Seeking Atlantis: A lesson in Ampliation

Noneism holds that we can interact (that is, have a form of relationship with) non-existent objects. Priest gives us our first in-depth look into this noneism in chapter 3.2. I will clarify his use of Buridan’s sophism using insights from the appendix (3.7.1).
Buridan’s sophism reads “A non-being is understood” (57). Some may find it interesting that Buridan denies this sophism, though Priest cites him as a noneist. How could Buridan deny this sophism while claiming “the Antichrist is understood” is true? Surely we know that there was no Antichrist (literally speaking) in Buridan’s day, so to Buridan the Antichrist would appear to be a non-being. This would lead to a contradiction (the non-being is not understood & the non-being is understood).
Buridan’s way out of the contradiction was to deny that the Antichrist was a non-being, though he did not exist at the time. A non-being, Buridan held, is only that which is impossible (71). For example, the chimera that is concomitantly composed of the essences of lion, goat and serpent is a non-being. In contrast, non-existent beings (note the subtle difference in expression), like the Antichrist, could be the predicates of meaningful sentences. How? With the accompaniment of verbs that ampliate.
Priest says, “The standard classes of object to which ampliation allowed access were the past, the future, and the possible” (70). Ampliation is done by changing the tense of the verb, or designating possibility with a word like “can”. These ampliating verbs are the key to allow us to talk about non-existent beings. For example, the truth value of the sentence “Plato is walking” is false, because it looks to find the actual man designated by the proper name “Plato”, who obviously does not still exist. But when we change the verb to its past participle, the sentence “Plato walked” becomes true. Because the tense associates the subject to the realm of past events and objects, it is said to ampliate.