Q: How many Zen masters does it take to screw in a lightbulb?
A: <smash the lightbulb>
OK, try again.
Q: How many Zen masters does it take to screw in a lightbulb?
A: Five. Two to argue over whether the buddha nature already resides in the empty socket, one to light a candle instead, and two to shovel out the outhouses.
On a related topic:
Q: How many psychoanalysts does it take to screw in a lightbulb?
A: How many do you think it takes?