HOW TO SLEEP 



of the individual are by no means to be judged as a rule 

 from his customs. A man may habitually sleep two 

 or three hours longer than is necessary simply because 

 he has acquired what I may term slovenly habits of 

 sleeping. The penalty for such indulgence is not only 

 loss of time, but defective sleep, into which conscious- 

 ness constantly tends to enter. Although the brain 

 probably never becomes absolutely quiescent, and al- 

 though in consequence all sleep must be regarded as 

 theoretically a dream-state, yet it is certain that in pro- 

 found natural slumber the energy of the brain is at 

 such an ebb tide that its functionings do not rise to the 

 level even of subconsciousness. Profound perfectly nat- 

 ural slumber is to the awakened consciousness merely a 

 period of absolute blank. The energy of mind has 

 simply sunk below the level of consciousness, and, in 

 the nature of the case, while it remains below that 

 level there can be no conscious record of its opera- 

 tions. Experience has shown that in normal sleep the 

 neural energy (whose psychic counterpart is mind) con- 

 tinues to sink to yet lower levels from one to two hours 

 after consciousness is lost. Slumber is then most pro- 

 found. From this point the potential energy gradually 

 increases, like an inflowing tide, slumber becoming 

 less and less profound, until finally the level of conscious- 

 ness is reached, and the sleeper awakens. 



That consciousness is really farther withdrawn, if 

 I may be permitted the expression, during the period 

 of deepest sleep than before or after this period admits 

 of no question. A sleeper is awakened at such a time 

 with relative difficulty, and on awakening he is apt to 



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