You don't. You try the key on the lock, and if it doesn't work you keep looking for another key. Nietzsche is saying "I FOUND A KEY! Anyone care to try it in th

You don't. You try the key on the lock, and if it doesn't work you keep looking for another key. Nietzsche is saying "I FOUND A KEY! Anyone care to try it in their lock?" Eh, that might be a bit more euphemistic than I meant to be, but the point is there.