Flar earth society is a psyop of the 1800s. Imo it's tight with the garbage theory of Darwin. Both are meant to mess with the correct cosmology and ultimately with the supersensible nature of humanity. Looking at how society has turned out, I'd say they were pretty successful. There are two types of useful idiots: the one who believe people come from monkeys and the ones who regard aliens as creators. 

 aren't those 2 groups  everyone or what is the 3rd way? 

 Divine spark in the beginning, although there's been alien fuckery later on imo.