Viviane,
I think I defined that more than a few times on this thread, but here is again: I take 'absent' in the simplest and most rational of its meanings: not present. It may include "exists, but not there", also "not paying attention/not caring", "existed in the past, now dead", or "non-existent". To say "absent" is to stop short of making any considerations about the existence of God, for the lack of evidence, while at the same time allowing for the possibility of any of them. If one day it would be possible to scan the entire universe in its entirety with all its dimensions and God could not be found, only then, beyond reasonable doubt, one could say "God/deities don't exist".
However, you have posed a question:
How do we know they are absent unless someone defines the specific properties of a deity so we know to look for it?
That's exactly the problem that absentheism attempts to address: Atheism assumes a certain kind of deity - invisible, all-powerful, all-knowing, omnipresent, entirely good and then debunks the notion that a deity like that may exist. But there are two problems with this, to wit:
- What about deities that are known to have existed and have been worshiped as such - Caesar Augustus, Aten, the Sun-Disc, or the emperor of Ethiopia Haile Selassie I (the Jah/Messiah of the Rastafarian movement)?
- What if a deity that exists leaves no physical footprint in the universe, doesn't communicate or interact directly with humans? What if said entity escapes any known definition that humans so far have come up with? How would we even collect evidence that it exists?
MASH
That axiom is also problematic for atheism, and is often used by theists.
Eden