which we are 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.

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.

CHAPTER VI. ON INDUCTION

In almost all our previous discussions we have been concerned in
the attempt to get clear as to our data in the way of knowledge of
existence. What things are there in the universe whose existence is
known to us owing to our being acquainted with them? So far, our answer
has been that we are acquainted with our sense-data, and, probably,
with ourselves. These we know to exist. And past sense-data which
are remembered are known to have existed in the past. This knowledge
supplies our data.

But if we are to be able to draw inferences from these data--if we are
to know of the existence of matter, of