The Problems of Philosophy | Page 3

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 that 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 rapping 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 colours, 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 colour, we have a sensation
of the colour, but the colour itself is a sense-datum, not a sensation. The colour 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
colour, 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 re-stated 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 Hylas and Philonous, in Opposition to
Sceptics 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. Hylas has hitherto believed
in matter, but he is no match for Philonous, 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 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