Authors:

Dad was a philosopher and had what he called his Theory of Purpose, which held that everything in life had a purpose, and unless it achieved that purpose, it was just taking up space on the planet and wasting everybody's time.

Jeannette Walls (2009). “Half Broke Horses: A True-Life Novel”, p.24, Simon and Schuster
Dad was a philosopher and had what he called his Theory of Purpose, which held that everything in life had a purpose, and unless it achieved that purpose, it was just taking up space on the planet and wasting