ognizable. Even in the case of familiar external impressions, such as
the sound of the striking of a clock, there appears to be wanting that
simple process of reaction by which, in a waking condition of the
attention, a sense-impression is instantly discriminated and classed. In
sleep, as in the artificially induced hypnotic condition, the slighter
differences of quality among sensations are not clearly recognized. The
activity of the higher centres, which are concerned in the finer
processes of discrimination and classification, being greatly reduced,
the impression may be said to come before consciousness as something
novel and unfamiliar. And just as we saw that in waking life novel
sensations agitate the mind, and so lead to an exaggerated mode of
interpretation; so here we see that what is unfamiliar disturbs the
mind, rendering it incapable of calm attention and just interpretation.

This failure to recognize the real nature of an impression is seen most
conspicuously in the case of the organic sensations. As I have remarked,
these constitute for the most part, in waking life, an undiscriminated
mass of obscure feeling, of which we are only conscious as the mental
tone of the hour. And in the few instances in which we do attend to them
separately, whether through their exceptional intensity or in
consequence of an extraordinary effort of discriminative attention, we
can only be said to perceive them, that is, recognize their local
origin, very vaguely. Hence, when asleep, these sensations get very
oddly misinterpreted.

The localization of a bodily sensation in waking life means the
combination of a tactual and a visual image with the sensation. Thus, my
recognition of a twinge of toothache as coming from a certain tooth,
involves representations of the active and passive sensations which
touching and looking at the tooth would yield me. That is to say, the
feeling instantly calls up a compound mental image exactly answering to
a visual percept. This holds good in dream-interpretation too; the
interpretation is effected by means of a visual image. But since the
feeling is only very vaguely recognized, this visual image does not
answer to the bodily part concerned. Instead of this, the fancy of the
dreamer constructs some visual image which bears a vague resemblance to
the proper one, and is generally, if not always, an exaggeration of this
in point of extensive magnitude, etc. For example, a sensation arising
fro