Not only is that association absurd but its consequences are regrettable, at least from one point of view: if sleep is a form of death, the psychic phenomena connected with it are bound to be misinterpreted and either granted a dignity they do not deserve or scornfully ignored.
The superstitious may loose all critical sense and see in sleep and sleep thinking something mysterious and mystical. The scientist, on the other hand, may consider such phenomena as beneath his notice.
No sober appreciation of sleep and dreams can be expected from any one who associates in any way the idea of sleep and the idea of death.
Respiration seems to be the essential feature of life, and its lack, the essential feature of death. As long as respiration takes place, the two ferments of the body, pepsin and trypsin, break up insoluble food molecules into soluble acid molecules which are then absorbed by the blood and carried to the cells of the body where they are utilized to build up new solid cell matter.
When respiration ceases, a degree of acidity is reached which enables the two ferments to digest the body of disintegrating each cell. This is according to Jacques Loeb the meaning of death.
No such chemical action is observable in any form of sleep.
From that point of view, sleep is a form of life.
Sleep is even a more normal form of life than the average waking states.
In the normal waking states, the vagotonic nerves of the autonomic system which upbuild the body and insure the continuance of the race should dominate the organism, being checked in emergencies only by the sympathetic nerves which constitute the human safety system.
The vagotonic nerves contract the pupil, make saliva and gastric juice flow, slow down the heart beats, decrease the blood pressure, promote sexual activities, etc.