Originally Posted by AWPrime
These correspond pretty nearly to my numbered points that rebut the argument based on Fermi's Paradox as well.
I would point out that "too far" could be in space and time
. We don't know that civilizations can last longer than our own. If they're relatively short-lived, like most of the other species that have existed on our own planet, then the argument that they must have filled up the galaxy with evidence of their presence long before now doesn't hold up.