A zen adept walks into the bar. He sits down, and the bartender pours him half a glass of water.

"Now tell me," the bartender/master asks the young adept, "Is the glass half empty or half full?"

The adept picks up the glass, holds it up to light, sloshes it slghtly as if pondering the liquidity, the watery-ness of the water in the glass, the interplay of liquid and air, the yin and yang of 'filled' and 'space'.

He throws the water into the bartender's face. "I ordered a Beer, dammit."