Teaching the history of error is important because "error" is a historical category. Moreover, what today is considered an error might be tomorrow the source of innovative theoretical contributions. In art, this is quite clear. For instance, some paintings by late Tiziano were considered even unfinished at his time, but now they are masterpieces. This discussion is closely linked to the possibility of a discontinuous theoretical development, which I have studied in a paper ("An Example of Untranslatability") in "The European Journal of the History of Economic Thought" (2004). Miguel Angel Duran