us and our senses. And very
similar remarks would apply to other kinds of sensations.

It is not only colours and sounds and so on that are absent from the
scientific world of matter, but also _space_ as we get it through sight
or touch. It is essential to science that its matter should be in _a_
space, but the space in which it is cannot be exactly the space we see
or feel. To begin with, space as we see it is not the same as space as
we get it by the sense of touch; it is only by experience in infancy
that we learn how to touch things we see, or how to get a sight of
things which we feel touching us. But the space of science is neutral as
between touch and sight; thus it cannot be either the space of touch or
the space of sight.

Again, different people see the same object as of different shapes,
according to their point of view. A circular coin, for example, though
we should always _judge_ it to be circular, will _look_ oval unless we
are straight in front of it. When we judge that it _is_ circular, we are
judging that it has a real shape which is not its apparent shape, but
belongs to it intrinsically apart from its appearance. But this real
shape, which is what concerns science, must be in a real space, not
the same as anybody's _apparent_ space. The real space is public, the
apparent space is private to the percipient. In different people's
_private_ spaces the same object seems to have different shapes; thus
the real space, in which it has its real shape, must be different from
the private spaces. The space of science, therefore, though _connected_
with the spaces we see and feel, is not identical with them, and the
manner of its connexion requires investigation.

We agreed provisionally that physical objects cannot be quite like
our sense-data, but may be regarded as _causing_ our sensations.
These physical objects are in the space of science, which we may call
'physical' space. It is important to notice that, if our sensations
are to be caused by physical objects, there must be a physical space
containing these objects and our sense-organs and nerves and brain. We
get a sensation of touch from an object when we are in contact with it;
that is to say, when some part of our body occupies a place in physical
space quite close to the space occupied by the object. We see an object
(roughly speaking) when no opaque body is between the object and our
eyes in physical space. Similarly, we only hear or smell or taste