Quintessence

quintessence \kwin-ˈte-sən(t)s\ noun: 1. the fifth and highest element in ancient and medieval philosophy that permeates all nature and is the substance composing the celestial bodies,
2. the essence of a thing in its purest and most concentrated form,
3. the most typical example or representative {the quintessence of calm}

Etymology: Middle English, from Middle French quinte essence, from Medieval Latin quinta essentia, literally, fifth essence

I can comprehend that a word denoting an element permeating everything can acquire the sense of “pure nature” or “representative example,” but viewed solely in relation to its literal etymology — “fifth essence” — it sounds funny. Wouldn’t you want your “first essence” to be your archetype?