I guess art falls into the necessary-but-not-sufficient category in human existence. We *need* art, but art alone isn't going to do it for us--and you can replace "it" with "sustaining life" or "achieving freedom" or probably bunches of other things.

Revolutions are always going to require hard, awful work--a daunting reality that gets less daunting the more hard and awful the circumstance necessitating the revolution is.