John Stuart Mill,
Principles of Political Economy
“ By Unproductive Labor, on the contrary, will be understood labor which does not terminate in the creation of material wealth. And all labor, according to our present definition, must be classed as unproductive, which terminates in a permanent benefit, however important, provided that an increase of material products forms no part of that benefit. The labor of saving a friend's life is not productive, unless the friend is a productive laborer, and produces more than he consumes. ”
