Also as a side note: I think this is so important that we will eventually want to add another bullet point to the opening list of key takeaways for new readers (the top of the front page).
So it would be good to look for pithy passages from the ancient Epicureans that summarize the point, which is something like:
Reasoning about the nature of the imperceptible must be based on and consistent with the nature of the perceptible.
What we're getting at here is probably the most basic Canonical assertion of Epicurean philosophy.
It is the method for deriving, and being confident of, both the affirmative existence of atoms and void as well as the non-existence of supernatural gods and consciousness after death (immortal souls).
But it must be stated in a way that makes clear why, at the same time, BOTH (1) people who have lived all their lives inland would not declare oceans to be impossible, and also (2) people need not live forever or travel the entire universe before they can affirm that supernatural gods are impossible.
So suggestions for text references which say something like the italicized section above will be appreciated. I expect we have this in Herodotus and Lucretius and probably other places as well.
For example from Herodotus:
QuoteAnd besides we must keep all our investigations in accord with our sensations, and in particular with the immediate apprehensions whether of the mind or of any one of the instruments of judgment, and likewise in accord with the feelings existing in us, in order that we may have indications whereby we may judge both the problem of sense perception and the unseen.
I can't confirm the Greek, but, for example, it seems important in this passage that the phrasing would be "perceptIBLE" (able to be perceived) rather than "that which has already been perceived."