to be susceptible. The essence is itself susceptible to the attribute inhering in it; its susceptibility to that susceptibility would therefore be additional to it, entailing an infinite regress.

We maintain that, since susceptibility as such is a negative determination, susceptibility to division must likewise be so, because susceptibility to division is a particular kind of susceptibility. If this particularity were an existent attribute, existence would have to inhere in nonexistence, which is impossible. If it were a negative determination, we would have to conclude that susceptibility to division is a negative determination. Once this is established, it cannot admit of causal explanation, for nonexistence is sheer negation, and no causal influence upon it is possible. Thus, susceptibility to division cannot admit of causal explanation.

The third objection: Grant that it is a positive determination. Why could it not be causally explained specifically by being a substance or specifically by being an accident?

You say: “Because being a substance precludes spatial coincidence, while being an accident precludes spatial separation; and whatever causes susceptibility to division into two alternatives cannot preclude either alternative.”

We reply: What do you mean when you say, “What exists in the observable world is divided into what is spatially coincident and what is spatially separate”? If you mean that what exists in the observable world falls into two classes: