■408 Analogy lehreeJi Man mid the Brute Creation, 



tion, and is the inevitable effect of a certain law. Mind 

 can only be produced by ibe operation of a tirst cause, 

 wliich cause is an all-powerful Deity : but it is siirtly as 

 easy for him to impart certain powers and faculties to one 

 substance as to another; and to make that substance indi- 

 visible, incorruptible, and immonal. From the universal use 

 of 'blockhead,' ' thickhead/ and othtr expressions of a like 

 meaning, it is evitlentlv the implied opiiuon of mankind, 

 that want of intellectual capaciu is p.oduccd bv a cause 

 similar to that of a substance in a state of condensation. 

 An exercise of the faculties has undoubtedly a tendency to 

 render the sentient substance more tenuous, and mon tilted 

 for thought and observation ; while illness, or any cause 

 which tends to derange the nerves and iluids, may be sup- 

 posed to condense it, and render it less sensible to the im- 

 pression of ideas. In sleep, the bodilv functions still con- 

 tinue; the nerves retain their irritability, the heart and ar- 

 teries continue their pulsation. It is probable that sleep is 

 produced more by a change in thj sentient substance than 

 in the body, though that change may be affected by phy- 

 sical causes of which we have no conception. II it will 

 not appear too extravagant a conjecture, I would suppose 

 that this insensibility to external objects is owing to the 

 action of matter on the soul, which it renders loo con- 

 densed to receive ideas: the sounder the sleep is, the more 

 perfect the condensation : when sleep is impertecf, memory 

 is at work, and presents to our minds a succession of 

 b'okcn and confused ideas, and these ideas will be clearer 

 as sleep is more imperfect, for then tl-c soul will be more 

 tenuous. 



When we speak f>f the Almighty as of a being purely 

 spiritual, we mean that he is perfect in his essence ; that is, 

 incapable of imperfection of any kind. Pure, when applied 

 to express an essence, means that such essence is perfect. 

 A pure sjiirit, therefore, means a perfect spirit; and what is 

 perfect must be incapable of imperfection : because, if any 

 essence contains within itself a capal)ilily of imperfection, 

 it is very clear ihat such es"?ence is not perfect. It is then 

 very evident that there can exist only one pure perfect 

 spirit, or one Being purely spiritual, wliieh is God ; and 

 thai such terms are applicable only to ilie Deity; for no 

 other being can be in his essence purely spiritual; for all 

 other beings are imperfect ; and an essence pnrelv spiritual 

 is necessarily perfect. Since, thereh)ie, the attributes of 

 mind cm in no other being belong to a substance purely 

 spiritual, it follows that our sentient p-rinciple ^for it is to 



earthly 



