The Position and Possibilities of the Masonic Order from The Meaning of Masonry by Walter Leslie Wilmshurst.

“An elementary and formal secrecy is requisite as a practical precaution against the intrusion of improper persons and for preventing profanation. In other respects the vital secrets of life, and of any system expounding life, protect themselves even though shouted from the housetops, because they mean nothing to those as yet unqualified for the knowledge and unready to identify themselves with it by incorporating it into their habitual thought and conduct.” [via]