Esoteric (a.) - You wouldn't even begin to understand
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History & Etymology
The word esoteric was originally attributed to Aristotle as a classification of his written material. Exoteric referred to materials meant for consumption by the general public, and esoteric on the other hand referred to materials more appropriate or meant for the students within his school, the Lyceum.
The Oxford English Dictionary notes in their etymology of the word esoteric that Aristotle never used used the words esoteric in this way. He’s only recorded as use the word exoteric and then he only meant it in the sense of popular or nontechnical.
The word esoteric was first used in writing in the works of Lucian a satirist and rhetorician who lived around the mid 100s AD. He was the first to ascribe this classification system to Aristotle.
Esoteric was then borrowed into the English language and was used in writing for the first time in the 1600s in Thomas Stanley’s 4 volume book entitled History Of Philosophy. Thomas uses the word esoteric to refer to secret doctrines that Pythagoras, yes the triangles guy. Pythagoras would share these esoteric doctrines only among a select few of his disciples who had mastered his material.
Now we can trace the origin of greek root eso- in esoteric comes from the Proto-Indo-European word ens- or enso- which is the extended form of the root Proto-Indo-European root en- which mean “in” and is the origin of the English word in.