16 



that we are no longer conscious of its existence ; this is also ex- 

 perience. Our terms of knowledge express very little more than 

 the consciousness which the mind has of its own state: thus it is 

 conscious of being under some sensible impression ; the cause of 

 this impression being removed, it is conscious that it is not under 

 the past, but some present, some other impression. 



5. The belief of the absence of existence is founded upon 

 a presumption with which the mind is possessed, of the ability of 

 the senses to perceive whatever external objects do exist. If the 

 senses perceive nothing in any place or direction, it is concluded 

 that there is nothing in such place or direction. If the proof of the 

 truth of this conclusion should be inquired for, I reply that such 

 is the conviction which the mind has, and which is synonymous 

 with truth, and is as much as can be offered for the truth of a 

 real presence, or for the existence of positive properties. 



6. There are exceptions to this intuitive assurance which the 

 mind feels of the ability of the senses to discover whatever is 

 within the sphere of their relation. When we regard what might 

 be called an unoccupied atmosphere, those who know any thing 

 of chymistry would be convinced that they did not regard mere 

 vacuity, that the field of their vision was in fact occupied by 

 oxygen and azote, real existences. This belief is acquired in the 

 way before mentioned, viz. by inference: but when an inference 

 does not help us to the conviction of some real presence, and our 

 senses also fail to discover such real presence, then we trust to 

 the presumed sufficiency of the senses, and believe that there is no 

 real presence: and we act upon this belief: and we seldom err in 

 consequence of this reliance, because our sensible relations are in 

 general uniform and consistent. 



7. An ignorant man need not go far for his example, if I may 

 so say, of nothingness: not knowing the nature, properties, laws, 

 &c. of the atmosphere in which he lived, he would be ready to 

 affirm that there was nothing in a bell glass, because it contained 

 nothing cognizable to the senses. Antecedent to that knowledge 

 which constitutes the base of our inference, about the constitu- 

 tion of air, the presence of properties, &c. we also should attain 

 the same conviction of nihility in the same example. But as the 

 case stands, if we remove the air from the bell glass, we then have 

 a specimen of the entire absence of any thing existent, there being 

 no substance contained in it, according either to the testimony of the 

 senses or of the understanding. It is an ancient, and, as it ap- 

 pears, an indisputable truism, that no real existence can arise in 

 this vacuum unless it should be admitted, or unless something, as 

 its elements, should be admitted from without: it is hence 

 concluded, 



8. That as nothing (or the vacuum) must for ever remain 

 nothing, so this state of nihility can be changed or interrupted 

 only by some positive cause. Thus far the matter is very clear. 

 But the inference proceeds to affirm, that as a real existence 



