That which is not, is not. "What-is-not" does not exist. Since anything that comes into being must arise out of what-is-not, objects, states of affairs and so on cannot come into being. Likewise, they cannot pass away, because in order to do so they would have to enter the realm of what-is-not. Since it does not exist, what-is-not cannot be the womb of generation, or the tomb of that which perishes. The no-longer and the not-yet are variants of what-is-not, and so the past and future do not exist either. Change, then, is impossible. Equally, multiplicity is unreal. The empty space necessary to separate one object from another would be another example of what-is-not. And since things cannot be anything to a greater or lesser degree—this would require what-is to be mixed with the diluting effect of what-is-not—the universe must be homogeneous.
Παρμενίδης ο Ἐλεάτης