Full Idea
What each thing is when its coming to be has been complete, this we say is the nature of each - for example, of a human, or of a horse, or of a household.
Gist of Idea
The nature of each thing is its mature state
Source
Aristotle (Politics [c.332 BCE], 1252b32)
Book Reference
Aristotle: 'Politics', ed/tr. Reeve,C.D.C. [Hackett 2017], p.4
A Reaction
This works better for animate than for inanimate things. Aristotle is much clearer when we talk of the 'nature' of each thing, rather than its 'essence', because the latter has been blurred. I like 'essential nature'.