I was standing in a hall full of people who were listening to a speaker inveighing against synthetic a priori propositions. The atmosphere owed a lot to speeches by Hitler on the Jews and Joseph McCarthy on Communists: the speaker was standing behind one of those old-style microphones, shouting: We must root out synthetic a priori propositions! We must eliminate them! The crowd was getting increasingly worked up. I was standing by the wall, watching, feeling deeply uneasy.
Suddenly, I caught a glimpse of myself in a mirror. I was entirely featureless and flat and rectangular, sort of like a large stick of gray gum. And I realized: oh no, I am a synthetic a priori proposition! In the middle of this crowd of people who want to eliminate me! There was no way out of the hall that I could find, and in any case I didn't want to draw attention to myself, so I just huddled by the wall, terrified, hoping no one would notice that I was one of the very propositions they were so eager to eliminate. Eventually, I woke up in a cold sweat.
Mike Schilling comments:
First they came for the open sentences, and I didn't speak up because all of my variables were bound.
And then they came for the definite descriptions, and I didn't speak up because I wasn't the present King of France.
And then they came for the paradoxes, and I didn't speak up because I wasn't the set of all sets not members of themselves.
And then when they came for the synthetic a priori propositions, there were no premises left to argue for me.