WHY CALLED BY THE NAME OF CANON

The word Canon, from the Greek κανῶν, was used in a variety of senses by ancient authors. Originally it meant a rule or contrivance by which other things were kept straight; but in a secondary sense it was variously applied according to the nature of the case, always, however, preserving the idea inherent in its original meaning. In architecture it was the plumb-line or level; in weights and measures it was the tongue of the balance; in chronology it was the chief epoch or era; in music it was the monochord, or basis of all the intervals; and when applied in a literary sense it served to designate those writings which were to be distinguished from all others by the elegance and excellence of their diction. The Doruphoros of Polycletus was called by this name, and for this reason also the select extracts of many of the ancient Greek authors (Müller, Archäol. d. Kunst, § 120, 4; Ruhnken, Hist. Crit. Orat. Græc.; Quintilian, Inst. Rhet., 10). To this last acceptation of the word the Canon of the Mass has a thousand claims, for all admit that it is a work of rare worth—in fact, a model of perfection; for which reason, to pass over many others, it used to be formerly written in letters of gold (Marténe, De Antiquis Eccl. Rit., f. 34). Many writers, however, say that it is called the Canon because of its unchangeable nature; but to our mind this has never seemed a good reason, nor is it strictly true. The Canon does change on some occasions.