William DeWitt Hyde - Unsatisfied desire is the characteristic feature of human life. That is the

Unsatisfied desire is the characteristic feature of human life. That is the common fact out of which both pessimism and optimism are constructed. Dwell on the impossibility of ever getting a state of complete and permanent satisfaction with what you have, and you become a pessimist. Dwell on the opportunity for endless growth and conquest which this same fact makes possible, and you become an optimist.

- William DeWitt Hyde

topic: Opportunity, Optimism, Growth, Optimism In Life, Optimists And Pessimists, Unsatisfied