I learned three things in Zurich during the war. I wrote them down. Firstly, you’re either a revolutionary or you’re not, and if you’re not you might as well be an artist as anything else. Secondly, if you can’t be an artist, you might as well be a revolutionary… I forget the third thing.

The speaker’s mock-aphoristic “three things” collapses into a comic binary: revolutionary versus artist. The joke is that the categories are treated as mutually substitutable life-roles—if you lack the temperament for one, you may as well adopt the other—suggesting that both are, in different ways, performances of conviction. The forgotten “third thing” undercuts the pose of hard-won wartime wisdom, hinting at the fragility of ideological certainties and the ease with which grand principles become rhetoric. In Stoppard’s typical mode, wit becomes a tool for examining political seriousness: the line satirizes the urge to systematize experience while still acknowledging the pressure, in crisis, to choose a stance.