Full Idea
To be an object is to be a predication subject, and to be this as opposed to that particular object, whether existent or not, is to have a distinctive combination of properties.
Gist of Idea
An object is a predication subject, distinguished by a distinctive combination of properties
Source
Dale Jacquette (Ontology [2002], Ch. 2)
Book Reference
Jacquette,Dale: 'Ontology' [Acumen 2002], p.59
A Reaction
The last part depends on Leibniz's Law. The difficulty is that two objects may only be distinguishable by being in different places, and location doesn't look like a property. Cf. Idea 5055.
Related Idea
Idea 5055 No two things are totally identical [Leibniz]