In the preceding chapter we saw that there are two sorts of knowledge:
knowledge of things, and knowledge of truths. In this chapter we shall
be concerned exclusively with knowledge of things, of which in turn we
shall have to distinguish two kinds. Knowledge of things, when it is
of the kind we call knowledge by _acquaintance_, is essentially simpler
than any knowledge of truths, and logically independent of knowledge
of truths, though it would be rash to assume that human beings ever,
in fact, have acquaintance with things without at the same time knowing
some truth about them. Knowledge of things by _description_, on the
contrary, always involves, as we shall find in the course of the present
chapter, some knowledge of truths as its source and ground. But first of
all we must make clear what we mean by 'acquaintance' and what we mean
by 'description'.
We shall say that we have _acquaintance_ with anything of which we are
directly aware, without the intermediary of any process of inference
or any knowledge of truths. Thus in the presence of my table I am
acquainted with the sense-data that make up the appearance of my
table--its colour, shape, hardness, smoothness, etc.; all these are
things of which I am immediately conscious when I am seeing and touching
my table. The particular shade of colour that I am seeing may have many
things said about it--I may say that it is brown, that it is rather
dark, and so on. But such statements, though they make me know truths
about the colour, do not make me know the colour itself any better
than I did before so far as concerns knowledge of the colour itself, as
opposed to knowledge of truths about it, I know the colour perfectly and
completely when I see it, and no further knowledge of it itself is even
theoretically possible. Thus the sense-data which make up the
appearance of my table are things with which I have acquaintance, things
immediately known to me just as they are.
My knowledge of the table as a physical object, on the contrary, is not
direct knowledge. Such as it is, it is obtained through acquaintance
with the sense-data that make up the appearance of the table. We have
seen that it is possible, without absurdity, to doubt whether there is
a table at all, whereas it is not possible to doubt the sense-data. My
knowledge of the table is of the kind which we shall call 'knowledge
by description'. The table is 'the physical object which causes
such-and-such sense-data'. This describes the table by means of the
sense-data. In order to know anything at all about the table, we must
know truths connecting it with things with which we have acquaintance:
we must know that 'such-and-such sense-data are caused by a physical
object'. There is no state of mind in which we are directly aware of the
table; all our knowledge of the table is really knowledge of truths, and
the actual thing which is the table is not, strictly speaking, known
to us at all. We know a description, and we know that there is just one
object to which this description applies, though the object itself is
not directly known to us. In such a case, we say that our knowledge of
the object is knowledge by description.
All our knowledge, both knowledge of things and knowledge of truths,
rests upon acquaintance as its foundation. It is therefore important to
consider what kinds of things there are with which we have acquaintance.
Sense-data, as we have already seen, are among the things with which
we are acquainted; in fact, they supply the most obvious and striking
example of knowledge by acquaintance. But if they were the sole example,
our knowledge would be very much more restricted than it is. We should
only know what is now present to our senses: we could not know anything
about the past--not even that there was a past--nor could we know any
truths about our sense-data, for all knowledge of truths, as we shall
show, demands acquaintance with things which are of an essentially
different character from sense-data, the things which are sometimes
called 'abstract ideas', but which we shall call 'universals'. We have
therefore to consider acquaintance with other things besides sense-data
if we are to obtain any tolerably adequate analysis of our knowledge.
The first extension beyond sense-data to be considered is acquaintance
by _memory_. It is obvious that we often remember what we have seen or
heard or had otherwise present to our senses, and that in such cases we
are still immediately aware of what we remember, in spite of the fact
that it appears as past and not as present. This immediate knowledge by
memory is the source of all our knowledge concerning the past: without
it, there could be no knowledge of the past by inference, since we
should never know that there was anything past to be inferred.
The next extension to be considered is acquaintance by _introspection_.
We are not only aware of things, but we are often aware of being aware
of them. When I see the sun, I am often aware of my seeing the sun; thus
'my seeing the sun' is an object with which I have acquaintance. When
I desire food, I may be aware of my desire for food; thus 'my desiring
food' is an object with which I am acquainted. Similarly we may be
aware of our feeling pleasure or pain, and generally of the events which
happen in our minds. This kind of acquaintance, which may be called
self-consciousness, is the source of all our knowledge of mental things.
It is obvious that it is only what goes on in our own minds that can be
thus known immediately. What goes on in the minds of others is known
to us through our perception of their bodies, that is, through the
sense-data in us which are associated with their bodies. But for our
acquaintance with the contents of our own minds, we should be unable to
imagine the minds of others, and therefore we could never arrive at
the knowledge that they have minds. It seems natural to suppose that
self-consciousness is one of the things that distinguish men from
animals: animals, we may suppose, though they have acquaintance with
sense-data, never become aware of this acquaintance. I do not mean
that they _doubt_ whether they exist, but that they have never become
conscious of the fact that they have sensations and feelings, nor
therefore of the fact that they, the subjects of their sensations and
feelings, exist.
We have spoken of acquaintance with the contents of our minds as
_self_-consciousness, but it is not, of course, consciousness of our
_self_: it is consciousness of particular thoughts and feelings. The
question whether we are also acquainted with our bare selves, as opposed
to particular thoughts and feelings, is a very difficult one, upon which
it would be rash to speak positively. When we try to look into ourselves
we always seem to come upon some particular thought or feeling, and not
upon the 'I' which has the thought or feeling. Nevertheless there are
some reasons for thinking that we are acquainted with the 'I', though
the acquaintance is hard to disentangle from other things. To make clear
what sort of reason there is, let us consider for a moment what our
acquaintance with particular thoughts really involves.
When I am acquainted with 'my seeing the sun', it seems plain that I am
acquainted with two different things in relation to each other. On the
one hand there is the sense-datum which represents the sun to me, on the
other hand there is that which sees this sense-datum. All acquaintance,
such as my acquaintance with the sense-datum which represents the sun,
seems obviously a relation between the person acquainted and the object
with which the person is acquainted. When a case of acquaintance is one
with which I can be acquainted (as I am acquainted with my acquaintance
with the sense-datum representing the sun), it is plain that the person
acquainted is myself. Thus, when I am acquainted with my
seeing the sun, the whole fact with which I am acquainted is
'Self-acquainted-with-sense-datum'.
Further, we know the truth 'I am acquainted with this sense-datum'. It
is hard to see how we could know this truth, or even understand what is
meant by it, unless we were acquainted with something which we call 'I'.
It does not seem necessary to suppose that we are acquainted with a more
or less permanent person, the same to-day as yesterday, but it does seem
as though we must be acquainted with that thing, whatever its nature,
which sees the sun and has acquaintance with sense-data. Thus, in some
sense it would seem we must be acquainted with our Selves as opposed
to our particular experiences. But the question is difficult, and
complicated arguments can be adduced on either side. Hence, although
acquaintance with ourselves seems _probably_ to occur, it is not wise to
assert that it undoubtedly does occur.
We may therefore sum up as follows what has been said concerning
acquaintance with things that exist. We have acquaintance in sensation
with the data of the outer senses, and in introspection with the data of
what may be called the inner sense--thoughts, feelings, desires, etc.;
we have acquaintance in memory with things which have been data either
of the outer senses or of the inner sense. Further, it is probable,
though not certain, that we have acquaintance with Self, as that which
is aware of things or has desires towards things.
In addition to our acquaintance with particular existing things, we also
have acquaintance with what we shall call _universals_, that is to say,
general ideas, such as _whiteness_, _diversity_, _brotherhood_, and so
on. Every complete sentence must contain at least one word which stands
for a universal, since all verbs have a meaning which is universal. We
shall return to universals later on, in Chapter IX; for the present, it
is only necessary to guard against the supposition that whatever we can
be acquainted with must be something particular and existent. Awareness
of universals is called _conceiving_, and a universal of which we are
aware is called a _concept_.
It will be seen that among the objects with which we are acquainted
are not included physical objects (as opposed to sense-data), nor other
people's minds. These things are known to us by what I call 'knowledge
by description', which we must now consider.
By a 'description' I mean any phrase of the form 'a so-and-so' or
'the so-and-so'. A phrase of the form 'a so-and-so' I shall call an
'ambiguous' description; a phrase of the form 'the so-and-so' (in the
singular) I shall call a 'definite' description. Thus 'a man' is an
ambiguous description, and 'the man with the iron mask' is a definite
description. There are various problems connected with ambiguous
descriptions, but I pass them by, since they do not directly concern
the matter we are discussing, which is the nature of our knowledge
concerning objects in cases where we know that there is an object
answering to a definite description, though we are not acquainted with
any such object. This is a matter which is concerned exclusively with
definite descriptions. I shall therefore, in the sequel, speak simply of
'descriptions' when I mean 'definite descriptions'. Thus a description
will mean any phrase of the form 'the so-and-so' in the singular.
We shall say that an object is 'known by description' when we know that
it is 'the so-and-so', i.e. when we know that there is one object, and
no more, having a certain property; and it will generally be implied
that we do not have knowledge of the same object by acquaintance. We
know that the man with the iron mask existed, and many propositions
are known about him; but we do not know who he was. We know that the
candidate who gets the most votes will be elected, and in this case we
are very likely also acquainted (in the only sense in which one can
be acquainted with some one else) with the man who is, in fact, the
candidate who will get most votes; but we do not know which of the
candidates he is, i.e. we do not know any proposition of the form 'A is
the candidate who will get most votes' where A is one of the candidates
by name. We shall say that we have 'merely descriptive knowledge' of the
so-and-so when, although we know that the so-and-so exists, and although
we may possibly be acquainted with the object which is, in fact, the
so-and-so, yet we do not know any proposition '_a_ is the so-and-so',
where _a_ is something with which we are acquainted.
When we say 'the so-and-so exists', we mean that there is just one
object which is the so-and-so. The proposition '_a_ is the so-and-so'
means that _a_ has the property so-and-so, and nothing else has. 'Mr.
A. is the Unionist candidate for this constituency' means 'Mr. A. is
a Unionist candidate for this constituency, and no one else is'. 'The
Unionist candidate for this constituency exists' means 'some one is a
Unionist candidate for this constituency, and no one else is'. Thus,
when we are acquainted with an object which is the so-and-so, we know
that the so-and-so exists; but we may know that the so-and-so exists
when we are not acquainted with any object which we know to be the
so-and-so, and even when we are not acquainted with any object which, in
fact, is the so-and-so.
Common words, even proper names, are usually really descriptions. That
is to say, the thought in the mind of a person using a proper name
correctly can generally only be expressed explicitly if we replace the
proper name by a description. Moreover, the description required to
express the thought will vary for different people, or for the same
person at different times. The only thing constant (so long as the name
is rightly used) is the object to which the name applies. But so long as
this remains constant, the particular description involved usually makes
no difference to the truth or falsehood of the proposition in which the
name appears.
Let us take some illustrations. Suppose some statement made about
Bismarck. Assuming that there is such a thing as direct acquaintance
with oneself, Bismarck himself might have used his name directly to
designate the particular person with whom he was acquainted. In this
case, if he made a judgement about himself, he himself might be a
constituent of the judgement. Here the proper name has the direct use
which it always wishes to have, as simply standing for a certain object,
and not for a description of the object. But if a person who knew
Bismarck made a judgement about him, the case is different. What this
person was acquainted with were certain sense-data which he connected
(rightly, we will suppose) with Bismarck's body. His body, as a physical
object, and still more his mind, were only known as the body and the
mind connected with these sense-data. That is, they were known by
description. It is, of course, very much a matter of chance which
characteristics of a man's appearance will come into a friend's mind
when he thinks of him; thus the description actually in the friend's
mind is accidental. The essential point is that he knows that the
various descriptions all apply to the same entity, in spite of not being
acquainted with the entity in question.
When we, who did not know Bismarck, make a judgement about him, the
description in our minds will probably be some more or less vague mass
of historical knowledge--far more, in most cases, than is required to
identify him. But, for the sake of illustration, let us assume that we
think of him as 'the first Chancellor of the German Empire'. Here all
the words are abstract except 'German'. The word 'German' will, again,
have different meanings for different people. To some it will recall
travels in Germany, to some the look of Germany on the map, and so on.
But if we are to obtain a description which we know to be applicable,
we shall be compelled, at some point, to bring in a reference to a
particular with which we are acquainted. Such reference is involved in
any mention of past, present, and future (as opposed to definite dates),
or of here and there, or of what others have told us. Thus it would seem
that, in some way or other, a description known to be applicable to a
particular must involve some reference to a particular with which we
are acquainted, if our knowledge about the thing described is not to be
merely what follows _logically_ from the description. For example, 'the
most long-lived of men' is a description involving only universals,
which must apply to some man, but we can make no judgements concerning
this man which involve knowledge about him beyond what the description
gives. If, however, we say, 'The first Chancellor of the German Empire
was an astute diplomatist', we can only be assured of the truth of our
judgement in virtue of something with which we are acquainted--usually a
testimony heard or read. Apart from the information we convey to others,
apart from the fact about the actual Bismarck, which gives importance
to our judgement, the thought we really have contains the one or more
particulars involved, and otherwise consists wholly of concepts.
All names of places--London, England, Europe, the Earth, the Solar
System--similarly involve, when used, descriptions which start from some
one or more particulars with which we are acquainted. I suspect that
even the Universe, as considered by metaphysics, involves such a
connexion with particulars. In logic, on the contrary, where we are
concerned not merely with what does exist, but with whatever might or
could exist or be, no reference to actual particulars is involved.
It would seem that, when we make a statement about something only known
by description, we often _intend_ to make our statement, not in the form
involving the description, but about the actual thing described. That
is to say, when we say anything about Bismarck, we should like, if we
could, to make the judgement which Bismarck alone can make, namely,
the judgement of which he himself is a constituent. In this we are
necessarily defeated, since the actual Bismarck is unknown to us. But
we know that there is an object B, called Bismarck, and that B was an
astute diplomatist. We can thus _describe_ the proposition we should
like to affirm, namely, 'B was an astute diplomatist', where B is the
object which was Bismarck. If we are describing Bismarck as 'the first
Chancellor of the German Empire', the proposition we should like to
affirm may be described as 'the proposition asserting, concerning the
actual object which was the first Chancellor of the German Empire, that
this object was an astute diplomatist'. What enables us to communicate
in spite of the varying descriptions we employ is that we know there is
a true proposition concerning the actual Bismarck, and that however we
may vary the description (so long as the description is correct) the
proposition described is still the same. This proposition, which is
described and is known to be true, is what interests us; but we are not
acquainted with the proposition itself, and do not know it, though we
know it is true.
It will be seen that there are various stages in the removal from
acquaintance with particulars: there is Bismarck to people who knew him;
Bismarck to those who only know of him through history; the man with
the iron mask; the longest-lived of men. These are progressively further
removed from acquaintance with particulars; the first comes as near to
acquaintance as is possible in regard to another person; in the second,
we shall still be said to know 'who Bismarck was'; in the third, we do
not know who was the man with the iron mask, though we can know many
propositions about him which are not logically deducible from the fact
that he wore an iron mask; in the fourth, finally, we know nothing
beyond what is logically deducible from the definition of the man. There
is a similar hierarchy in the region of universals. Many universals,
like many particulars, are only known to us by description. But here,
as in the case of particulars, knowledge concerning what is known by
description is ultimately reducible to knowledge concerning what is
known by acquaintance.
The fundamental principle in the analysis of propositions containing
descriptions is this: _Every proposition which we can understand must be
composed wholly of constituents with which we are acquainted_.
We shall not at this stage attempt to answer all the objections which
may be urged against this fundamental principle. For the present, we
shall merely point out that, in some way or other, it must be possible
to meet these objections, for it is scarcely conceivable that we can
make a judgement or entertain a supposition without knowing what it is
that we are judging or supposing about. We must attach _some_ meaning
to the words we use, if we are to speak significantly and not utter mere
noise; and the meaning we attach to our words must be something with
which we are acquainted. Thus when, for example, we make a statement
about Julius Caesar, it is plain that Julius Caesar himself is not
before our minds, since we are not acquainted with him. We have in mind
some description of Julius Caesar: 'the man who was assassinated on the
Ides of March', 'the founder of the Roman Empire', or, perhaps, merely
'the man whose name was _Julius Caesar_'. (In this last description,
_Julius Caesar_ is a noise or shape with which we are acquainted.)
Thus our statement does not mean quite what it seems to mean, but means
something involving, instead of Julius Caesar, some description of him
which is composed wholly of particulars and universals with which we are
acquainted.
The chief importance of knowledge by description is that it enables us
to pass beyond the limits of our private experience. In spite of the
fact that we can only know truths which are wholly composed of terms
which we have experienced in acquaintance, we can yet have knowledge by
description of things which we have never experienced. In view of the
very narrow range of our immediate experience, this result is vital, and
until it is understood, much of our knowledge must remain mysterious and
therefore doubtful.