Three. One to hold the light bulb do and two to spin the chair
Two, one to change the light-bulb, and one to observe how it symbolizes an incandescent beacon of subjectivity in a netherworld of cosmic nothingness. This is courtesy of Spencer Reid.(CM)
Why are you asking me that question Can't you see I'm busy!
A Chair-ity!
Because they don't have any chairs. Source: my five-year-old.