That all our distinct perceptions are distinct existences, and that the mind never perceives any real connexion among distinct existences.
Real things, in short, are distinct existences, and, as distinct, not necessarily or logically connected in thought.
A knowledge of being and existences (concrete, not abstract) and their mutual relations, is necessary as the beginning of philosophy.
Created beings were originally of three orders - the intelligent or angels; the non-intelligent natural existences; and man, who mediated between these two orders.
We learn from Plato (Parmenides, 127 D) that "the first hypothesis of the first argument" of Zeno's book above mentioned ran as follows: "If existences are many, they must be both like and unlike [unlike, inasmuch as they are not one and the same, and like, inasmuch as they agree in not being one and the same, Proclus, On the Parmenides, ii.