ancient philosophy, related to the possibility of extraterrestrial life

The idea that there might be other inhabited worlds dates back thousands of years and has roots in both Eastern and Western thought. Doubtless it first took the form of beliefs in gods, goddesses, and other spiritual beings which inhabited realms beyond the Earth. On a more intellectual level, Buddhism taught pluralism, as did some of the schools of Greek philosophy. Of the latter, atomism, as developed and propagated notably by Leucippus, Democritus, Epicurus, and Lucretius, is the most significant because the concept of multiple worlds and life is implicit in its cosmological scenario. Prominent among other ancient philosophers who speculated about the possibility (or impossibility) of other worlds and life, or who made discoveries relevant to these subjects, were


   Thales of Miletus
   Anaximander of Miletus
   Anaximenes of Lampsacus
   Anaxagoras of Clazomenae
   Aristarchus of Samos
   Eratosthenes of Cyrene
   Hipparchus of Nicea
   Lucian of Samosata