The man nods slowly and then begins to speak...
Yes, motion and change seem to be popular topics around here. Our friend Diodorus correctly noted that any such discussion involves a model that we have reached by reason. We may perceive a thing over here, then perceive it over there, but how we describe and relate those moments and their content is more complicated. Even that overview hides complexity! For example, at the later perceptive moment we are relying on our memory of the earlier moments. Although, perhaps I am misleading you there, for it is also wrong to speak of the later moment as though we formulate the model while in it, as a sort of uniquely privileged point. At any rate, it's not that I deny there's something to be discussed, so much as I want to warn outsiders of their careless assumptions.
As an aside, Diodorus put forward an alternative to the typical ways we define a term. Philosophers have argued about whether a term has an inherent meaning, or whether a term is defined by common agreement. Diodorus inserted a third challenger - the term is defined by the intent of the speaker. There is so much to say about this great soul, yet we have little to remember him by beyond testimonia from later authors. It is said, "With this character's death, the thread of prophecy is severed." Given the apparent loss of his works, it sometimes feels like we are in a benighted era.
Anyway, don't let me get distracted; we were discussing his views on motion. If we go over the source material, you'll see that he was a very Zeno-like figure. He came up with many tricky scenarios, thereby revealing that his opponents' models of change were incoherent. If we follow his reasoning, we'll discover that there is motion but that things are not moving. If you have spoken to others in this temple, perhaps you already see the truth of this. Recall Zeno's arrow: at which point is it "in motion"? Motion exists, but it consists of a relationship between points; it is diffuse. The term "in motion" only makes sense when the chronology is taken as a whole, for at any given moment a thing is only in its place.
Let me use another example: take a ball and throw it on a roof. When does the process of "touching" occur between the ball and the roof? If the ball is in the air, they are separate. If the ball is on the roof, they are in contact. There is no particular moment that exhibits a third relationship, one distinct from contact or separation. Similarly, there is no point where a wall collapses - it is either standing or rubble. I sense your soul rebels, but tread carefully. In examining motion you will find that all is unmoved. Motion is diffuse, which in turn necessitates a chronology that is complete.
Let me try another approach. You will die, yes? But if so, you will die either when you are living or when you are dead. Surely it doesn't happen when you are alive, for then you are alive and not dead! Yet, surely it does not happen when you are dead, for at that point to die would bring about a second death. Each particular moment you would identify fails to capture the change you are seeking. Therefore, we must broaden our scope, whereupon we realise motion is diffuse. It can only be appreciated by those who appreciate the Whole.
There is so much left unsaid here; I have high hopes for this exhibit. Consider that Helen has three husbands. Ask when a wall is falling. Tell me how a thing can come to be and then perish. On this last point, it cannot come to be, for at the point prior to its existence it is not and therefore is not coming from there. And should you have it perish, yet it remains in that moment where we originally found it. It will not even budge an inch! It is ridiculous to say a thing is where it is not, and is not where it is.
The man scoffs and sighs to himself, then smiles at you.
Sorry, now I am being belligerent. At any rate, Zeno took a particular approach and Diodorus expands his repertoire in significant ways. I have only scratched the surface with what I have said today. All would do well to further explore the issues raised by Zeno and Diodorus. They are eristics, striking down those who rebel against the sages, Parmenides and Melissus. By their grace we do not succumb to incoherence and we need not fear those who would obstruct our path to the truth.
With that, the man appears lost in thought. Eventually he perks up and suggests that you either head to the general exhibit on change, or retire to the guesthouse. You decide to...