His most prominent thesis from this perspective was Flying saucers, the process of matter and energy, science, the revolutionary and working-class struggle and the socialist future of mankind (1968). Posadists believed that extra-terrestrials visiting earth in flying saucers must come from a socially and scientifically advanced civilisation to master inter-planetary travel and that the working-class should welcome the alien invaders as their liberators.
The author's most significant work, "Flying Saucers," explored the relationship between science, social revolution, and the future of mankind, particularly focusing on the potential for extraterrestrial visitors from advanced civilizations to liberate the working class.