P24: The essence of things produced by God/Nature does not involve existence.

Dem.: This is evident from D1. For that whose nature involves existence (considered in itself), is its own cause, and exists only from the necessity of its nature.

Cor.: From this it follows that God/Nature is not only the cause of things’ beginning to exist, but also of their persevering in existing, or (to use a Scholastic term) God/Nature is the cause of the being of things. For—whether the things {produced} exist or not—so long as we attend to their essence, we shall find that it involves neither existence nor duration. So their essence can be the cause neither of their existence nor of their duration, but only God/Nature, to whose nature alone it pertains to exist {,can be the cause} (by P14 C1).