menu_book Chapter 9

is there any knowledge in the world which is so certain that no reasonable man could doubt it this question which at first sight might not seem difficult is really one of the most difficult that can be asked when we have realized the obstacles in the way of a straightforward and confident answer we shall be well launched on the study of philosophy for philosophy is merely the attempt to answer such ultimate questions not carelessly and dogmatically as we do in ordinary life and even in the sciences but critically after exploring all that makes such questions puzzling and after realizing all the vagueness and confusion that underlie our ordinary ideas in daily life we assume as certain many things which on a closer scrutiny are found to be so full of apparent contradictions that only a great amount of thought enables us to know what it is that we really may believe in the search for certainty it is natural to begin with our present experiences and in some sense no doubt knowledge is to be derived from them

but any statement as to what it is that our immediate experiences make us know is very likely to be wrong it seems to me that i am now sitting in a chair at a table of a certain shape on which i see sheets of paper with writing or print by turning my head i see out the window buildings and clouds and the sun i believe that the sun is about ninety three million miles from the earth that it is a hot globe many times bigger than the earth that owing to the earth's rotation it rises every morning and will continue to do so for an indefinite time in the future i believe that if any other normal person comes into my room he will see the same chairs and tables and books and papers as i see and that the table which i see is the same as the table which i feel pressing against my arm all this seems to be so evident as to be hardly worth stating except in answer to a man who doubts whether i know anything yet all this may be reasonably doubted and all of it requires much careful discussion before we can be sure that we have stated it

in a form that is wholly true to make our difficulties plain let us concentrate attention on the table to the eye it is oblong brown and shiny to the touch it is smooth and cool and hard when i tap it it gives out a wooden sound any one else who sees and feels and hears the table will agree with this description so that it might seem as if no difficulty would arise but as soon as we try to be more precise our troubles begin although i believe that the table is really of the same colour all over the parts that reflect the light look much brighter than the other parts and some parts look white because of reflected light i know that if i move the parts that reflect the light will be different so that the apparent distribution of colours on the table will change it follows that if several people are looking at the table at the same moment no two of them will see exactly the same distribution of colours because no two can see it from exactly the same point of view and any change in the point of view makes some change in the way the light is reflected for most practical purposes these differences are unimportant but to the painter they are all important the painter has to unlearn the habit of thinking that things seem to have the colour which common sense says they really have and to learn the habit of seeing things as they appear

here we have already the beginning of the distinctions that cause most trouble in philosophy the distinction between appearance and reality between what things seem to be and what they are the painter wants to know what things seem to be the practical man and the philosopher want to know what they are but the philosophers wish to know this is stronger than the practical man's and is more troubled by knowledge as to the difficulties of answering the question to return to the table it is evident from what we have found that there is no colour which pre-eminently appears to be the colour of the table or even of one particular part of the table it appears to be of different colours from different points of view and there is no reason for regarding some of these as more really its colour than others and we know that that even from a given point of view the colour will seem different by artificial light or to a colour blind man or to a man wearing blue spectacles while in the dark there will be no colour at all though to touch and hearing the table will be unchanged the colour is not something which is inherent in the table but something depending upon the table and the spectator and the way the light falls on the table when in ordinary life we speak of the colour of the table we only mean the sort of colour which it will seem to have to a normal spectator from an ordinary point of view under usual conditions of light but the other colours which appear under other conditions have just as good a right to be considered real and therefore to avoid favouritism we are compelled to deny that in itself the table has any one particular colour

the same thing applies to the texture with the texture with the naked eye one can see the grain but otherwise the table looks smooth and even if we looked at it through a microscope we should see roughnesses and hills and valleys and all sorts of differences that are imperceptible to the naked eye which of these is the real table we are naturally tempted to say that what we see through the microscope is more real but that in turn would be changed by a still more powerful microscope if then we cannot trust what we see through a microscope thus again the confidence in our senses with which we began deserts us the shape of the table is no better we are all in the habit of judging as to the real shapes of things and we do this so unreflectingly that we come to think we actually see the real shapes but in fact as we all have to learn how to be in one of judging as to the real shapes of things, and we do this so unreflectingly

that we come to think we actually see the real shapes. But in fact, as we all have to learn, if we try to draw, a given thing looks different in shape from every different point of view.

If our table is really rectangular, it will look, from almost all points of view, as if it had two acute angles and two obtuse angles, if opposite sides are parallel, they will look as if they converge to a point

away from the spectator. If they are of equal length, they will look as if the nearer side were longer. All these things are not commonly noticed in looking at a table,

because experience has taught us to construct the real shape from the apparent shape, and the real shape is what interests us as practical men. But the real shape is not what we see. It is something inferred from what we see.

And what we see is constantly changing in shape as we move about the room, so that here, again, the senses seem not to give us the truth about the table itself,

but only about the appearance of the table. Similar difficulties arise when we consider the sense of touch. It is true that the table always gives us a sensation of hardness,

and we feel it resists pressure. But the sensation we obtain depends upon how hard we press the table, and also upon what part of the body we press with.

Thus, the various sensations, due to various pressures, or various parts of the body, cannot be supposed to reveal, directly,

any definite property of the table, but at most to be signs of some property, which perhaps causes all the sensations, but is not actually apparent in any of them.

And the same applies, still more obviously, to the sounds which can be elicited by wrapping the table. Thus it becomes evident

that the real table, if there is one, is not the same as what we immediately experience by sight or touch or hearing. The real table,

if there is one, is not immediately known to us at all, but must be an inference from what is immediately known. Hence,

two very difficult questions at once arise. Namely, 1. Is there a real table at all? 2.

If so, what sort of object can it be? It will help us in considering these questions to have a few simple terms of which the meaning is definite and clear.

Let us give the name of sense data to the things that are immediately known in sensation, such things as colors, sounds, smells,

hardnesses, roughnesses, and so on. We shall give the name sensation to the experience of being

immediately aware of these things. Thus, whenever we see a color, we have a sensation of the color, but the color itself

is a sense datum, not a sensation. The color is that of which we are immediately aware, and the awareness itself

is the sensation. It is plain that if we are to know anything about the table, it must be by means of the sense data, brown color,

oblong shape, smoothness, etc., which we associate with the table. But,

for the reasons which have been given, we cannot say that the table is the sense data, or even that the sense data are directly properties

of the table. Thus, a problem arises as to the relation of the sense data

to the real table, supposing there is such a thing. The real table, if it exists, we will call

a physical object. Thus, we have to consider the relation of sense data to physical objects.

The collection of all physical objects is called matter. Thus, our two questions

may be restated as follows. 1. Is there any such thing as matter? 2.

If so, what is its nature? The philosopher who first brought prominently forward the reasons

for regarding the immediate objects of our senses as not existing independently of us

was Bishop Berkeley, 1685-1753. His Three Dialogues Between Hylus

and Philonus in Opposition to Skeptics and Atheists undertake to prove

that there is no such thing as matter at all, and that the world consists of nothing but minds

and their ideas. Hylus has hitherto believed in matter, but he is no match

for Philonus, who mercilessly drives him into contradictions and paradoxes,

and makes his own denial of matter seem, in the end, as if it were almost common sense.

The arguments employed are of very different value. Some are important and sound, others are confused

or quibbling. But Berkeley retains the merit of having shown that the existence

of matter is capable of being denied without absurdity, and that

that if there are any things that exist independently of us, they cannot be

the immediate objects of our sensations. There are two different questions involved when we ask

whether matter exists, and it is important to keep them clear. We commonly mean by matter

something which is opposed to mind, something which we think of as occupying space

and as radically incapable of any sort of thought or consciousness. It is chiefly

in this sense that Berkeley denies matter. That is to say, he does not deny

that the sense data, which we commonly take as signs of the existence of the table,

are really signs of the existence of something independent of us, but he does deny

that this something is non-mental, that it is neither mind nor ideas

entertained by some mind. He admits that there must be something

which continues to exist when we go out of the room or shut our eyes,

and that what we call seeing the table does really give us reason for believing in something

which persists even when we are not seeing it. But, he thinks that

this something cannot be radically different in nature from what we see, and cannot be

independent of seeing altogether, though it must be independent of our seeing.

He is thus led to regard the real table as an idea in the mind

of God. Such an idea has the required permanence and independence

of ourselves without being, as matter would otherwise be, something quite

unknowable, in the sense that we can only infer it, and can never be

directly and immediately aware of it. Other philosophers since Berkeley

have also held that, although the table does not depend for its existence

upon being seen by me, it does depend on being seen, or otherwise

apprehended in sensation, by some mind, not necessarily the mind of God, but more often

the whole collective mind of the universe. This they hold, as Berkeley does, chiefly because

they think there can be nothing real, or at any rate nothing known

to be real except minds and their thoughts and feelings. We might state

the argument by which they support their view in some such way as this,

whatever can be thought of is an idea in the mind of the person

thinking of it, therefore nothing can be thought of except ideas in minds,

therefore anything else is inconceivable, and what is inconceivable cannot exist.

Such an argument, in my opinion, is fallacious, and of course those who advance

it do not put it so shortly or so crudely. But whether valid or not,

the argument has been very widely advanced in one form or another,

and very many philosophers, perhaps a majority, have held that there is nothing

real except minds and their ideas. Such philosophers are called idealists.

When they come to explaining matter, they either say, like Berkeley,

that matter is really nothing but a collection of ideas. Or they say,

like Liebnis, 1646-1716, that what appears as matter is really a collection

of more or less rudimentary minds. But these philosophers, though they deny matter as opposed

to mind, nevertheless, in another sense, admit matter. It will be remembered

that we asked two questions, namely, one, is there a real

table at all? Two, if so, what sort of object can it be?

Now, both Berkeley and Liebnis admit that there is

a real table, but Berkeley says it is certain ideas in the mind of God, and Liebnis

says it is a colony of souls. Thus, both of them

answer our first question in the affirmative, and only diverge from the views

of ordinary mortals in their answer to our second question. In fact, almost all philosophers

seem to be agreed that there is a real table. They almost all agree that,

however much our sense data, color, shape, smoothness,

etc., may depend upon us, yet their occurrence is a sign of something existing

independently of us, something differing, perhaps, completely from our sense data,

and yet to be regarded as causing those sense data whenever we are

in a suitable relation to the real table. Now, obviously,

this point in which the philosophers are agreed, the view that there is

a real table, whatever its nature may be, is vitally important,

and it will be worthwhile to consider what reasons there are for accepting

this view before we go on to the further question as to the nature of

the real table. Our next chapter, therefore, will be concerned with the reasons

for supposing that there is a real table at all. Before we go farther,

it will be well to consider for a moment what it is that we have discovered so far. it has appeared that

if we take any common object of the sort that is supposed to be known by the

senses, what the senses immediately tell us is not the truth about the object

as it is apart from us, but only the truth about certain sense data which,

so far as we can see, depend upon the relations between us and the object.

Thus, what we directly see and feel is merely appearance, which we believe

to be a sign of some reality behind. But if the reality is not what appears,

have we any means of knowing whether there is any reality at all? And if so,

have we any means of finding out what it is like? Such questions are bewildering,

and it is difficult to know that even the strangest hypotheses may not be true.

Thus, our familiar table, which has aroused but the slightest thoughts in us

hitherto, has become a problem full of surprising possibilities. The one thing

we know about it is that it is not what it seems. Beyond this modest result,

so far, we have the most complete liberty of conjecture. Libnese tells us

it is a community of souls. Berkeley tells us it is an idea in the mind of God.

Sober science, scarcely less wonderful, tells us it is a vast collection of electric charges

in violent motion. Among these surprising possibilities, doubt suggests that perhaps

there is no table at all. Philosophy, if it cannot answer so many questions

as we could wish, has at least the power of asking questions, which increase

the interest of the world and show the strangeness and wonder lying just below

the surface, even in the commonest things of daily life. End of

Appearance and Reality by Bertrand Russell