since they are based upon correlations which are usual but not
invariable. Any such correlation may mislead us in a particular case,
for example, if we try to touch a reflection in a looking-glass under
the impression that it is "real." Since memory is fallible, a similar
difficulty arises as regards consciousness of past objects. It would
seem odd to say that we can be "conscious" of a thing which does not or
did not exist. The only way to avoid this awkwardness is to add to our
definition the proviso that the beliefs involved in consciousness must
be TRUE.

In the second place, the question arises as to whether we can be
conscious of images. If we apply our definition to this case, it seems
to demand images of images. In order, for example, to be conscious of
an image of a cat, we shall require, according to the letter of the
definition, an image which is a copy of our image of the cat, and has
this image for its prototype. Now, it hardly seems probable, as a matter
of observation, that there are images of images, as opposed to images
of sensations. We may meet this difficulty in two ways, either by boldly
denying consciousness of images, or by finding a sense in which, by
means of a different accompanying belief, an image, instead of meaning
its prototype, can mean another image of the same prototype.

The first alternative, which denies consciousness of images, has already
been discussed when we were dealing with Introspection in Lecture VI. We
then decided that there must be, in some sense, consciousness of images.
We are therefore left with the second suggested way of dealing with
knowledge of images. According to this second hypothesis, there may be
two images of the same prototype, such that one of them means the other,
instead of meaning the prototype. It will be remembered that we defined
meaning by association a word or image means an object, we said, when it
has the same associations as the object. But this definition must not be
interpreted too absolutely: a word or image will not have ALL the
same associations as the object which it means. The word "cat" may
be associated with the word "mat," but it would not happen except by
accident that a cat would be associated with a mat. And in like manner
an image may have certain associations which its prototype will not
have, e.g. an association with the word "image." When these associations
are active, an image means an image, instead of meaning its prototype.
I