Anaxagoras was a philosopher who could not agree that one particular basic substance- water for instance- might be transformed in blood and bone. Anaxagoras believed that nature was built up of an infinite number of minute particles, invisible to the eye. More than that, he also believed that everything can be divided up into smaller parts, and even in the most minute parts there are still fragments of yet smaller particles.
Anaxagoras moved to Athens from Asia Minor, at the age of fourty. He was the first known philosopher from Athens. After Anaxagoras moved to Athens, he began to gather followers. Eventually his beliefs became so fanatical, as others saw it, that he and his followers were exiled from Athens. Among other "strange" and "alien" beliefs, Anaxagoras believed that the Sun was not a god but a red-hot stone, bigger than the entire Peloponnesian peninsula.
Anaxagoras was also very fascinated and interested by astronomy. Anaxagoras held that the "celestial bodies" were made up of the same substance as Earth. This gave him the idea that there could be human life on other planets. He also showed that the Moon has no light of it's own- it's illumination came from Earth. Anaxagoras also thought up an explination for solar eclipses.
Another interesting fact: Much like Empedocles, Anaxagoras thought that the bond which joined all things together, was "order" and not "love" as Empedocles had said. He also devised many of the popular theorums that are used in modern science.