Full Idea
In 'Categories' Aristotle argues the primary being (proté ousia) is the ultimate subject of predication (to hupokeimenon, meaning 'that which lies under'), nowadays referred to as the 'particular substance' view.
Gist of Idea
Primary being is 'that which lies under', or 'particular substance'
Source
report of Aristotle (Categories [c.331 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 4.4
Book Reference
Politis,Vasilis: 'Aristotle and the Metaphysics' [Routledge 2004], p.110
A Reaction
Politis says that Aristotle shifts to the quite different view in 'Metaphysics', that primary being is essence, rather than mere subject of predication.