There is certainly no profounder emotional excitement during sleep than that which arises from a disturbed or distended stomach, and is reflected by the pneumogastric to the accelerated heart and the excited respiration.[88] We are thereby thrown into a state of emotional agitation, a state of agony and terror, such as we rarely or never attain during waking life. Sleeping consciousness, blindfolded and blundering, a prey to these massive waves from below, and fumbling about desperately for some explanation, jumps at the idea that only the attempt to escape some terrible danger or the guilty consciousness of some awful crime can account for this immense emotional uproar. Thus the dream is suffused by a conviction which the continued emotion serves to support. We do not--it seems most simple and reasonable to conclude--experience terror because we think we have committed a crime, but we think we have committed a crime because we experience terror. And the fact that in such dreams we are far more concerned with escape from the results of crime than with any agony of remorse is not, as some have thought, due to our innate indifference to crime, but simply to the fact that our emotional state suggests to us active escape from danger rather than the more passive grief of remorse. Thus our dreams bear witness to the fact that our intelligence is often but a tool in the hands of our emotions.[89] In this tendency, it may be noted, we see the basis of the symbolism which plays so real a part in dreams. Such symbolism rests on the fact that we associate two things--even if the one happens to be physical and the other spiritual--which both happen to imply a similar state of feeling.[90] Symbolism of this kind is, indeed, characteristic of the human mind at all times, in all stages of its development. Thus the physical idea of _height_ seems to express also a moral idea, which we feel to be correspondent, while wormwood and gall furnish a taste which enabled men to speak of what seemed to them the corresponding _bitterness_ of death. In dreams this natural tendency of the mind is able to work unchecked and extravagantly. It acts with much facility on any impulse arising from the gastric region, because this region is the seat of various sensations and emotions, both physical and moral, which may thus act symbolically the one for the other.[91]