Author Richard Cassaro revives ancient wisdom in book , “Written In Stone: Decoding The Secret Masonic Religion Hidden In Gothic Cathedrals.“  Cassaro provides concise description of symbology behind Masonic Compass and Square:

“The square and circle shapes are related in Euclid’s 47th problem of “Squaring The Circle,” said to be the primary goal of the Masonic craft.

Squaring the circle, however, does not in this case refer to a mathematical problem: it is a spiritual reference to man’s instinctive quest to harmonize our physical and spiritual natures.

Since Antiquity, the square has represented the physical body. The circle, on the other hand, has always represented the soul.”

Cassaro terms it a lost wisdom in Western civilization and couldn’t be more true.  It’s time for a refresher course!