Full Idea
If the thing has being, it has it in a certain way and, if it does not have being in a certain way, it does not have being at all.
Gist of Idea
There is only being in a certain way, and without that way there is no being
Source
Aristotle (Metaphysics [c.324 BCE], 1051b34)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.282
A Reaction
I take this to be a key remark in ontology, and one that may not have been sufficiently heeded by Hegel and Heidegger. The only way to investigate being qua being is to investigate ways of being, which involves identity, categories etc.