Aristotle added a fifth element, aether, as the quintessence, reasoning that whereas fire, earth, air, and water were earthly and corruptible, since no changes had been perceived in the heavenly regions, the stars cannot be made out of any of the four elements but must be made of a different, unchangeable, heavenly substance.
Aristotel je kao kvintesenciju dodao etar, smatrajući da su vatra, zemlja, vazduh i voda zemaljski i stoga kvarljivi elementi, a da pošto se nikakve promene nisu opazile u nebeskoj sferi, zvezde se ne mogu sastojati od bilo kojeg od ova četiri elementa, nego moraju biti napravljene od neke drugačije i nepromenljive materije.