When we use the word quintessential today, we use it to mean “something is typical or representative of a particular kind.” So to an American, apple pie is the quintessential pie, perhaps. (Let’s not start a heated debate here, now, you cherry lovers! It’s just an example, LOL.)
But let’s look at the word, going back to the root word, quintessence, for a minute. Quint, we know, is Latin for “five.” And essence is, well, essence. 😉 Something’s very being. So when we put that together we get “fifth essence.” Which, hmm. What does that mean?
It starts clicking into place when you replace essence with a synonym in meaning here, element. The ancient world understood all matter as being composed of four main elements in various combinations: fire, water, earth, and air. The fifth element or essence, then, was thought to be something heavenly, something pure that imbued all things. The pure being that is in all of us and everything around us.
This fifth essence was thought to be incorruptible, pure, bright. It was of course nullified in most things by the other elements, but if you get at it…if you could get to the heart of a thing, to its being, to that purest of essence…well, that was the quintessence, or the quintessential part.
The word itself has been around since the Middle Ages, entering English in the early 1400s. In Medieval alchemy, in fact, the attempts to do things like turn lead into gold was all about finding the quintessence and bringing it out. And so too today, in our metaphorical meaning, something that typifies a kind will represent it purely.