always conscious whenever they happen.

* Cf. Lecture VI.

The first thing to notice is that consciousness must be of something. In
view of this, I should define "consciousness" in terms of that relation
of an image of a word to an object which we defined, in Lecture XI, as
"meaning." When a sensation is followed by an image which is a "copy" of
it, I think it may be said that the existence of the image constitutes
consciousness of the sensation, provided it is accompanied by that sort
of belief which, when we reflect upon it, makes us feel that the image
is a "sign" of something other than itself. This is the sort of belief
which, in the case of memory, we expressed in the words "this occurred";
or which, in the case of a judgment of perception, makes us believe
in qualities correlated with present sensations, as e.g., tactile and
visual qualities are correlated. The addition of some element of belief
seems required, since mere imagination does not involve consciousness of
anything, and there can be no consciousness which is not of something.
If images alone constituted consciousness of their prototypes,
such imagination-images as in fact have prototypes would involve
consciousness of them; since this is not the case, an element of belief
must be added to the images in defining consciousness. The belief must
be of that sort that constitutes objective reference, past or
present. An image, together with a belief of this sort concerning it,
constitutes, according to our definition, consciousness of the prototype
of the image.

But when we pass from consciousness of sensations to consciousness of
objects of perception, certain further points arise which demand an
addition to our definition. A judgment of perception, we may say,
consists of a core of sensation, together with associated images, with
belief in the present existence of an object to which sensation and
images are referred in a way which is difficult to analyse. Perhaps we
might say that the belief is not fundamentally in any PRESENT existence,
but is of the nature of an expectation: for example, when we see an
object, we expect certain sensations to result if we proceed to touch
it. Perception, then, will consist of a present sensation together with
expectations of future sensations. (This, of course, is a reflective
analysis, not an account of the way perception appears to unchecked
introspection.) But all such expectations are liable to be erroneous,