the concept behind the book in the introduction: “the construction and payoff of jokes and the construction and payoff of philosophical concepts are made out of the same stuff. they tease the mind in the same ways…philosophy and jokes proceed from the same impulse: to confound our sense of the way things are, to flip our worlds upside down, and to ferret out hidden, often uncomfortable, truths about life. what the philosopher calls an insight, the gagster calls a zinger."