minds that can be
thus known immediately. What goes on in the minds of others is known
to us through our perception of their bodies, that is, through the
sense-data in us which are associated with their bodies. But for our
acquaintance with the contents of our own minds, we should be unable to
imagine the minds of others, and therefore we could never arrive at
the knowledge that they have minds. It seems natural to suppose that
self-consciousness is one of the things that distinguish men from
animals: animals, we may suppose, though they have acquaintance with
sense-data, never become aware of this acquaintance. I do not mean
that they _doubt_ whether they exist, but that they have never become
conscious of the fact that they have sensations and feelings, nor
therefore of the fact that they, the subjects of their sensations and
feelings, exist.

We have spoken of acquaintance with the contents of our minds as
_self_-consciousness, but it is not, of course, consciousness of our
_self_: it is consciousness of particular thoughts and feelings. The
question whether we are also acquainted with our bare selves, as opposed
to particular thoughts and feelings, is a very difficult one, upon which
it would be rash to speak positively. When we try to look into ourselves
we always seem to come upon some particular thought or feeling, and not
upon the 'I' which has the thought or feeling. Nevertheless there are
some reasons for thinking that we are acquainted with the 'I', though
the acquaintance is hard to disentangle from other things. To make clear
what sort of reason there is, let us consider for a moment what our
acquaintance with particular thoughts really involves.

When I am acquainted with 'my seeing the sun', it seems plain that I am
acquainted with two different things in relation to each other. On the
one hand there is the sense-datum which represents the sun to me, on the
other hand there is that which sees this sense-datum. All acquaintance,
such as my acquaintance with the sense-datum which represents the sun,
seems obviously a relation between the person acquainted and the object
with which the person is acquainted. When a case of acquaintance is one
with which I can be acquainted (as I am acquainted with my acquaintance
with the sense-datum representing the sun), it is plain that the person
acquainted is myself. Thus, when I am acquainted with my
seeing the sun, the whole fact with which I am acquainted is
'Self-