The term esoteric has a fascinating history. It was first used in a 1660 history of philosophy, spelled as esoterick, and derived from the Ancient Greek word esoterikos, meaning “belonging to an inner circle”. This concept was initially associated with the teachings of Pythagoras, which were only meant for his select followers. The term itself comes from the comparative adverb esotero, derived from eso meaning “within”, and ultimately traces back to Proto-Indo-European ens, meaning “in”. On the other hand, the opposite of esoteric is exoteric, which means “understood by the general public”. This term comes from Ancient Greek exoterikos, meaning “belonging to an outer circle”, and can be traced back to PIE ex-, meaning “out of”. While both words have seen an increase in usage recently, esoteric is used significantly more frequently than exoteric, making exoteric the more obscure term.
