MAURY ON SLEEP AND DREAMS. 375 



that concerns personal identity the Ego of the dif- 

 ferent stages and states of our being has been under 

 the dominion of unsettled terms in all ages of philo- 

 sophy. Words have not inaptly been called ' the 

 counters of wise men, and the money of fools.' But 

 even the wisest have been unwittingly governed by 

 them in questions thus obscure or insoluble. 



Quitting, however, this region of hypothesis, we 

 willingly come to the more practical part of the sub- 

 jectthat which we learn from observation and expe- 

 rience regarding these phenomena. Here we must 

 again mention the liabilities to error, which occur even 

 in the simplest form of such investigation. Besides 

 those already noticed, we find another in the un- 

 doubted diversity of the phenomena in different indi- 

 viduals. The writer on sleep and dreams is not 

 entitled to repose on his own experience only. A 

 dozen persons would probably give as many different 

 versions of their particular consciousness in the matter ; 

 and it is not easy to draw averages from these fleeting 

 shadows of the night. They change with age, and 

 other conditions of life, moral and intellectual, which 

 govern sleep and the dreams associated with it. The 

 simple, but touching lines, 



' Thou hast been called, Sleep, the friend of woe, 

 But 'tis the happy who have called thee so,' 



point at one familiar source of this diversity, but there 

 are many others, of which we shall speak hereafter. 



In prosecuting the subject, we must first refer 

 again to Sleep in its general sense, as the function of 



