This word is used in Masonry in two senses entirely different; indeed, though spelled and pronounced the same, they are really two words. “Mystery” in the sense of strange, unknown, weird, secret, hails from the Greek, .in which muein meant to close the eyes, lips and ears; from this came musterion, a secret ceremony or doctrine, appearing in Latin as mysterium. The word mystery, thus derived, means secrecy, hiddenness, and is properly used of the esoteric elements in Masonry. But in the phrase “arts, parts and mysteries” the word is from the Latin ministerium, having the meaning of trade, art, craft, occupation, etc., preserved in the familiar metier from the French, often used as an English word, and the much more familiar “minister,” “ministry,” etc.; in this sense -- the sense most often used in our Craft the “mysteries of Masonry” are its workings, just as the mysteries of Operative Masonry were its trade secrets known only to those trained and skilled in the building arts. In the latter of the two senses “mystery” and “master” (see above) are closely affiliated in origin, a master being one who has become completely skilled in mysteries.