PART IV: In the 1800s, the idea of a Plurality of Worlds was challenged by the fact that, just as stars are not all other suns, planets are not all other earths — and that even on those planets that might be other earths, inhabitants might not naturally spring out of the ground.
PART II: When thinkers like Fontenelle popularized the idea of a Plurality of Worlds in the 17th century, it grew to be widely supported by astronomers — but science offered nothing to support it, and offered easily reproducible results to question it.
Galileo did not prove that the Earth moves. He did not invent the telescope. He was not excommunicated, tortured or burned. So where do these ideas originate?