The Analysis of Mind, Bertrand Russell [best desktop ebook reader .txt] 📗

say that it “knew” the way to that place,

any more than a stone rolling down hill knows the way to the

valley.

 

On the features which distinguish knowledge from accuracy of

response in general, not much can be said from a behaviourist

point of view without referring to purpose. But the necessity of

SOMETHING besides accuracy of response may be brought out by the

following consideration: Suppose two persons, of whom one

believed whatever the other disbelieved, and disbelieved whatever

the other believed. So far as accuracy and sensitiveness of

response alone are concerned, there would be nothing to choose

between these two persons. A thermometer which went down for warm

weather and up for cold might be just as accurate as the usual

kind; and a person who always believes falsely is just as

sensitive an instrument as a person who always believes truly.

The observable and practical difference between them would be

that the one who always believed falsely would quickly come to a

bad end. This illustrates once more that accuracy of response to

stimulus does not alone show knowledge, but must be reinforced by

appropriateness, i.e. suitability for realizing one’s purpose.

This applies even in the apparently simple case of answering

questions: if the purpose of the answers is to deceive, their

falsehood, not their truth, will be evidence of knowledge. The

proportion of the combination of appropriateness with accuracy in

the definition of knowledge is difficult; it seems that both

enter in, but that appropriateness is only required as regards

the general type of response, not as regards each individual

instance.

 

II. I have so far assumed as unquestionable the view that the

truth or falsehood of a belief consists in a relation to a

certain fact, namely the objective of the belief. This view has,

however, been often questioned. Philosophers have sought some

intrinsic criterion by which true and false beliefs could be

distinguished.* I am afraid their chief reason for this search

has been the wish to feel more certainty than seems otherwise

possible as to what is true and what is false. If we could

discover the truth of a belief by examining its intrinsic

characteristics, or those of some collection of beliefs of which

it forms part, the pursuit of truth, it is thought, would be a

less arduous business than it otherwise appears to be. But the

attempts which have been made in this direction are not

encouraging. I will take two criteria which have been suggested,

namely, (1) self-evidence, (2) mutual coherence. If we can show

that these are inadequate, we may feel fairly certain that no

intrinsic criterion hitherto suggested will suffice to

distinguish true from false beliefs.

 

* The view that such a criterion exists is generally held by

those whose views are in any degree derived from Hegel. It may be

illustrated by the following passage from Lossky, “The Intuitive

Basis of Knowledge” (Macmillan, 1919), p. 268: “Strictly

speaking, a false judgment is not a judgment at all. The

predicate does not follow from the subject S alone, but from the

subject plus a certain addition C, WHICH IN NO SENSE BELONGS TO

THE CONTENT OF THE JUDGMENT. What takes place may be a process of

association of ideas, of imagining, or the like, but is not a

process of judging. An experienced psychologist will be able by

careful observation to detect that in this process there is

wanting just the specific element of the objective dependence of

the predicate upon the subject which is characteristic of a

judgment. It must be admitted, however, that an exceptional power

of observation is needed in order to distinguish, by means of

introspection, mere combination of ideas from judgments.”

 

(1) Self-evidence.—Some of our beliefs seem to be peculiarly

indubitable. One might instance the belief that two and two are

four, that two things cannot be in the same place at the same

time, nor one thing in two places, or that a particular buttercup

that we are seeing is yellow. The suggestion we are to examine is

that such: beliefs have some recognizable quality which secures

their truth, and the truth of whatever is deduced from them

according to self-evident principles of inference. This theory is

set forth, for example, by Meinong in his book, “Ueber die

Erfahrungsgrundlagen unseres Wissens.”

 

If this theory is to be logically tenable, self-evidence must not

consist merely in the fact that we believe a proposition. We

believe that our beliefs are sometimes erroneous, and we wish to

be able to select a certain class of beliefs which are never

erroneous. If we are to do this, it must be by some mark which

belongs only to certain beliefs, not to all; and among those to

which it belongs there must be none that are mutually

inconsistent. If, for example, two propositions p and q were

self-evident, and it were also self-evident that p and q could

not both be true, that would condemn self-evidence as a guarantee

of truth. Again, self-evidence must not be the same thing as the

absence of doubt or the presence of complete certainty. If we are

completely certain of a proposition, we do not seek a ground to

support our belief. If self-evidence is alleged as a ground of

belief, that implies that doubt has crept in, and that our

self-evident proposition has not wholly resisted the assaults of

scepticism. To say that any given person believes some things so

firmly that he cannot be made to doubt them is no doubt true.

Such beliefs he will be willing to use as premisses in reasoning,

and to him personally they will seem to have as much evidence as

any belief can need. But among the propositions which one man

finds indubitable there will be some that another man finds it

quite possible to doubt. It used to seem self-evident that there

could not be men at the Antipodes, because they would fall off,

or at best grow giddy from standing on their heads. But New

Zealanders find the falsehood of this proposition self-evident.

Therefore, if self-evidence is a guarantee of truth, our

ancestors must have been mistaken in thinking their beliefs about

the Antipodes self-evident. Meinong meets this difficulty by

saying that some beliefs are falsely thought to be self-evident,

but in the case of others it is self-evident that they are

self-evident, and these are wholly reliable. Even this, however,

does not remove the practical risk of error, since we may

mistakenly believe it self-evident that a certain belief is

self-evident. To remove all risk of error, we shall need an

endless series of more and more complicated self-evident beliefs,

which cannot possibly be realized in practice. It would seem,

therefore, that self-evidence is useless as a practical criterion

for insuring truth.

 

The same result follows from examining instances. If we take the

four instances mentioned at the beginning of this discussion, we

shall find that three of them are logical, while the fourth is a

judgment of perception. The proposition that two and two are four

follows by purely logical deduction from definitions: that means

that its truth results, not from the properties of objects, but

from the meanings of symbols. Now symbols, in mathematics, mean

what we choose; thus the feeling of self-evidence, in this case,

seems explicable by the fact that the whole matter is within our

control. I do not wish to assert that this is the whole truth

about mathematical propositions, for the question is complicated,

and I do not know what the whole truth is. But I do wish to

suggest that the feeling of self-evidence in mathematical

propositions has to do with the fact that they are concerned with

the meanings of symbols, not with properties of the world such as

external observation might reveal.

 

Similar considerations apply to the impossibility of a thing

being in two places at once, or of two things being in one place

at the same time. These impossibilities result logically, if I am

not mistaken, from the definitions of one thing and one place.

That is to say, they are not laws of physics, but only part of

the intellectual apparatus which we have manufactured for

manipulating physics. Their self-evidence, if this is so, lies

merely in the fact that they represent our decision as to the use

of words, not a property of physical objects.

 

Judgments of perception, such as “this buttercup is yellow,” are

in a quite different position from judgments of logic, and their

self-evidence must have a different explanation. In order to

arrive at the nucleus of such a judgment, we will eliminate, as

far as possible, the use of words which take us beyond the

present fact, such as “buttercup” and “yellow.” The simplest kind

of judgment underlying the perception that a buttercup is yellow

would seem to be the perception of similarity in two colours seen

simultaneously. Suppose we are seeing two buttercups, and we

perceive that their colours are similar. This similarity is a

physical fact, not a matter of symbols or words; and it certainly

seems to be indubitable in a way that many judgments are not.

 

The first thing to observe, in regard to such judgments, is that

as they stand they are vague. The word “similar” is a vague word,

since there are degrees of similarity, and no one can say where

similarity ends and dissimilarity begins. It is unlikely that our

two buttercups have EXACTLY the same colour, and if we judged

that they had we should have passed altogether outside the region

of self-evidence. To make our proposition more precise, let us

suppose that we are also seeing a red rose at the same time. Then

we may judge that the colours of the buttercups are more similar

to each other than to the colour of the rose. This judgment seems

more complicated, but has certainly gained in precision. Even

now, however, it falls short of complete precision, since

similarity is not prima facie measurable, and it would require

much discussion to decide what we mean by greater or less

similarity. To this process of the pursuit of precision there is

strictly no limit.

 

The next thing to observe (although I do not personally doubt

that most of our judgments of perception are true) is that it is

very difficult to define any class of such judgments which can be

known, by its intrinsic quality, to be always exempt from error.

Most of our judgments of perception involve correlations, as when

we judge that a certain noise is that of a passing cart. Such

judgments are all obviously liable to error, since there is no

correlation of which we have a right to be certain that it is

invariable. Other judgments of perception are derived from

recognition, as when we say “this is a buttercup,” or even merely

“this is yellow.” All such judgments entail some risk of error,

though sometimes perhaps a very small one; some flowers that look

like buttercups are marigolds, and colours that some would call

yellow others might call orange. Our subjective certainty is

usually a result of habit, and may lead us astray in

circumstances which are unusual in ways of which we are unaware.

 

For such reasons, no form of self-evidence seems to afford an

absolute criterion of truth. Nevertheless, it is perhaps true

that judgments having a high degree of subjective certainty are

more apt to be true than other judgments. But if this be the

case, it is a result to be demonstrated, not a premiss from which

to start in defining truth and falsehood. As an initial

guarantee, therefore, neither self-evidence nor subjective

certainty can be accepted as adequate.

 

(2) Coherence.—Coherence as the definition of truth is advocated

by idealists, particularly by those who in the main follow Hegel.

It is set forth ably in Mr. Joachim’s book,