consciousness of any one of these component elements of a complex
brings with it all the rest_.

[Sidenote: _Bodily Effects of Ideas_]

For example, the ideas pertaining to any terrifying experience, when
recalled to consciousness, bring with them the trembling, the wildly
beating heart, the shaking knees, with which they were originally
accompanied. The victim of stage-fright feels his knees give way and
that he is sinking to the floor; his heart beats tumultuously, cold
perspiration covers his body, he blushes, his mouth is dry, and his
voice sticks in his throat. Afterwards, alone in his own room, the
memory of that dreadful moment, the thought of another appearance
before that audience, will be accompanied by the same physiological
effects.

[Sidenote: _Impulses and Inhibitions_]

Every such bodily movement is an expression of energy. The recall to
consciousness of the terrifying experience, the recall of the picture
of the assembled audience, these things automatically produce bodily
activities. So we must conclude that _Every idea in memory has
associated with it the potential energy necessary for the production
of muscular movement_.

It does not necessarily follow that the recall to consciousness of a
given idea will be invariably followed by an outwardly visible
muscular activity expressive of its energy. Just as the mere presence
of an idea in consciousness tends to bring about a movement, so _the
presence of a contrary idea will tend to inhibit it_.