"But Master," the young man protested while holding out two deformed stones, "these are merely rocks. How are these even relevant to our discussion?"
The old man shook his head and took the rocks. He opened the latch to the first of two small cylinders that stood quietly to one side of the long table on which was laid out an array of sparkling gems and rough cut stones.
"Child, do you not understand anything that I have taught you?"
His apprentice bristled at the rebuke but said nothing.
"Watch, child."
The Master placed both rocks into the cylinder.
"Do you know why we put sand into the tumbler?"
A long sigh escaped the lips of the other as he began to speak in a rote tone. "Because it provides the friction necessary to polish the stones and provide a simulation to the natural forces that usually affect the stones."
"No," came the response. "We use sand because it is earth working on earth, stone working on stone. It is the sum of the rock shaping the rock itself."
He stopped and looked over his glasses at the young man who was obviously hurt over the admonishment of his Master and not grasping the concepts he was being shown. The old man then took several handfuls of sand and placed them in the tumbler.
"Come. Turn the wheel and let me show you again what happens when we place two objects together, united by the sand and the ever-turning motion of their circumstance."
The apprentice began to turn the handle on the cylinder as the Master opened up the second tumbler and reached inside. He pulled out two brilliantly polished stones that sparkled in the lamplight.
"Beautiful, indeed. How much more akin to two human hearts could they be …"