J9B, let's run with your analogy:
Is there a difference between saying, (1) "there are aliens of a particular kind out there. They have X characteristics, and do Y sorts of things," and (2) "there are aliens out there, but I'm not really sure what they are like"?
(I can think we can agree that there is a difference).
Most religions (theistic) seem to go with the (1) approach. Pantheists or "there's some higher power thingabob out there" go with the (2) approach.
Now, do atheists reject both (1) and (2)?
And, if probability is deemed good enough for determining truth, then is (1) more probable to be true, or is (2) more probable?*
*
It seems that most atheists are definitely atheist regarding claims similar to (1) and (2), but some atheists (perhaps, "agnostic atheists") reject (1) but not quite (2).