Symbolism
Links
The Seven Liberal Arts
http://cosmopolis.com/villa/liberal-arts.html
Based on the types of studies that were pursued in the Classical world, the Seven Liberal Arts became codified in late antiquity by such writers as Varro and Martianus Capella.
The Symbolism of Freemasonry by Mackey, Albert Gallatin
http://moa.umdl.umich.edu/cgi/sgml/moa-idx?notisid=AHK6822
The complete text of a classic work on Masonic Symbolism. Presented as scanned images of individual pages through the "Making of America" archive.