OF SLEEP. SECT, XVIII. 13. 14, 



jof time or place, they would have taken up, had 

 they real exiftence ; and that more frequently than 

 in our waking hours ; and hence the time appears 

 longer to us : and I make no doubt, but the per- 

 mitted time appears long to a man .going to the gal- 

 lows, as the fear of its quick lapfe will make him 

 think frequently about tit, 



13. As we gain our knowledge of time by com- 

 paring the prefent fcenery with the pad and future, 

 and of place by comparing the fituations of objects 

 with each other ; fo we gain our idea of confciouf- 

 nefs by comparing ourfelves with the fcenery around 

 us ; and of identity by comparing our prefent con- 

 fcioufnefs with our pad confcioufnefs : as we never 

 think of time or place, but when we make the com- 

 parifpus above mentioned, fo we never think of con- 

 icioufnefs, but when we compare our own exiftence 

 with that of other objects ; nor of identity, but 

 when we compare our prefent and our paft confei- 

 oufnefs. Hence the confcioufnefs of our own ex- 

 iftence, and of pur identity, is owing to a voluntary- 

 exertion of our minds : and OQ that account in our 

 complete dreams we neither meafure time, are fur- 

 prifed at the fudden changes of place, 'nor attend to 

 our own exiftence, or identity; becaufe our power 

 of volition is fufpended. B,ut all thefe circumftances 

 are more or lefs obfervable in our incomplete ones ; 

 for then we attend a little to the lapfe of time, and 

 the changes of place, and to our pwrj exiftence ; and 

 even to our identity of perfon ; for a lady feldom, 

 dreams, that (he is a foidier ; nor a man, that he i 

 brought to bed. 



14. As long as our fenfations only excite theii; 

 fenfual motions, or ideas, our ileep continues found ; 

 but as foon as they excite defires or averfions, our 

 fleep becomes imperfect ; and when that defire or 

 averfion is fo ftrong, as to produce voluntary mo- 

 tions. 



