Are the Rare Earthers Optimists?
Given what we know now after 50 years of space exploration, it is still entirely possible that the assembly of the 1st living organism on Earth was a once in a universe event. Sure, we know thet there's plenty of 'organic' C-N-O-H etc. material around the galaxy, but we still do not have any scientificly falsifyable theories of how life 1st started. Folks programmed on Saganism automatically spout on about 'billions and billions' of planets and years, but if the probability of life 1st starting is say an exponent 10 -66 probability event (a number NOBODY has the faintest clue about), then we're it. It's just that the possiblility of life here being unique is not a popular idea in today's culture.