Jokes, aporia and undecidability

Derrida saw laughter as a version of aporia; and he linked aporia to an undecidability that he ties to fiction. I argue that such undecidability contributes to some jokes. Sometimes this undecidability enables the joke to combine plausibility and delightfulness. More interesting and more aporetic is the way that undecidability contributes to jokes that foreground their textual status (some meta-jokes for instance) and those that have an effect of unfathomability. The jokes considered include one on which Derrida commented and another which was told at his Columbia University memorial service.