477 
this is a condition of onr being able to form a distinct concep- 
tion of it, we are compelled to postulate the existence of space 
beyond any conceivable definite limit we can assign to it. 
Still we have not reached a positive conception of infinite 
space. In attempting to frame such a conception, we must 
turn a negative one into a positive one. Negation as such 
cannot be conceived of as existing. What then has the mind 
really effected ? It has been compelled to introduce a concep- 
tion of finiteness into infinity itself, owing to that law of its 
constitution that finite thoughts and finite conceptions can only 
image the finite. If what we designate infinite space merely 
meant our finite conception pushed on in every direction 
without limits, Mr. Mill would unquestionably be right, that 
in adding infinity to finite space, we do not destroy our 
original conception of it. But in denying its finiteness, or in 
postulating its infinitude, have we not removed one of the 
factors in that conception ? These remarks seem to me to 
prove that after we have assumed the existence of the infinite, 
we have arrived at the region beyond which reason fails to 
supply us with certitude. 
There is a passage in Professor Kirk's paper which leads me 
to the same conclusion. “Can we not imagine," says he, 
“that beyond a certain range in the universe, there is nothing ? 
Can we not think this ? I insist that I can." My own ex- 
perience is, that although I can imagine this, yet, after having 
made many hard attempts, before and since I read his paper, I 
am unable to think it in any form which is not an airy and 
unsubstantial one, and I believe that the great majority of 
thinkers will find themselves in a similar position. “ I can 
think of a perfect vacuum," says he, “ and that is nothing. 
You may say that it is space ; but it is empty space, and that 
is nothing." I am unable to acquiesce in these assertions. 
Absolute non-existence is to me a thing which I am un- 
able to make the subject of thought. The only thing 
which I am able to make a definite subject of thought is ex- 
istence. A vacuum and empty space I can distinctly image to 
the mind. I can predicate of both of them that they exist. 
But I cannot predicate of nothing that it exists. The German 
transcendentalists have asserted the absolute existence of non- 
existence, and that it is the same thing as existence. This I 
am unable even to conceive. I only adduce this as helping to 
show that we have no rational powers which are capable of 
dealing with such subjects in our present state. They may be 
enlarged hereafter. 
We assume the possibility of the existence of infinity, and 
ascribe it to God. One portion of this conception is purely 
