"This is the true joy in life, the being used for a purpose recognized by yourself as a mighty one; the being thoroughly worn out before you are thrown on the scrap heap; the being a force of Nature instead of a feverish selfish little clod of ailments and grievances complaining that the world will not devote itself to making you happy." (George Bernard Shaw)
These lines are from the "Epistle Dedicatory" Shaw included with his script for Man and Superman. He is writing to Arthur Bingham Walkley, the English theatre critic who gave him the idea to write a Don Juan play, and Shaw's wide-ranging discussion eventually lands on this statement of artistic values, which he ascribes to the artist-philosopher. Turns out that Shaw's actually taking a stab at Shakespeare here, whom he calls a "fashionable author who could see nothing in the world but personal aims and the tragedy of their disappointment or the comedy of their incongruity" rather than the "constructive ideas" he wants artists to espouse.