THE PROBLEM OF ERROR
In the _Theætetus_ of Plato, Socrates has been discussing with
Theætetus what knowledge is, and when at last agreement seems to be
reached in the definition that {75} knowledge is true opinion, a new
difficulty occurs to Socrates:
"There is a point which often troubles me and is a great perplexity to
me both in regard to myself and to others. I cannot make out the
nature or origin of the mental experience to which I refer. How there
can be false opinion--that difficulty still troubles the eye of my
mind. Do we not speak of false opinion, and say that one man holds a
false and another a true opinion, as though there were some natural
distinction between them? All things and everything are either known
or not known. He who knows, cannot but know; and he who does not know,
cannot know.... Where, then, is false opinion? For if all things are
either known or unknown, there can be no opinion which is not
comprehended under this alternative, and so false opinion is excluded."
This difficulty may appear at first sight purely verbal, and we shall
perhaps be inclined to see the answer to it in the double use that we
make of the word knowledge. We use the word in two senses, in one of
which it includes all and everything that is or can be present to the
mind in thinking, and in another and narrower sense the word knowledge
means truth. It was in the narrow sense of the word that whatever is
not true is not knowledge that Socrates interpreted the meaning of the
Delphic oracle that had declared him the wisest of men. His wisdom
must be, he said, that whereas other men seemed to be wise and to know
something, he knew that he knew nothing. All men have opinion, but
opinion is not knowledge, though easily and generally mistaken for it.
His perplexity was to understand what actually this false opinion could
be which passed for knowledge. It could not be nothing at all, for
then it would simply mean ignorance; but in false opinion {76} some
object is present to the mind. Everything that the mind thinks of has
being. A thing may have being that does not exist if by existence is
meant the particular existence of an event in time, for most of the
things we think about are timeless--they are ideas, such as whiteness,
goodness, numbers and the properties of numbers, faith, love, and
such-like. All such ideas are called universals, because their reality
does not mean that they exist at one particular moment and no other,
but they are real, they have being. How, then, can there be anything
intermediate between being and not being, anything that is and also is
not, for this is what false opinion or error seems to be?
There is, then, a problem of error, and it is quite distinct from the
problem of truth. The problem of truth is to know by what criterion we
can test the agreement of our ideas with reality; the problem of error
is to know how there can be false opinion. There is false opinion, of
this no one needs to be convinced; but where its place is in the
fundamental scheme of the mental process, in what precisely it
consists, whether it is purely a negation or whether it has a positive
nature of its own, this is the problem we have now to consider.
There is an important distinction in logic between what is
contradictory and what is contrary. Of two contradictory propositions
one must be true, the other must be false; but of two contrary
propositions one must be false, but both may be false. Of
contradictory propositions one is always a pure negation, one declares
the non-existence of what the other affirms the existence; but of
contrary propositions each has a positive content, and both may be
false. A true proposition may be based on a false opinion, and it is
very important to have a clear idea of what we intend by false opinion.
We do not mean by false opinion such plainly false {77} propositions as
that two and two are five or that there may be no corners in a
square--such propositions are false, because they contradict
propositions that are self-evident. If anyone should seriously affirm
them, we should not, I think, say that such a one had a false opinion,
but that he failed, perhaps through some illusion, to understand the
meaning of the terms he was using. An example of what would now, I
suppose, be unquestionably regarded by everyone as error is that whole
body of opinion that found expression in the theory and practice of
witchcraft. This was once almost universally accepted, and though
probably at no period nor in any country was there not some one who
doubted or disbelieved, still the reasons of such doubt or disbelief
would probably be very different from those reasons which lead us to
reject it to-day. For witchcraft was grounded on a general belief that
spiritual agencies, beneficent and malign, were the cause of material
well-being or evil. This conception has now given place to the
mechanistic or naturalistic theory on which our modern physical science
is based. We interpret all physical occurrences as caused by material
agency. But this belief, quite as much as the belief in spiritual
agencies, is opinion, not knowledge, and it may be false. It is
conceivable that future generations will reject our scientific notions,
self-evident though they seem to us, as completely as we reject the
notions of the dark ages. It is even conceivable that the whole of our
modern science may come to appear to mankind as not even an
approximation to knowledge. Error, like illusion, may be universal.
No one whose opinion counts as a rational belief now holds that
sickness may be caused by the malign influence of the evil eye, and
that this influence may be neutralised by making the sign of the cross;
some, but very few, believe that a {78} sick man may be healed by the
prayers and anointing of righteous men; many believe that material
disease, however malignant, may be expelled from the body by faith;
while the majority of rational men, whatever independent religious
views they hold, regard sickness and disease as material in the
ordinary sense, and expect them to yield to drugs and treatment. Now,
of these various opinions some must be false, while all may be false.
Let us add some illustrations from philosophy. Some philosophers hold,
in common with general opinion, that sense experience is caused by
physical objects; others hold that there are no physical objects, but
that consciousness is the one and only reality; and there are others
who think that the reality that gives rise to our sense experience is
neither physical in the sense of a material thing, nor mental in the
sense of consciousness or thought, but is movement or change--change
that requires no support and is absolute. All these are opinions, and
may be false, and our belief that any one of them is true does not
depend on immediate experience, but on reasons. The best that can be
said in favour of any belief is that there is no reason for supposing
it false, and the worst that can be said against any belief is that
there is no reason for supposing it true. Our problem, then, is to
know what constitutes the nature of error in any one of these examples
if it is, as each one may be, false?
The instances we have given are all of them propositions or judgments,
or else conceptions formed out of propositions or judgments, the
purpose of which is to interpret experience. The actual experience
itself, in so far as it consists of the actual presence of the object
to the mind aware of it, is, as we have seen, neither truth nor error;
it simply is what it is. It is the conceptions by which we interpret
this experience that are {79} true or false. And our problem is that
the meaning or content of a conception, that which is present to the
mind when we make a judgment, is precisely the same whether the
conception is true or false, there is no distinctive mark or feature by
which we can know that in the one case the object of thought is a real
or actual fact, in the other an opinion to which no reality
corresponds. And, further, it seems exceedingly difficult to
understand in what way a non-reality can be present to the mind at all.
Let us now examine some attempts to solve this problem, and first of
all let us take the pragmatist solution. Pragmatism claims that it has
no difficulty in explaining error, because, as we have already seen, it
acknowledges no other test or criterion of truth except a pragmatic
one. Every proposition or judgment that we make must, in order to have
any meaning whatever, be relevant to some human purpose; every such
proposition is a truth-claim; and every truth-claim is tested by its
workability. Consequently, error is simply the failure of a
proposition to establish its claim by the practical test of working.
Propositions marked by such failure are errors. As there is no truth
independent of time, place, and circumstance, no irrelevant truth, no
truth independent of the conditions under which its claim is put
forward, there is no truth that may not become error. No judgment,
according to pragmatism, is an error pure and simple--that is to say,
it cannot come into existence as error, for it comes claiming truth,
and maintaining that claim until challenged; it becomes an error in
retrospect only, and always in relation to another judgment which
corrects it. Error does not characterise a class of judgments; it is
something that happens to a judgment, it is a judgment whose
truth-claim is rejected in reference to another judgment {80} which
succeeds. The essential thing in the pragmatist doctrine of error is
that in claiming to be true a judgment is not challenging comparison
with some independent reality, nor is it claiming to belong to a
timeless order of existence--to be eternal; it is claiming to fulfil
the particular purpose for which it has been called forth, whether that
purpose be practical or theoretical.
Let us now consider the explanation of error offered by the idealist
philosophy. In this view only the whole truth is wholly true; the
Absolute, as a perfect, concrete, individual system, is the ideal, and
all that falls short of it can only possess a degree of truth--a degree
which is greater or less according as it approximates to the ideal.
The degrees of truth are not quantitative, not a mixture of truth and
error, but a nearer or more distant approach to the ideal. There can
be no absolute error, because if truth is the whole, error, if it
exists at all, must in some way be included in truth. Clearly error
cannot as such be truth, and therefore it must follow that, in the
whole, error loses its character of error, and finds reconciliation of
its contradiction to truth. Error, then, if it is something, and not a
pure negation, is partial or incomplete truth; the perplexity and
contradiction that it gives rise to are incidental to our partial view.
Knowledge, it must seem to us, can exist only for omniscience. Unless
we know everything, we know nothing.
These two doctrines are in a sense the exact antithesis of one another.
They agree together in this, that in each the explanation of error
follows as a consequence of the conception of the nature of truth. The
pragmatist theory implies that there is no truth in any real sense, but
only more or less successful error. The idealist theory implies that
there is no real error, but only a variety in the degree of truth.
{81}
Most people, however, are convinced that truth and error are not
related to one another, nor to the circumstances that call forth belief
or disbelief. Let us now examine a theory that recognises this. There
are false judgments, and they need explanation; error has a nature of
its own. If a judgment is false, it is absolutely and unalterably
false; if it is true, it is unconditionally true and with no reserve.
No logical process, no psychological disposition, can make what is
false true. Error must lie in the nature of knowledge, and to discover
that nature we must understand the theory of knowledge and determine
the exact nature of the mental act in knowing. The first essential is
to distinguish the kind of knowledge to which truth and error can
apply. We pointed out in the second chapter that all knowledge rests
ultimately on immediate experience. In immediate experience the
relation between the mental act of knowing and the object that is known
is so simple that any question as to truth or error in regard to it is
unmeaning. To question the truth of immediate experience is to
question its existence; it is to ask if it is what it is, and this is
plainly unmeaning. But thinking, we said, is questioning experience in
order to know its content or meaning, and in thinking, the simplicity
of the relation which unites the mind to its object in immediate
experience is left behind, and a logical process of very great
complexity takes its place. It is in this complexity that the
possibility of error lies.
Let us look at it a little more closely. Knowing is a relation which
unites two things, one the mind that knows, the other the thing known.
In every act of knowing, something is present to the mind; if knowing
is simply awareness of this actually present something, we call it
immediate experience, we are acquainted with the object. But our
knowledge is not only of objects {82} immediately present to the mind
and with which we are therefore acquainted. Knowledge embraces the
past and future and the distant realms of space. Indeed were knowledge
only of what is actually present to the mind, it is difficult to
imagine that we could, in the ordinary meaning of the word, know
anything at all. I may be thinking, for example, of an absent friend;
all that is present to my mind is, it may be, a memory image, a faint
recall of his appearance on some one occasion, or perhaps a
recollection of the tone of his voice, or it may be the black marks on
white paper which I recognise as his handwriting. This image is
present to my mind, but the image is not the object, my friend, about
whom I think and make endless judgments, true and false. So also, if
what is present to the mind is affecting me through the external
senses, if it is a sense impression, it is clear that what is actually
present is not the whole object of which I am aware, but only a very
small part of it, or, it may be, no part of it at all, but something, a
sound, or an odour, that represents it. The immediate data of
consciousness are named by some philosophers sense data, by others,
presentations, by others images, and there is much controversy as to
their nature and existence, but with this controversy we are not here
concerned--we are seeking to make clear an obvious distinction, namely,
the distinction between knowledge by acquaintance and knowledge by
description.
What kind of knowledge is it that we acquire by description? Knowledge
about things with which we are not first acquainted. The most
important knowledge that we possess or acquire is knowledge of objects
which we know only by the knowledge we have about them--objects that we
know about without knowing them. They are not direct impressions on
our senses, {83} nor are they ideas known in actual experience. We
make judgments about them, and the subjects about which we make these
judgments are really composed of these judgments that we make about
them. To go back to our illustrations, we may know a great deal about
the evil eye, a malignant influence, disease, faith, healing,
causality, physical objects, without any acquaintance with them,
without even knowing that they exist. Such knowledge is descriptive,
and the objects are descriptions. Knowledge by description is never
quite simple, and is often very complex, for, besides the relation of
the mental act to the object known, there are the terms and relations
which are the elements in the judgment and the relations of the
judgments themselves. If we analyse a judgment, every word in which it
is expressed, whether it is a noun or a verb or a preposition or a
conjunction, conveys a distinct meaning, indicates a term or a
relation, each of which can be made a distinct object to the mind, and
all of which are combined in the single meaning the judgment expresses.
It is in this complexity that the possibility of error lies, and the
possibility increases as the complexity increases. All the terms and
the relations which a judgment contains depend on the knowledge we have
by acquaintance--that is to say, we are ultimately dependent on our
actual experience for all knowledge whatever, whether it is
acquaintance or description, for we can only describe in terms with
which we are acquainted; but in the judgment these elements are
combined into new objects, or a certain relation is declared to exist
between objects, and it is this combination of the elements of the
judgment that involves its truth or falsehood.
If this view of the nature of the mental act of knowing is accepted, we
are able to understand how false opinion {84} is consistent with the
fact that all knowledge is truth. We escape both the alternatives that
seemed to Socrates the only possible ones. "When a man has a false
opinion, does he think that which he knows to be some other thing which
he knows, and knowing both is he at the same time ignorant of both? Or
does he think of something which he does not know as some other thing
which he does not know?" No, neither; in error he thinks that
something that he knows is in a relation that he knows to some other
thing that he knows, when in fact that relation is not relating the two
things. The false proposition is not one in which the constituent
terms and relations are unknown or non-existent, but one in which a
combination of these terms and relations is thought to exist when in
fact it does not exist; and the true proposition is that in which the
combination thought to exist does exist. We can, therefore, if this
account be true, at least know what false opinion or error can be,
whether or not we have any means of deciding in regard to any
particular opinion that it is false.
There is one other theory, the last we shall notice. It is in one
respect the most important of all, namely, that it is the most direct
attempt to grapple with the problem of error. It is founded on a
theory of knowledge which we owe mainly to the profound and acute work
of a German philosopher (Meinong), and which at the present time is
being keenly discussed. It is an attempt to determine more exactly
than has yet been done the fundamental scheme of the mental life and
development. The brief account that I am now offering, I owe to a
paper by Prof. G. F. Stout on "Some Fundamental Points in the Theory of
Knowledge." We have seen that the problem of error is the difficulty
there is in conceiving how there can be any real thing, any real {85}
object of thought, intermediate between being and not-being. Error
seems to exist and yet to have a nature which is a negation of
existence, and it seems therefore to be a downright contradiction when
we affirm that error or false opinion can _be_--that there is a real
object of thought when we judge falsely. This theory meets the
difficulty directly by distinguishing in the mental act of knowing a
process that is neither perceiving nor thinking of things, and that
involves neither believing nor disbelieving on the one hand nor
desiring or willing on the other: this is the process of supposing.
Corresponding to this mental act of supposing, there is a distinct kind
of object intended or meant by the mind--an object that is neither a
sense datum nor an idea, nor a judgment, but a supposition. Also and
again corresponding to this mental act of supposing and its intended
object the supposition, there is a mode of being which is neither
existence nor non-existence, but is named subsistence. A supposition,
it is said, does not exist--it subsists. This thesis, it will easily
be understood, is based on an analysis, and deals with arguments that
touch the most fundamental problems of theory of knowledge. Moreover,
its presentment is excessively technical, and only those highly trained
in the habit of psychological introspection and skilled in
philosophical analysis are really competent to discuss it. It is not
possible to offer here anything but a simple outline of the part of the
theory that concerns the present problem. The actual experience of
knowing is a relation between two things, one of which is a mental
_act_, the act of perceiving or thinking or having ideas, and the other
is an _object_, that which is perceived or thought of. The act is a
particular mental existence, it is the act of a psychical individual.
The object is not included within the actual experience which is the
knowing of it, it is {86} that which is meant or intended by the
experience. The act, then, is the mental process of meaning or
intending, the object the thing meant or intended. The mental act
differs according to the kind of object intended. The act of
perceiving is the direction of the mind towards sense data and ideas;
the act of judging is the direction of the mind towards judgments or
propositions about things, propositions that affirm or deny relations
between things; the act of supposing is different from both these--it
is the direction of the mind towards suppositions. Suppositions differ
from ideas in this, that they may be either positive or negative,
whereas ideas are never negative. This may seem to contradict
experience. Can we not, for example, have an idea of not-red just as
well as an idea of red? No, the two ideas can easily be seen to be one
and the same; in each case it is red we are actually acquainted with,
and the difference is in affirming or denying existence to the one
idea. The difference is in our judgment, which may be affirmative or
negative. A supposition is like a judgment in this respect; it may be
either affirmative or negative, but it differs from a judgment in
another respect, that while a judgment always conveys a conviction,
always expresses belief or disbelief, a supposition does not--it is
neither believed nor disbelieved.
Before I show the application of this analysis of knowledge to the
problem of error, let me try and clear up its obscurity, for
undoubtedly it is difficult to comprehend. Its difficulty lies in
this, that though all the ideas with which it deals are quite
familiar--suppositions, real and unreal possibilities, fulfilled and
non-fulfilled beliefs--yet it seems to run counter to all our notions
of the extreme simplicity of the appeal to reality. It seems strange
and paradoxical to our ordinary habit {87} of thinking to affirm that
there are real things and real relations between things which though
real yet do not exist, and also that non-existent realities are not
things that once were real but now are nought--they are things that
subsist. Yet this is no new doctrine. The most familiar case of such
realities is that of numbers. The Greeks discovered that numbers do
not exist--that is to say, that their reality is of another kind to
that which we denote by existence. Numbers are realities, otherwise
there would be no science of mathematics. Pythagoras (about 540-500
B.C.) taught that numbers are the reality from which all else is
derived. And there are many other things of the mind that seem indeed
to be more real than the things of sense. It is this very problem of
error that brings into relief this most important doctrine.
Now let us apply this theory of the supposition to the problem of
error, and we shall then see how there can be an object present to the
mind when we judge falsely, and also that the object is the same
whether we judge truly or falsely. Suppositions are real
possibilities; they are alternatives that may be fulfilled or that may
never be fulfilled. These real possibilities, or these possible
alternatives, are objects of thought; they do not belong to the mental
act of thinking; they are not in the mind, but realities present to the
mind. In mere supposing they are present as alternatives; in judging,
we affirm of them or deny of them the relation to general reality that
they are fulfilled. Judgments therefore are true or false accordingly
as the fulfilment they affirm does or does not agree with reality. In
this way, then, we may answer the perplexing question, How can there be
an object of thought in a false judgment? The answer is, that the
objects of thought about which we make judgments are suppositions, and
our judgments {88} concern their fulfilment, and their fulfilment is a
relation external to them--it is their agreement or disagreement with
reality.