328 LECTURE VII. 



think, it is difficult to determine, because 

 they do not explicitly declare their senti- 

 ments. There is a mysticism in their ex- 

 pressions and manner, calculated to delude 

 the ignorant, and perplex those who have 

 not fully considered the subjects under dis- 

 cussion. Therefore, it seemed right to place 

 distinctly before you, in the first lectures 

 of this year, the only opinions which the 

 mind of man is capable of entertaining, re- 

 lative to the causes of motion in matter. In 

 exploring the cause of the contrary states 

 of motion and rest, the mind's eye alter- 

 nately dimmed and dazzled, becomes weary 

 and confused, and ceasing from the fruitless 

 search, fixes itself upon a partial view of 

 the subject, which it thinks it has obtained. 

 We feel a strong conviction, that a more 

 subtile and mobile substance, or a more 

 attenuated species of matter pervades, acts 

 upon, and is the cause of motion in that 

 which is more gross and inert. 



Who can observe the seemingly vita} 

 effects which the warmth of the sun pro- 

 duces, even in common matter, or the terrific 



