Wittgenstein imagined himself writing a philosophical treatise consisting of nothing but jokes. I suspect he was serious about the idea and the reason he never wrote it was because he lacked a sense of humor. In the same way that a sense of humor would be essential to writing a philosophical treatise consisting only of jokes, the lack of a sense of humor is essential to thinking that one would like to write such a treatise in the first place. What is either funny or scary about this — depending on your point of view — is that it is an instance of a very common scenario: doing, trying to do, thinking about doing, something for which we lack some essential capacity, and lacking this essential capacity is what inclines us to do, try to do, or think about doing it in the first place.
“The Case” – Available from Down Button

