A senior monk had applied for admittance into the temple. The Abbess Jinyu was called in to investigate the man.

“I will dictate a domain,” she said, gesturing at the whiteboard with her cane. “You will model an implementation in Java.”

The monk bowed and uncapped a green marker.

“All soldiers of the Imperial Army must know their rank,” began the abbess. “The Emperor may order a soldier to fight to the death, and no one but a soldier can be told to do this...”

The monk bowed and drew a rectangle, inscribed with instance variables and methods as was his custom.

“Some soldiers are archers,” continued the abbess, “each of whom must know the number of arrows in their possession. The Emperor may order an archer to shoot a distant foe, and no one but an archer can be told to do this...”

The monk bowed and drew a second rectangle, joined to the first.

“Some soldiers are horsemen,” continued the abbess, “each of whom must know the horse they have been assigned. The Emperor may order a horseman to trample the enemies in his path, and no one but a horseman can be told to do this...

The monk bowed and drew a third rectangle, similar to the second.

“Finally,” concluded the abbess, “Some soldiers belong to the Flying Rain of Fire, a cadre whose members are both archers and horsemen in every respect. The Emperor may order his Flying Rain to lead the charge, and no one but the Flying Rain has this privilege.”

The monk hesitated. For a full minute he did nothing but frown at the whiteboard; all present could sense the fierce calculations taking place behind the monk’s calm visage.

A nun of the temple whispered to Jinyu: “This problem has several solutions, but I dislike all of them.”

“Therein lies its value,” whispered the abbess in reply. “For we are all of us doomed in this profession: our designs may aspire to celestial purity, yet all requirements are born in the muck of a pig-sty. I trust that this monk can succeed when the stars align in his favor, but when they do not, how will he choose to fail? By cowardly surrender? By costly victory? By erroneous compromise? For it is not he alone but the temple that must bear the consequences.”