ents will show that such is veritably the case, and that our two
most trustworthy senses may be made to contradict one another on this
very point. Hold the marble between the finger and thumb, and look at it
in the ordinary way. Sight and touch agree that it is single. Now
squint, and sight tells you that there are two marbles, while touch
asserts that there is only one. Next, return the eyes to their natural
position, and, having crossed the forefinger and the middle finger, put
the marble between their tips. Then touch will declare that there are
two marbles, while sight says that there is only one; and touch claims
our belief, when we attend to it, just as imperatively as sight does.

But it may be said, the marble takes up a certain space which could not
be occupied, at the same time, by anything else. In other words, the
marble has the primary quality of matter, extension. Surely this quality
must be in the thing, and not in our minds? But the reply must still be;
whatever may, or may not, exist in the thing, all that we can know of
these qualities is a state of consciousness. What we call extension is a
consciousness of a relation between two, or more, affections of the
sense of sight, or of touch. And it is wholly inconceivable that what
we call extension should exist independently of such consciousness as
our own. Whether, notwithstanding this inconceivability, it does so
exist, or not, is a point on which I offer no opinion.

Thus, whatever our marble may be in itself, all that we can know of it
is under the shape of a bundle of our own consciousnesses.

Nor is our knowledge of anything we know or feel more, or less, than a
knowledge of states of consciousness. And our whole life is made up of
such states. Some of these states we refer to a cause we call "self;"
others to a cause or causes which may be comprehended under the title of
"not-self." But neither of the existence of "self," nor of that of
"not-self," have we, or can we by any possibility have, any such
unquestionable and immediate certainty as we have of the states of
consciousness which we consider to be their effects. They are not
immediately observed facts, but results of the application of the law of
causation to those facts. Strictly speaking, the existence of a "self"
and of a "not-self" are hypotheses by which we account for the facts of
consciousness. They stand upon the same footing as the belief in the
general trustworthiness of memory, an