Selection from – Ethics – Part I. Of Deus sive Natura (Page 6)
Spinoza's Words: (all things operate as they should- natura naturans and natura naturata)
Proposition. XXIX. Nothing in the universe is contingent, but all things are conditioned to exist and operate in a particular manner by the necessity of the divine nature.
Whatsoever is, is in (Deus sive Natura). But (Deus sive Natura) cannot be called a thing contingent. For he exists necessarily, and not contingently...
Note.—Before going any further, I wish here to explain, what we should understand by nature viewed as active (natura naturans), and nature viewed as passive (natura naturata). I say to explain, or rather call attention to it, for I think that, from what has been said, it is sufficiently clear, that by nature viewed as active we should understand that which is in itself, and is conceived through itself, or those attributes of substance, which express eternal and infinite essence, in other words (Deus sive Natura) , in so far as he is considered as a free cause.
By nature viewed as passive I understand all that which follows from the necessity of the nature of (Deus sive Natura), in so far as they are considered as things which are in (Deus sive Natura) , and which without (Deus sive Natura) cannot exist or be conceived.
Comment:
Because the Laws of Nature (part of the essence of (Deus sive Natura)) are unchanging all things in nature behave the way they do. Things, therefore, could not be different than they are.
Spinoza distinguishes two aspects of Nature with the phrases natura naturans and natura naturata. By the former he means nature begetting, an active process, think of evolution. By natura naturata he means nature begotten, passive, the products of the process; trees, streams, mountains, animals, plants, stars, planets, et al.
It is with natura naturans that Spinoza identifies (Deus sive Natura) (God or Nature). He denies that (Deus sive Natura) is in natura naturata (the physical universe of things). That separates him from the pantheists. A charge that some writers have accused him of.