Etymology

In classical times, with reference to meanings; later, to histories. Classical etymologists, Christian and pagan, based their explanations on allegory and guesswork, lacking historical records as well as the scientific method to analyze them, and the discipline fell into disrepute that lasted a millennium. Flaubert ["Dictionary of Received Ideas"] wrote that the general view was that etymology was "the easiest thing in the world with the help of Latin and a little ingenuity."

Latin etymologia, from Greek etymologia "analysis of a word to find its true origin," properly "study of the true sense (of a word)," 

The science goes way back. The Latins ere good at it, what else did the Latins have? Parchment. What is the most valuable book for a trader or governor? A foreign language text. Speaking Latin is like speaking from a robot created grammar machine, some set of rules constructed in debate in old Italy y a bunch of linguistic expert, a dictionary format. There was a huge payoff for getting this right, a multiplied by having the parchment monopoly for a start.