Natura naturans is a Latin term coined during the Middle Ages, meaning "Nature naturing", or more loosely, "nature doing what nature does". The Latin, naturans, is the present participle of natura, indicated by the suffix "-ans" which is akin to the English suffix "-ing." naturata, is the past participle. These terms are most commonly associated with the philosophy of Baruch Spinoza

Baruch Spinoza

Baruch de Spinoza and later Benedict de Spinoza was a Dutch Jewish philosopher. Revealing considerable scientific aptitude, the breadth and importance of Spinoza's work was not fully realized until years after his death...

. For Spinoza, natura naturans refers to the self-causing activity of nature, while natura naturata refers to nature considered as a passive product of an infinite causal chain. Samuel Taylor Coleridge

Samuel Taylor Coleridge

Samuel Taylor Coleridge was an English poet, Romantic, literary critic and philosopher who, with his friend William Wordsworth, was a founder of the Romantic Movement in England and a member of the Lake Poets. He is probably best known for his poems The Rime of the Ancient Mariner and Kubla...

 defined it as "Nature in the active sense" as opposed to natura naturata

Natura naturata

Natura naturata is a Latin term coined in the Middle Ages, mainly used by Baruch Spinoza meaning "Nature natured", or "Nature already created". The term adds the suffix for the Latin past participle to create "natured"...

.
The distinction is expressed in Spinoza's Ethics

Ethics

Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...

as follows:

[B]y Natura naturans we must understand what is in itself and is conceived through itself, or such attributes of substance as express an eternal and infinite essence, that is … God, insofar as he is considered as a free cause.
But by Natura naturata I understand whatever follows from the necessity of God's nature, or from God's attributes, that is, all the modes of God's attributes insofar as they are considered as things which are in God, and can neither be nor be conceived without God.