Conjectures on the proximate Cause of Sleep. 253 



Hartley seems also but little inclined to attribute these phae- 

 iiomeua alone to the soul. His views, as far as they go, are clear 

 and satisfactory. " Dreams (1^ says) are nothing more but the 

 imaginations, fancies or reveries of a sleeping man ; and they 

 are deducible from the three following causes : 1st, The impres- 

 sions and ideas lately received, and particularly those of the pre- 

 ceding day. 2d, The state of the body, particularly the siomack 

 and brain. Jid, Association *." " The scenes which present 

 themselves are taken to be real, we do not consider them as the 

 Avork of the fancy ; but suppose ourselves present and actually 

 seeing and hearing what passes. Now this happens, because we 

 have no other reality to oppose to the ideas which offer them- 

 selves : whereas, in the common fictions of the fancy, while we 

 are awake, there is always a set of real external objects striking 

 some of our senses, and precluding a like mistake there : or, if 

 ■we come quite inattentive to external objects, the reverie does so 

 far put on the nature of a dream as to appear a realityf ." 



Beattie appears to have entertained a very confused idea of the 

 nature of the soul, and even to have conceived that some of her 

 faculties fall asleep while others remain awake. He does not, 

 lionvever, exclude the influence altogether of the corporeal organs. 

 *' The imagination or fancy (he remarks) seems to be almost the 

 only one of our mental powers which is never suspended in its 

 operations bv sleep ; of the other faculties, some are more and 

 others less affected, and some appear to be for a time wholly ex- 

 tinguished J." " Persons (he continues) who think much and 

 take little bodily exercise, will, perhaps, be found to be the 

 greatest dreamers ; especially, if their imagination be active, and 

 their nervous system very delicate §." 



Darwin's doctrine is also connected with corporeal relations, 

 as may be found in his observation, that the " perpetual flow of 

 the trains of ideas which constitute our dreams, and which are 

 caused by painful or pleasurable sensation, might at first view be 

 conceived to be an useless expenditure of sensorial power ||." 

 We at least learn that, in his opinion, they really occur during 

 an accumulation of this power, when he adds, that " our dreams 

 in the morning have greater variety and vivacity, as our sensibility 

 increases, than at night when we first lie down H." But this hy- 

 pothesis is not less vague, though apparently more philosophic, 

 than the exploded systems of the nervous fluid and animal spirits. 

 The sensorial power is in fact the nervous fluid stripped of its 

 substance and reality, and reduced to a quality or attribute. 



• Hartley on M^n, quarto, p. 22G. t ''J- P- "7- 



X Beattie's Dissertations, moral and critical, vol. 1, p. -7-- 

 § Id. p. 271. II Zoonomia, London 1801, vol. I, p. 287- 



^ Id. p. ^302. 



Professor 



