Full Idea
The core of metaphysics is an account of the 'essence' or 'being' of things. ...And metaphysics needs system, to show how these primary truths reach out into all the other truths, to help us see that, and how, they are true.
Gist of Idea
Metaphysics aims at the essence of things, and a system to show how this explains other truths
Source
John Richardson (Nietzsche's System [2002], Intro)
Book Reference
Richardson,John: 'Nietzsche's System' [OUP 2002], p.3
A Reaction
I like the phrase 'the essential nature' of things, because it doesn't invoke rather dodgy entities called 'essences', but everyone understands the idea of focusing on what is essential, and on things having a distinct 'nature'.