Philosophy of the Human Mind. 17 



till we come to its first constitution, which pro- 

 duces successively, and by necessary consequence, 

 every successive state throughout the whole course 

 of its existence/ 

 . This system, for many years after its publica- 

 tion, excited uncommon attention, and obtained 

 great currency, especially in the native country of 

 the author. It was early espoused by Carolus 

 Wolfius, a celebrated philosopher also of Ger- 

 many, a most voluminous commentator on the 

 writings of his master, and a zealous defender of 

 his doctrines. On the foundation of these doc- 

 trines he formed a new system of cosmology and 

 pneumatology, digested and demonstrated in a 

 mathematical method. The principles of Leib- 

 nitz had also some advocates, either in whole or 

 in part, in other parts of the continent of Europe, 

 and in Great-Britain, for a considerable time. But, 

 at the close of the eighteenth century, their reputa- 

 tion had much diminished, and they were adopted 

 by comparatively few, in any part of the philoso- 

 phical world. 



Among the great theorists in pneumatology 

 which belong to this period, Dr. Hartley, a ce- 

 lebrated English physician, also holds a conspi- 

 cuous place/ The two grand principles on which 

 his whole system rests, are those of Vibration and 

 Association. Newton had taught that the rays of 



j Reid's Intellectual Powers of Mar., Essay ii. 



k Dr. David Hartley was born in Yorkshire, August 30, 1705, and 

 died at Bath, August 28, I7J7-. His great work, the Observations on Man, 

 was published in 1749. He was educated with a view to the clerical pro- 

 fession, in the Church of England; but feeling some scruples about sub- 

 scribing to the thirty-nine articles, he relinquished that design, and devoted 

 himself to the study and practice of medicine, in which he was eminent. 

 While he departed from the public standards of his church in several im- 

 portant particulars, he was much distinguished for the force of his mind, 

 the extent of his learning, the amiableness and benevolence of his dispo- 

 sition, and the purity of his moral character. He was a firm believer in 

 Revelation, and wrote, though not with orthodoxy, yet with great scrioui- 

 ness and ability in its defence. 



VOL. II, D 



