Knowledge Through Direct Experience and Description

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'.

In the previous chapter, we saw that there are two kinds of knowledge: knowledge of things and knowledge of truths. In this chapter, we will focus only on knowledge of things. We will need to distinguish two kinds of knowledge of things. The kind we call knowledge by acquaintance is fundamentally simpler than any knowledge of truths. Knowledge by acquaintance is also logically independent of knowledge of truths. Still, it would be rash to assume that humans ever actually have acquaintance with things without also knowing some truth about them. Knowledge of things by description, however, always depends on some knowledge of truths as its source and foundation. We will see this dependence as the chapter proceeds. But first, 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.

We will say that we have acquaintance with anything we are directly aware of. This awareness does not depend on any process of inference or any knowledge of truths. So when I am near my table, I am acquainted with the sense-data that make up its appearance. These include its colour, shape, hardness, smoothness, and so on. I am immediately conscious of all these things when I see and touch my table. Many things may be said about the particular shade of colour I see. I may say that the colour is brown, that it is rather dark, and so on. But although these statements give me knowledge of truths about the colour, they do not improve my knowledge of the colour itself. As far as knowing the colour itself is concerned, rather than knowing truths about it, I know it perfectly and completely when I see it. No further knowledge of the colour itself is possible, even in theory. So the sense-data that make up my table’s appearance are things with which I have acquaintance. I know these things directly, 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.

By contrast, my knowledge of the table as a physical object is not direct knowledge. Such knowledge as I have comes through acquaintance with the sense-data that make up the table’s appearance. We have seen that we can reasonably doubt whether there is a table at all. But we cannot doubt the sense-data. My knowledge of the table is what we will call 'knowledge by description'. The table is 'the physical object that causes such-and-such sense-data'. This description identifies the table through the sense-data. To know anything at all about the table, we must know truths connecting the table with things we know directly. 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. Strictly speaking, we do not know the actual thing that is the table at all. We know a description, and we know that exactly one object fits this description. Yet we do not know the object itself directly. 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.

All our knowledge, both of things and of truths, is based on acquaintance. So we need to consider what kinds of things we have acquaintance with.

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.

As we have already seen, sense-data are among the things we know through acquaintance. In fact, sense-data provide the most obvious and striking example of knowledge by acquaintance. But if sense-data were the only example, our knowledge would be much more limited than it is. We would know only what is now present to our senses. We could know nothing about the past, not even that there was a past. Nor could we know any truths about our sense-data. For, as we will show, all knowledge of truths requires acquaintance with things fundamentally different from sense-data. These things are sometimes called 'abstract ideas', but we will call them 'universals'. So, to analyze our knowledge with any reasonable adequacy, we must consider acquaintance with things other than sense-data.

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 first kind of acquaintance beyond sense-data we will consider is acquaintance through memory. Clearly, we often remember what we have seen, heard, or experienced through our other senses. In these cases, we are still directly aware of what we remember, although we experience it as past, not present. This direct knowledge through memory is the source of all our knowledge about the past. Without memory, we could not gain knowledge of the past by inference. We would never know there was anything in the past to draw conclusions about.

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.

The next kind of acquaintance to consider is acquaintance through introspection. We are not only aware of things, but often aware that we are aware of them. When I see the sun, I am often aware that I am seeing the sun. So '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. So 'my desiring food' is an object with which I am acquainted. Similarly, we may be aware of feeling pleasure or pain, and more generally of events in our minds. This kind of acquaintance may be called self-consciousness. It is the source of all our knowledge of mental things. Clearly, only events in our own minds can be known directly in this way. We know what happens in other people's minds through our perception of their bodies. In other words, we know through the sense-data within us that are associated with their bodies. Without acquaintance with the contents of our own minds, we could not imagine the minds of others. We could therefore never come to know that other people have minds. It seems natural to suppose that self-consciousness is one of the things that distinguish humans from animals. We may suppose that animals, though acquainted with sense-data, never become aware of this acquaintance. I do not mean that animals doubt whether they exist. I mean that animals have never become conscious of having sensations and feelings. Nor, therefore, have animals become conscious that they themselves, as the subjects experiencing those 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.

We have called acquaintance with the contents of our minds self-consciousness. But of course, such awareness is not consciousness of our self. It is consciousness of particular thoughts and feelings. Are we also acquainted with our selves alone, apart from particular thoughts and feelings? The question is very difficult, and it would be rash to give a definite answer. When we look within ourselves, we always seem to find some particular thought or feeling. We do not seem to find the 'I' that has the thought or feeling. Nevertheless, there are some reasons to think we are acquainted with the 'I'. But this acquaintance is hard to separate from other things. To clarify these reasons, 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'.

When I am acquainted with 'my seeing the sun', I seem clearly to know two different things related to each other. One is the sense-datum that represents the sun to me. The other is whatever sees this sense-datum. All acquaintance seems clearly to be a relationship between the person acquainted and the object they are acquainted with. My acquaintance with the sense-datum representing the sun is one example. When I can be acquainted with an instance of acquaintance, the person acquainted is clearly myself. For example, I am acquainted with my own acquaintance with the sense-datum representing the sun. So, when I am acquainted with my seeing the sun, the whole fact I am acquainted with 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.

Further, we know the truth 'I am acquainted with this sense-datum'. How could we know this truth, or even understand its meaning, without being acquainted with something we call 'I'? It is hard to see how we could. We do not seem to need direct acquaintance with a more or less permanent person, the same today as yesterday. But we do seem to need acquaintance with whatever sees the sun and is acquainted with sense-data, whatever its nature. Thus, in some sense, we seem to need acquaintance with our Selves, as distinct from our particular experiences. But the question is difficult, and complex arguments can be made on either side. So, although acquaintance with ourselves seems probably to occur, it is unwise to claim that such acquaintance definitely occurs.

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.

We can therefore summarize what we have said about acquaintance with things that exist as follows. Through sensation, we are acquainted with the data of our outer senses. Through introspection, we are acquainted with the data of what we may call the inner sense. These inner data include thoughts, feelings, desires, and so on. Through memory, we are acquainted with things previously experienced through either the outer senses or the inner sense. Further, we are probably, though not certainly, acquainted with the Self as what is aware of things or desires 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.

Besides our acquaintance with particular things that exist, we also have acquaintance with what we will call universals. These are general ideas, such as whiteness, diversity, brotherhood, and so on. Every complete sentence must contain at least one word that stands for a universal, because all verbs have universal meanings. We will return to universals later, in Chapter IX. For now, we only need to avoid assuming that everything we can be acquainted with must be particular and exist. Awareness of universals is called conceiving, and a universal we are aware of 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.

As we can see, the objects we are acquainted with do not include physical objects (as distinct from sense-data). Nor do they include other people's minds. We know physical objects and other people's minds through what I call 'knowledge by description'. We must now consider this kind of knowledge.

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.

By a 'description' I mean any phrase of the form 'a so-and-so' or 'the so-and-so'. I will call a phrase of the form 'a so-and-so' an 'ambiguous' description. I will call a phrase of the form 'the so-and-so' (in the singular) a 'definite' description. Thus 'a man' is an ambiguous description, and 'the man with the iron mask' is a definite description. Ambiguous descriptions raise various problems, but I will set those problems aside because they do not directly concern our topic. Our topic is the nature of our knowledge of objects in the following cases. We know that an object fits a definite description, though we have no direct acquaintance with any such object. This question concerns definite descriptions alone. From now on, therefore, I will simply say '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.

We will say that an object is 'known by description' when we know it is 'the so-and-so'. In other words, we know that exactly one object has a certain property. Usually, this also implies that we do not know the same object by acquaintance. We know that the man with the iron mask existed, and we know many facts about him. But we do not know who he was. We know that the candidate who gets the most votes will be elected. In this case, we are very likely also acquainted with the man who will actually get the most votes. Here, acquaintance means the only kind of acquaintance we can have with another person. But we do not know which candidate that man is. In other words, we know no statement of the form 'A is the candidate who will get most votes', where A names one of the candidates. We will say that we have 'merely descriptive knowledge' of the so-and-so under the following conditions. We know that the so-and-so exists. We may even be acquainted with the object that is, in fact, the so-and-so. Yet we know no statement of the form 'a is the so-and-so', where a is something we are acquainted with.

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.

When we say 'the so-and-so exists', we mean that exactly one object is the so-and-so. The statement 'a is the so-and-so' means that a has the property so-and-so, and nothing else does. '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 'someone is a Unionist candidate for this constituency, and no one else is'. So, when we are directly acquainted with an object that is the so-and-so, we know that the so-and-so exists. But we may know that the so-and-so exists without being directly acquainted with any object we know to be the so-and-so. We may even know this without being directly acquainted with any object that actually 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.

Ordinary words, even proper names, are usually descriptions in practice. When someone uses a proper name correctly, fully expressing their thought generally requires replacing the name with a description. Moreover, the description needed to express the thought will differ from person to person, or for one person over time. As long as the name is used correctly, only the object the name refers to stays the same. But as long as the object stays the same, the particular description usually makes no difference. The statement containing the name will still be true or false regardless of that description.

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.

Let us take some examples. Suppose someone makes a statement about Bismarck. Assume that a person can have direct acquaintance with themselves. Bismarck himself might then have used his name to refer directly to the particular person he was acquainted with. In that case, if he made a judgment about himself, Bismarck himself might be part of the judgment. Here the proper name has the direct use it always aims for. It simply stands for a particular object, not for a description of that object. But if someone who knew Bismarck made a judgment about him, the case would be different. That person was directly acquainted with certain sense-data, which he associated with Bismarck's body. We will suppose that this association was correct. Bismarck's body, as a physical object, was known only as the body associated with these sense-data. This was even more true of his mind, known only as the mind associated with these sense-data. In other words, both were known by description. Of course, chance largely determines which features of someone's appearance come to a friend's mind when thinking of that person. So the particular description in the friend's mind is a matter of chance. The essential point is that the friend knows the various descriptions all apply to the same entity. Yet the friend has no direct acquaintance with that entity.

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.

When those of us who did not know Bismarck make a judgment about him, we probably have a vague collection of historical knowledge in mind. In most cases, this knowledge goes far beyond what we need to identify him. But, for 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', in turn, will mean different things to different people. For some, the word will bring to mind travels in Germany. For others, it will recall Germany’s shape on a map, and so on. But to form a description we know applies, we must eventually refer to a particular thing we know directly. Any mention of the past, present, or future involves such a reference, unlike a definite date. So does any mention of here and there, or of what others have told us. Thus, a description known to apply to a particular thing must apparently refer somehow to something we know directly. This is necessary if our knowledge of the thing described goes beyond what follows logically from the description. For example, 'the most long-lived of men' is a description involving only universals, and it must apply to some man. But we can make no judgments about this man that involve knowledge beyond what the description provides. Suppose, however, we say, 'The first Chancellor of the German Empire was an astute diplomatist'. We can be sure this judgment is true only because of something we know directly, usually testimony heard or read. Set aside the information we convey to others. Set aside, too, the fact about the actual Bismarck that makes our judgment important. The thought we actually have contains the one or more particular things involved. Apart from those particular things, it consists entirely 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.

All place names, such as London, England, Europe, the Earth, and the Solar System, similarly involve descriptions when used. These descriptions start from one or more particular things we know directly. I suspect that even the Universe, as understood in metaphysics, involves such a connection with particular things. In logic, by contrast, we are concerned not only with what exists, but with whatever might or could exist or be. So logic involves no reference to actual particular things.

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.

When we make a statement about something known only by description, we often seem to intend something more. We want to speak about the actual thing described, rather than make a statement involving its description. For example, when we say something about Bismarck, we would like, if we could, to make a judgment only Bismarck can make. In that judgment, Bismarck himself would be a constituent. We necessarily fail, since we do not know the actual Bismarck directly. But we know there is an object B, called Bismarck, and that B was a shrewd diplomat. We can therefore describe the proposition we would like to affirm: 'B was a shrewd diplomat'. Here, B is the object that was Bismarck. Suppose we describe Bismarck as 'the first Chancellor of the German Empire'. We can then describe the proposition we would like to affirm as follows: 'the proposition stating that the actual object that was the first Chancellor of the German Empire was a shrewd diplomat'. We can communicate despite using different descriptions because we know there is a true proposition about the actual Bismarck. However we vary the description, as long as the description is correct, the proposition described remains the same. We are interested in this proposition, which we describe and know to be true. But we are not directly acquainted with the proposition itself. We do not know the proposition, 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.

There are several stages of distance from direct acquaintance with particulars. Consider Bismarck as known to people who knew him, then Bismarck as known to those who know him only through history. Next comes the man with the iron mask, and finally the longest-lived of men. Each example is further removed from acquaintance with particulars. The first comes as close to acquaintance as is possible when knowing another person. In the second, we would still be said to know 'who Bismarck was'. In the third, we do not know who the man with the iron mask was. But we can know many statements about him that do not follow logically from his wearing an iron mask. In the fourth, finally, we know nothing beyond what follows logically from the man's definition. There is a similar hierarchy among universals. Many universals, like many particulars, are known to us only by description. But here, as with particulars, knowledge about what we know by description ultimately reduces to knowledge about what we know 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.

The basic principle for analyzing propositions that contain descriptions is this: Every proposition we can understand must consist entirely of parts with which we are directly 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.

At this stage, we will not try to answer all the objections that may be raised against this fundamental principle. For now, we will simply point out that there must be some way to answer these objections. For it is hardly conceivable that we can judge or suppose anything without knowing what we are judging or supposing about. We must give some meaning to the words we use if we are to say something meaningful rather than merely make noise. And the meaning we give our words must be something we are acquainted with. So when, for example, we make a statement about Julius Caesar, Julius Caesar himself is clearly not before our minds. This is because we are not acquainted with him. We have some description of Julius Caesar in mind: '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 sound or shape we are acquainted with.) So our statement does not mean quite what it seems to mean. Instead of Julius Caesar himself, its meaning involves a description of him. That description consists entirely of particulars and universals we are acquainted with.

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.

Knowledge by description matters most because it lets us go beyond the limits of our private experience. We can only know truths made up entirely of terms we have encountered through direct acquaintance. Even so, we can know by description things we have never experienced. Since our immediate experience is so limited, this ability to know things by description is vital. Until we understand how such knowledge is possible, much of our knowledge must remain mysterious and therefore doubtful.