Abstract
Perelman teaches us that, unlike demonstrations, arguments cannot be reduced to or understood as closed systems. In some particular--but telling-- ways, arguments are like jokes. Telling a joke requires close attention to, e.g., appropriateness as re gards subjects, length, the extent of shared knowledge of both particulars and stereotypes, and whether it is possible to be ironic without being misunderstood. Thinking along these lines points up the futil ity of reducing either the invention or the evaluation of arguments to formal schemata.