When the tour was over, we were released on our own recognizance to explore the galleries and gift shop on the basement level. There, we found a small room tucked into the corner with an exhibit called The Form and Function of American Freemasonry.
The information included there was a little more concrete and focused on four American leaders who were also Freemasons: George Washington, Ben Franklin, Andrew Jackson, and Harry Truman. Even so, the content was still rather opaque, and we understood that we really weren't supposed to understand what the heck was going on, at least not in any specific way.
One display did draw both our attention, though. In the center of the room was a glass case with two cube-shaped stones, one very rough and the other polished and smooth. They were ashlars, the term for stones cut to be laid in courses. The ashlar is the central allegory of Freemasonry: the rough stone represents an individual before entering the brotherhood.
Once a man is accepted, the masons work to refine and polish him so he may take his place in the living wall of brotherhood. The highest-ranking member of each lodge is the Worshipful Master, and he is charged with supervising the Craft using the tools of the trade: the gavel, chisel, square, and compass.
Now that metaphor was something a couple of retired English teachers could wrap their brains around.