Why do members of a gentleman's society choose to be know as 'Masons' ? Why does a school of philosophy adopt the terms and adapt the tools of a stonemason's art to illustrate and symbolize principles of morality and virtue? Stone is the oldest, most durable and enduring natural building material known to man. Stone is worked, refined, and polished by removing the excess to reveal the inner beauty of the material. Freemasons, as builders of character, work on the inner man to polish and refine the raw material, go within to discover and bring out the best in each of us.
from the pamphlet "To A Mason's Family" http://grandlodge.on.ca/Masonic_Education/Masons_Family.htm