success. This is, indeed, a point on which people's views might be expected to
differ. Not everyone would regard a successful run ofpredictions, however long
sustained, as being by itself a sufficient backing for a claim to knowledge. And
here there can be no question of proving that this attitude is mistaken. Where
there are recognized criteria for deciding when one has the right to be sure,
22
.r
I
36. THE RIGHT TO BE SURE
anyone who insists that their being satisfied is still not enough for knowledge
may be accused, for what the charge is worth, ofmisusing the verb "to know."
But it is possible to find, or at any rate to devise, examples which are not cov-
ered in this respect by any established rule of usage. Whether they are to count
as instances ofknowledge is then a question which we are left free to decide.
It does not, however, matter very greatly which decision we take. The main
problem is to state and assess the grounds on which these claims to knowledge
are made, to settle, as it were, the candidate's marks. It is a relatively unimpor-
tant question what titles we then bestow upon them. So long as we agree about
the marking, it is ofno great consequence where we draw the line between pass
and failure, or between the different levels of distinction. If we choose to set a
very high standard, we may find ourselves committed to saying that some of
what ordinarily passes for knowledge ought rather to be described as probable
opinion. And some critics will then take us to task for flouting ordinary usage.
But the question is purely one of terminology. It is to be decided, if at all, on
grounds of practical convenience.
One must not confuse this case, where the markings are agreed upon, and
what is in dispute is only the bestowal ofhonours, with the case where it is the
markings themselves that are put in question. For this second case is philo-
sophically important, in a way in which the other is not. The sceptic who asserts
that we do not know all that we think we know, or even perhaps that we do not
strictly know anything at all, is not suggesting that we are mistaken when we
conclude that the recognized criteria for knowing have been satisfied. Nor is he
primarily concerned with getting us to revise our usage of the verb "to know,"
any more than one who challenges our standards ofvalue is trying to make us
revise our usage ofthe word "good." The disagreement is about the application
of the word, rather than its meaning. What the sceptic contends is that our
markings are too high; that the grounds on which we are normally ready to
concede the right to be sure are worth less than we think; he may even go so far
as to say that they are not worth anything at all. The attack is directed, not
against the way in which we apply our standards of proof, but against these
standards themselves. It has, as we shall see, to be taken seriously because ofthe
arguments by which it is supported.
I conclude then that the necessary and sufficient conditions for knowing that
something is the case are first that what one is said to know be true, secondly
that one be sure ofit, and thirdly that one should have the right to be sure. This
right may be earned in various ways; but even if one could give a complete
description ofthem it would be a mistake to try to build it into the definition of
knowledge, just as it would be a mistake to try to incorporate our actual stand-
ards of goodness into a definition of good. And this being so, it turns out that
the questions which philosophers raise about the possibility of knowledge are
not all to be settled by discovering what knowledge is....
23
37. A. J. AYER
The Quest for Certainty
The quest for certainty has played a considerable part in the history ofphiloso-
phy: it has been assumed that without a basis of certainty all our claims to
knowledge must be suspect. Unless some things are certain, it is held, nothing
can be even probable. Unfortunately it has not been made clear exactly what is
being sought. Sometimes the word "certain" is used as a synonym for "neces-
sary" or for "a priori." It is said, for example, that no empirical statements are
certain, and what is meant by this is that they are not necessary in the way that
a priori statements are, that they can all be denied without self-contradiction.
Accordingly, some philosophers take a priori statements as their ideal. They
wish, like Leibniz, to put all true statements on a level with those offormallogic
or pure mathematics; or, like the existentialists, they attach a tragic significance
to the fact that this cannot be done. But it is perverse to see tragedy in what
could not conceivably be otherwise; and the fact that all empirical statements
are contingent, that even when true they can be denied without self-contradic-
tion, is itselfa matter ofnecessity. Ifempirical statements had the formal valid-
ity which makes the truths oflogic unassailable they could not do the work that
we expect of them; they would not be descriptive of anything that happens. In
demanding for empirical statements the safeguard of logical necessity, these
philosophers have failed to see that they would thereby rob them oftheir factual
content.
Neither is this the only way in which their ideal of a priori statements fails
them. Such statements are, indeed, unassailable, in the sense that, if they are
true, there are no circumstances in which they could have been false. One may
conceive of a world in which they had no useful application, but their being
useless would not render them invalid: even ifthe physical processes ofaddition
or subtraction could for some reason not be carried out, the laws ofarithmetic
would still hold good. But from the fact that a priori statements, ifthey are true,
are unassailable in this sense, it does not follow that they are immune from
doubt. For, as we have already remarked, it is possible to make mistakes in
mathematics or in logic. It is possible to believe an a priori statement to be true
when it is not. And we have seen that it is vain to look for an infallible state of
intuition, which would provide a logical guarantee that no mistake was being
made. Here too, it may be objected that the only reason that we have for con-
cluding that any given a priori statement is false is that it contradicts some other
which is true. That we can discover our errors shows that we have the power to
correct them. The fact that we sometimes find ourselves to be mistaken in ac-
cepting an a priori statement, so far from lending favour to the suggestion that
all those that we accept are false, is incompatible with it. But this still leaves it
open for us to be at fault in any particular case. There is no special set ofa priori
statements ofwhich it can be said that just these are beyond the reach ofdoubt.
In very many instances the doubt would not, indeed, be serious. If the validity
of some logical principle is put in question, one may be able to find a way of
proving or disproving it. Ifit be suggested that the proof itself is suspect, one
24
38. THE RIGHT TO BE SURE
may obtain reassurance by going over it again. When one has gone over it again
and satisfied oneself that there is nothing wrong with it, then to insist that it
may still not be valid, that the conclusion may not really have been proved, is
merely to pay lip service to human fallibility. The doubt is maintained indefi-
nitely, because nothing is going to count as its being resolved. And just for this
reason it is not serious. But to say that it is not serious is not logically to exclude
it. There can be doubt so long as there is the possibility oferror. And there must
be the possibility oferror with respect to any statement, whether empirical or a
priori, which is such that from the fact that someone takes it to be so it does not
follow logically that it is so. We have established this point in our discussion of
knowledge, and we have seen that it is not vitiated by the fact that in the case of
a priori statements there may be no other ground for accepting them than that
one sees them to be true.
Philosophers have looked to a priori statements for security because they
have assumed that inasmuch as these statements may themselves be certain, in
the sense of being necessary, they can be certainly known. As we have seen, it
may even be maintained that only what is certainly true can be certainly known.
But this, it must again be remarked, is a confusion. A priori statements can,
indeed, be known, not because they are necessary but because they are true and
because we may be entitled to feel no doubt about their truth. And the reason
why we are entitled to feel no doubt about their truth may be that we can prove
them, or even just that we can see them to be valid; in either case there is an
appeal to intuition, since we have at some point to claim to be able to see the
validity ofa proof. Ifthe validity ofevery proofhad to be proved in its turn, we
should fall into an infinite regress. But to allow that there are times when we
may justifiably claim the right to be sure of the truth ofan a priori statement is
not to allow that our intuitions are infallible. One is conceded the right to be
sure when one is judged to have taken every reasonable step towards making
sure: but this is still logically consistent with one's being in error. The discovery
ofthe error refutes the claim to knowledge; but it does not prove that the claim
was not, in the circumstances, legitimately made. The claim to know an a priori
statement is satisfied only ifthe statement is true; but it is legitimate ifit has the
appropriate backing, which may, in certain cases, consist in nothing more than
the statement's appearing to be self-evident. Even so, it may fail: but if such
claims were legitimate only when there was no logical possibility of error, they
could not properly be made at all.
Thus, ifthe quest for certainty is simply a quest for knowledge, ifsaying that
a statement is known for certain amounts to no more than saying that it is
known, it may find its object in a priori statements, though not indeed in them
uniquely. If, on the other hand, it is a search for conditions which exclude not
merely the fact, but even the possibility, of error, then knowledge of a priori
statements does not satisfY it. In neither case is the fact that these a priori state-
ments may themselves be certain, in the sense ofbeing necessary, relevant to the
issue. Or rather, as we have seen, it is relevant only ifwe arbitrarily decide to
make it so.
25
39. CATHERINE Z. ELGIN
4 Epistemology's End
Catherine Z. Elgin
Quarry
Unaccountable success, like inexplicable failure, disconcerts. Even when our
undertakings achieve their avowed objectives, we endeavor to understand them.
We wonder how our projects, practices, interests, and institutions fit into the
greater scheme ofthings, what they contribute to and derive from it. Our curi-
osity extends beyond our limited forays into art and science, beyond our paro-
chial concerns with commerce, politics, and law. We want to comprehend the
interlocking systems that support or thwart our efforts. Ifwe start out expecting
thereby to gain fame, fortune, and the love of admirable people, many of us
conclude that understanding itself is worth the candle. The epistemic quest
need serve no further end.
What makes for an acceptable epistemic framework depends on the kind of
excellence we are after and on the functions we expect it to perform in our
cognitive economy. Agents adopt a variety of cognitive stances with different
kinds and degrees ofintellectual merit. In doing epistemology, we discriminate
among such stances, segregating out those that are worthy of intellectual es-
teem. Different partitions of the cognitive realm underwrite different concep-
tions of epistemology's goals and vindicate the construction and employment
of epistemic frameworks of different kinds.
Epistemological theories typically share an abstract characterization of their
enterprise. They agree, for example, that epistemology is the study of the na-
ture, scope, and utility ofknowledge. But they disagree about how their shared
characterization is concretely to be realized. So they differ over their subject's
priorities and powers, resources and rewards, standards and criteria. To view
them as supplying alternative answers to the same questions is an oversimplifi-
cation. For they embody disagreements about what the real questions are and
what counts as answering them. We cannot hope to decide among competing
positions on the basis ofpoint-by-point comparisons, for their respective merits
and faults stubbornly refuse to line up. To understand a philosophical position
and evaluate it fairly requires understanding the network of commitments that
constitute it; for these commitments organize its domain, frame its problems,
and supply standards for the solution of those problems.
John Rawls invokes a distinction between procedures1
that extends to supply
a useful classification ofepistemological theories. A perfectprocedure recognizes
an independent criterion for a correct outcome and a method whose results -if
any - are guaranteed to satisfY that criterion. Our independent criterion for the
fair division ofa cake, let us assume, is that a fair division is an equal one.2
A cake-
26
40. EPISTEMOLOGY'S END
slicing procedure is perfect, then, just in case it yields an equal division when it
yields any division. A finely calibrated electronic cake slicer that partitioned each
cake it divided into equally large slices would provide a perfect procedure for
fairly dividing cakes. The device would not have to be capable ofdividing every
cake. It might, for example, be inoperative on geometrically irregular cakes. But
so long as every cake it divides is divided into equal sized slices, its use would be
a perfect procedure for fairly dividing cakes. An imperfect procedure recognizes
an independent criterion for a correct outcome but has no way to guarantee that
the criterion is satisfied. The criterion for a correct outcome in a criminal trial is
that the defendant is convicted ifand only ifhe is guilty. Trial by jury, represen-
tation by counsel, the rules ofevidence, and so on, are the means used to secure
that result. But the means are not perfect. Sometimes a wrong verdict is reached.
A pure procedure has no independent standard for a correct outcome. The pro-
cedure itself, when properly performed, determines what result is correct. And
unless the procedure is actually performed, there is no fact of the matter as to
which outcome is correct. A tournament is best construed as a pure procedure.
Other construals are sometimes offered, but they are less satisfactory. If a tour-
nament is construed as a perfect procedure for discovering the most able com-
petitor, it is plainly defective. Anyone can have an offday or a bad series. Sometimes
the best man doesn't win. And arguably, ifit is construed as an imperfect proce-
dure, it may be too imperfect. Consideration ofhow the parties fare overall may
be a better indication oftalent than hinging everything on their performance in
a single game or series. But if the tournament is a pure procedure, such consid-
erations are otiose. Winning the tournament is what makes a particular competi-
tor the champion. The Celtics became the 1984 NBA champions by winning
the playoffS. Nothing more was required; nothing less would do. A pure proce-
dural interpretation ofits function thus best explains how a tournament realizes
the goal of an athletic competition: it incontrovertibly establishes a winner.
This tripartite division presents an attractive device for classifYing epistemo-
logical theories. Extended to the epistemological realm, Rawls's division ena-
bles us to classifY theories on the basis ofdifferences in the sources and strength
of epistemic justification they demand. Very roughly the difference is this: Per-
fect procedural epistemologies demand conclusive reasons, ones that guarantee
the permanent acceptability of the judgments they vindicate. Imperfect proce-
dural epistemologies require convincing reasons, but they recognize that con-
vincing reasons need not be and typically are not conclusive. Pure procedural
epistemologies construe reasons as constitutive. The reasons that, iftrue, would
support a given claim, then, collectively amount to that claim. Plainly these
criteria cry out for explication. It is far from obvious what makes for a reason,
much less what makes for a conclusive, convincing, or constitutive reason.
Moreover, each criterion admits of multiple, divergent explications. There is,
for example, an array of perfect procedural theories whose members agree in
their demand for conclusive reasons but disagree about what makes a reason
conclusive. I do not want to enter into internecine squabbles here. Rather, I
will sketch the considerations that tell in favor of each procedural stance. For
present purposes, then, a rough characterization is enough.
27
41. CATHERINE Z. ELGIN
One point should be emphasized. Epistemology is normative. It concerns
what people ought to think and why. So recognizing the normativeness ofcen-
tral epistemological notions is crucial. A. reason for pis not just a consideration
that, as a matter of brute psychological fact, prompts a subject to take it that p.
It is a consideration that, ceteris paribus, confers some measure ofobligation to
do so. Other things being equal, given that reason robtains, Swould be (more
or less) epistemically irresponsible ifshe failed to take it that p. Other things, of
course, are not always equal. Reasons can be discredited or overridden. Even
given r, S would not be irresponsible ifshe failed to believe or suspect that p, in
circumstances where q also obtained. Thus, for example, symptoms that afford
a prima facie obligation to think that a child has chicken pox are overridden by
a blood test that discloses the absence of antibodies to the disease. Reasons,
moreover, vary in strength. And reasons ofdiffering strengths engender differ-
ent epistemic obligations. A weak reason may confer an obligation to suspect
that p; a weaker one, an obligation not to presume that -p. Thus red spots on
a previously uninfected child's torso give a pediatrician an obligation to suspect,
or at least not to exclude, that the child has chicken pox. But many other com-
mon conditions produce red spots, so it would be irresponsible to claim to
know, on the basis of the spots alone, that he has the disease.
Weak reasons often persuade. That is a matter of psychological fact. But,
- if reasons are conclusive, perfect procedural epistemology contends,
- if they are convincing, imperfect procedural epistemology contends,
- if they are constitutive ofp, pure procedural epistemology contends,
S ought to believe that p. Her reasons are good enough to secure the belief.
Being measures of the goodness of reasons, then, 'conclusive', 'convincing',
and 'constitutive' function normatively as well.
Perfect Procedural Epistemology
Ifthe truths it seeks are supposed to be antecedent and indifferent to our beliefs
about them, and the test for truth affords a conclusive reason to accept its re-
sults, an epistemological theory construes itselfas a perfect procedural position.
The standard is rigorous. Ifpis true and pentails q, qis also true. Still, p may fail
to be a conclusive reason for q. Suppose, for example, 'A calico cat swallowed
the canary' is true; then, 'A cat swallowed the canary' is also true. But the mere
truth of 'A calico cat swallowed the canary' does not convert Sam's belief that
the cat is the culprit into knowledge. IfSam is ignorant ofthe truth in question,
that truth is for him epistemically inert. Unless he has other reasons to fall back
on, Sam's belief that a cat swallowed the canary is but a lucky guess. For all he
knows, the canary could have been eaten by a hawk. According to perfect pro-
cedural epistemology, Sam does not know. For a perfect procedure provides a
guarantee. Having satisfied its standard, the sentences it sanctions are immune
to falsity and invulnerable to luck.
28
