Full Idea
The simple's whatness is its very self.
Gist of Idea
The simple's whatness is its very self
Source
Avicenna (Abu Ibn Sina) (Commentary on the Metaphysics [1022], 5.5), quoted by Thomas Aquinas - De Ente et Essentia (Being and Essence) p.103
Book Reference
Aquinas,Thomas: 'Selected Philosophical Writings', ed/tr. McDermott,Timothy [OUP 1993], p.103
A Reaction
Aquinas endorses this Aristotelian view in Idea 11208.
Related Idea
Idea 11208 A simple substance is its own essence [Aquinas]