From the Latin ordinal number quīntus, meaning "fifth," and noun essentia, meaning "essence or being," the adjective quintessential means something that is commonly accepted as a "perfectly typical or representative of a particular kind of person or thing." The reason why the Latin words "fifth essence" came to mean a "perfect representation," however, requires a little history of ancient philosophy and science. In antiquity (and the Middle Ages for that matter), philosophers believed there were four essential elements: earth, air, fire, and water. Aristotle believed there was a fifth element—the aether or ether—which he understood to be the "stuff" that made up everything else. In the Middle Ages, this "fifth element" came to be called the quinta essentia, and represented the perfect, or quintessential representation of anything on earth or under heaven.