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 roused 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. Leibniz
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.


CHAPTER II
THE EXISTENCE OF MATTER

In this chapter we have to ask ourselves whether, in any sense at all,
there is such a thing as matter. Is there a table which has a certain