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

“The Nature of Truth”

(Oxford, 1906). According to this view, any set of propositions

other than the whole of truth can be condemned on purely logical

grounds, as internally inconsistent; a single proposition, if it

is what we should ordinarily call false, contradicts itself

irremediably, while if it is what we should ordinarily call true,

it has implications which compel us to admit other propositions,

which in turn lead to others, and so on, until we find ourselves

committed to the whole of truth. One might illustrate by a very

simple example: if I say “so-and-so is a married man,” that is

not a self-subsistent proposition. We cannot logically conceive

of a universe in which this proposition constituted the whole of

truth. There must be also someone who is a married woman, and who

is married to the particular man in question. The view we are

considering regards everything that can be said about any one

object as relative in the same sort of way as “so-and-so is a

married man.” But everything, according to this view, is

relative, not to one or two other things, but to all other

things, so that from one bit of truth the whole can be inferred.

 

The fundamental objection to this view is logical, and consists

in a criticism of its doctrine as to relations. I shall omit this

line of argument, which I have developed elsewhere.* For the

moment I will content myself with saying that the powers of logic

seem to me very much less than this theory supposes. If it were

taken seriously, its advocates ought to profess that any one

truth is logically inferable from any other, and that, for

example, the fact that Caesar conquered Gaul, if adequately

considered, would enable us to discover what the weather will be

to-morrow. No such claim is put forward in practice, and the

necessity of empirical observation is not denied; but according

to the theory it ought to be.

 

* In the article on “The Monistic Theory of Truth” in

“Philosophical Essays” (Longmans, 1910), reprinted from the

“Proceedings of the Aristotelian Society,” 1906-7.

 

Another objection is that no endeavour is made to show that we

cannot form a consistent whole composed partly or wholly of false

propositions, as in a novel. Leibniz’s conception of many

possible worlds seems to accord much better with modern logic and

with the practical empiricism which is now universal. The attempt

to deduce the world by pure thought is attractive, and in former

times was largely supposed capable of success. But nowadays most

men admit that beliefs must be tested by observation, and not

merely by the fact that they harmonize with other beliefs. A

consistent fair-ytale is a different thing from truth, however

elaborate it may be. But to pursue this topic would lead us into

difficult technicalities; I shall therefore assume, without

further argument, that coherence is not sufficient as a

definition of truth.

 

III. Many difficult problems arise as regards the verifiability

of beliefs. We believe various things, and while we believe them

we think we know them. But it sometimes turns out that we were

mistaken, or at any rate we come to think we were. We must be

mistaken either in our previous opinion or in our subsequent

recantation; therefore our beliefs are not all correct, and there

are cases of belief which are not cases of knowledge. The

question of verifiability is in essence this: can we discover any

set of beliefs which are never mistaken or any test which, when

applicable, will always enable us to discriminate between true

and false beliefs? Put thus broadly and abstractly, the answer

must be negative. There is no way hitherto discovered of wholly

eliminating the risk of error, and no infallible criterion. If we

believe we have found a criterion, this belief itself may be

mistaken; we should be begging the question if we tried to test

the criterion by applying the criterion to itself.

 

But although the notion of an absolute criterion is chimerical,

there may be relative criteria, which increase the probability of

truth. Common sense and science hold that there are. Let us see

what they have to say.

 

One of the plainest cases of verification, perhaps ultimately the

only case, consists in the happening of something expected. You

go to the station believing that there will be a train at a

certain time; you find the train, you get into it, and it starts

at the expected time This constitutes verification, and is a

perfectly definite experience. It is, in a sense, the converse of

memory instead of having first sensations and then images

accompanied by belief, we have first images accompanied by belief

and then sensations. Apart from differences as to the time-order

and the accompanying feelings, the relation between image and

sensation is closely similar in the two cases of memory and

expectation; it is a relation of similarity, with difference as

to causal efficacy—broadly, the image has the psychological but

not the physical effects that the sensation would have. When an

image accompanied by an expectation-belief is thus succeeded by a

sensation which is the “meaning” of the image, we say that the

expectation-belief has been verified. The experience of

verification in this sense is exceedingly familiar; it happens

every time that accustomed activities have results that are not

surprising, in eating and walking and talking and all our daily

pursuits.

 

But although the experience in question is common, it is not

wholly easy to give a theoretical account of it. How do we know

that the sensation resembles the previous image? Does the image

persist in presence of the sensation, so that we can compare the

two? And even if SOME image does persist, how do we know that it

is the previous image unchanged? It does not seem as if this line

of inquiry offered much hope of a successful issue. It is better,

I think, to take a more external and causal view of the relation

of expectation to expected occurrence. If the occurrence, when it

comes, gives us the feeling of expectedness, and if the

expectation, beforehand, enabled us to act in a way which proves

appropriate to the occurrence, that must be held to constitute

the maximum of verification. We have first an expectation, then a

sensation with the feeling of expectedness related to memory of

the expectation. This whole experience, when it occurs, may be

defined as verification, and as constituting the truth of the

expectation. Appropriate action, during the period of

expectation, may be regarded as additional verification, but is

not essential. The whole process may be illustrated by looking up

a familiar quotation, finding it in the expected words, and in

the expected part of the book. In this case we can strengthen the

verification by writing down beforehand the words which we expect

to find.

 

I think all verification is ultimately of the above sort. We

verify a scientific hypothesis indirectly, by deducing

consequences as to the future, which subsequent experience

confirms. If somebody were to doubt whether Caesar had crossed

the Rubicon, verification could only be obtained from the future.

We could proceed to display manuscripts to our historical

sceptic, in which it was said that Caesar had behaved in this

way. We could advance arguments, verifiable by future experience,

to prove the antiquity of the manuscript from its texture,

colour, etc. We could find inscriptions agreeing with the

historian on other points, and tending to show his general

accuracy. The causal laws which our arguments would assume could

be verified by the future occurrence of events inferred by means

of them. The existence and persistence of causal laws, it is

true, must be regarded as a fortunate accident, and how long it

will continue we cannot tell. Meanwhile verification remains

often practically possible. And since it is sometimes possible,

we can gradually discover what kinds of beliefs tend to be

verified by experience, and what kinds tend to be falsified; to

the former kinds we give an increased degree of assent, to the

latter kinds a diminished degree. The process is not absolute or

infallible, but it has been found capable of sifting beliefs and

building up science. It affords no theoretical refutation of the

sceptic, whose position must remain logically unassailable; but

if complete scepticism is rejected, it gives the practical method

by which the system of our beliefs grows gradually towards the

unattainable ideal of impeccable knowledge.

 

IV. I come now to the purely formal definition of the truth or

falsehood of a belief. For this definition it is necessary first

of all to consider the derivation of the objective reference of a

proposition from the meanings of its component words or images.

 

Just as a word has meaning, so a proposition has an objective

reference. The objective reference of a proposition is a function

(in the mathematical sense) of the meanings of its component

words. But the objective reference differs from the meaning of a

word through the duality of truth and falsehood. You may believe

the proposition “to-day is Tuesday” both when, in fact, to-day is

Tuesday, and when to-day is not Tuesday. If to-day is not

Tuesday, this fact is the objective of your belief that to-day is

Tuesday. But obviously the relation of your belief to the fact is

different in this case from what it is in the case when to-day is

Tuesday. We may say, metaphorically, that when to-day is Tuesday,

your belief that it is Tuesday points TOWARDS the fact, whereas

when to-day is not Tuesday your belief points AWAY FROM the fact.

Thus the objective reference of a belief is not determined by the

fact alone, but by the direction of the belief towards or away

from the fact.* If, on a Tuesday, one man believes that it is

Tuesday while another believes that it is not Tuesday, their

beliefs have the same objective, namely the fact that it is

Tuesday but the true belief points towards the fact while the

false one points away from it. Thus, in order to define the

reference of a proposition we have to take account not only of

the objective, but also of the direction of pointing, towards the

objective in the case of a true proposition and away from it in

the case of a false one.

 

* I owe this way of looking at the matter to my friend Ludwig

Wittgenstein.

 

This mode of stating the nature of the objective reference of a

proposition is necessitated by the circumstance that there are

true and false propositions, but not true and false facts. If

to-day is Tuesday, there is not a false objective “to-day is not

Tuesday,” which could be the objective of the false belief

“to-day is not Tuesday.” This is the reason why two beliefs which

are each other’s contradictories have the same objective. There

is, however, a practical inconvenience, namely that we cannot

determine the objective reference of a proposition, according to

this definition, unless we know whether the proposition is true

or false. To avoid this inconvenience, it is better to adopt a

slightly different phraseology, and say: The “meaning” of the

proposition “to-day is Tuesday” consists in pointing to the fact

“to-day is Tuesday” if that is a fact, or away from the fact

“to-day is not Tuesday” if that is a fact. The “meaning” of the

proposition “to-day is not Tuesday” will be exactly the opposite.

By this hypothetical form we are able to speak of the meaning of

a proposition without knowing whether it is true or false.

According to this definition, we know the meaning of a

proposition when we know what would make it true and what would

make it false, even if we do not know whether it is in fact true

or false.

 

The meaning of a proposition is derivative from