CHAPTER IV.
The difference between the possibility of conceiving of nonexistence, and understanding nonexistence.
YOU say, moreover, that whereas I assert that this supreme being cannot be conceived not to exist, it might better be said that its nonexistence, or even the possibility of its nonexistence, cannot be understood.
But it was more proper to say, it cannot be conceived. For if I had said that the object itself cannot be understood not to exist, possibly you yourself, who say that in accordance with the true meaning of the term what is unreal cannot be understood, would offer the objection that nothing which is can be understood not to be, for the nonexistence of what exists is unreal: hence God would not be the only being of which it could be said, it is impossible to understand its nonexistence. For thus one of those beings which most certainly exist can be understood not to exist in the same way in which certain other real objects can be understood not to exist.
But this objection, assuredly, cannot be urged against the term conception, if one considers the matter well. For although no objects which exist can be understood not to exist, yet all objects, except that which exists in the highest degree, can be conceived not to exist. For all those objects, and those alone, can be conceived not to exist, which have a beginning or end or composition of parts: also, as I have already said, whatever at any place or at any time does not exist as a whole.
That being alone, on the other hand, cannot be conceived not to exist, in which any conception discovers neither beginning nor end nor composition of parts, and which any conception finds always and everywhere as a whole.
Be assured, then, that you can conceive of your own nonexistence, although you are most certain that you exist. I am surprised that you should have admitted that you are ignorant of this. For we conceive of the nonexistence of many objects which we know to exist, and of the existence of many which we know not to exist; not by forming the opinion that they so exist, but by imagining that they exist as we conceive of them.
And indeed, we can conceive of the nonexistence of an object, although we know it to exist, because at the same time we can conceive of the former and know the latter. And we cannot conceive of the nonexistence of an object, so long as we know it to exist, because we cannot conceive at the same time of existence and nonexistence.
If, then, one will thus distinguish these two senses of this statement, he will understand that nothing, so long as it is known to exist, can be conceived not to exist; and that whatever exists, except that being than which a greater cannot be conceived, can be conceived not to exist, even when it is known to exist.
So, then, of God alone it can be said that it is impossible to conceive of his nonexistence; and yet many objects, so long as they exist, in one sense cannot be conceived not to exist. But in what sense God is to be conceived not to exist, I think has been shown clearly enough in my book.
