Dear EH-Listers, I have been following the exciting debate on "the history of error." My PhD dissertation is about a close subject, so I wanted to write down what I think about it. Here is how I understand the issue. 1. I personally think errors are not really important in our intellectual lives - they are not important insofar as we are not stuck with errors and their consequences. For errors are sometimes corrected. Academic journals, for instance, publish rejoinders, reminders, and commentaries. And there are long-lasting debates in sciences and philosophy, too. This, to my view, is a sign that we can achieve some "progress" in sciences and philosophy. In fact, we now can do open heart operations. We travel around the world in less than eighty days. Marginalist theory in economics found a solution to why diamonds are more expensive than water (the theory, of course, created other problems, but it is another story). In such cases, errors in their history don't really matter much. After all, if we are getting close to Truth, how can one call something a "mistake"? 2. But the situation is more difficult, I think, because we are not always on the path to Truth. In other words, we are not able to get rid of such errors and failure in the institutional evolution of sciences. One example is the "Coase Theorem" in economics: In the third addition of *The Theory of Price* George Stigler writes that "[t]he Coase theorem thus asserts that under perfect competition private and social costs will be equal. It is a more remarkable proposition to us older economists who have believed the opposite for a generation, than it will appear to the young reader who was never wrong, here" (Stigler, (1966) p.113). The quotation may seem bizarre to economists who have sincerely read Ronald Coase, especially his _The Nature of the Firm_ (1937). His point in the article was that we were not living in the best of possible worlds but in a world of transaction costs. Contrary to what Adam Smith said, Ronald Coase argued, we were living in a world where markets sometimes did not clear off therefore private and social costs would not be equal. The naming of the "Coase Theorem" was then basically wrong (for further argumentation, see an article by Deirdre McCloskey "Good Old Coase Theorem" 1997). In fact Ronald Coase raised the issue in _The Firm, the Market, and the Law_ (1988, p.15) and wrote that he actually argued the opposite. When this is the situation the undesirable consequences of such errors accumulate in an unusual manner - they accumulate in such a way that we cannot correct the errors and mistakes in the past. In other words, contributing to the literature of the Coase Theorem, we may be making it harder for ourselves to break free from the "once-secure path," so to speak. It is very "human all too human," as Nietzsche once said: we make mistakes. We sometimes correct them, but usually we cannot. I am sure in the history of science and economics there are more examples of error and mistakes which negatively affect the quality of our intellectual lives today. Therefore, they, in this respect, are existent and important. Thus we should teach the history of errors (or, we should be taught, I should say, as I am still a graduate student). 3. And there is one even more difficult and interesting issue: Sometimes we do everything correctly. We *optimize* while spending our money in supermarkets; we engineer bridges in the most *efficient* way. But we still have erroneous consequences in the end. This type of error occasionally appears unintentedly. That is to say, they are never anticipated. We take all the precautions in life to prevent bad consequences from happening, but still there may be things, consequently, making us unhappy. The Q-type keyboard is one example (see Paul David's "The Economics of QWERTY"). The design *was* actually a remedy to a problem. It *was* a smart design, it *was* efficient. But it was based on a problem (that is clashing and jamming of mechanical parts of keyboards) which we don't have in digital systems today. It now causes problems (at least David believes so). And Thorstein Veblen's "silly little bobtailed" wagons were also an "error" of the same kind. Van Vleck showed that British carriages were not economically *inefficient* or *irrational* but merely substitutes for more costly distribution and delivery means such as horses, hay and oats, trucks, and petroleum fuel. Small wagons were used because they suited to the existing infrastructure and not because they were economically at the margin (See Veblen in his Imperial Germany + Van Vleck, "Delivering coal by Road and Rail in Britain: The Efficiency of the 'Silly Little Bobtailed' Coal Wagons", Journal of Economic History, 57(1), 1997 JEH). Nevertheless it *was* an error simply because Britain wasn't at the forefronts of the industrial race anymore, and Germany took it over. The examples in this category are usually those which are produced by the theorists of path dependence and institutional economics. To conclude: Many economists are uncomfortable with what is happening in economics today because there are error and mistake in its institutional evolution. Some of them are correctable; some are not. Incorrectable errors and mistakes are important for various reasons. One reason is, as all the examples above point at, that we cannot have solutions to practical problems today and we think reason lies somewhere in history. Obviously the models of, say, rational choice and overlapping generations did not offer considerable insight, say, for the Oil conflict in Iraq and the past genocide in Rwanda. It lacks ethics; it lacks culture. No this and no that. I think we cannot prevent errors and mistakes from happening. They are in a sense inevitable because economics has become an institution itself, featuring path dependent properties, producing erroneous consequences. This is the reason, I think, we should be more knowledgeable about the history of error in economics. And finally not only errors in history matter. Wrong-headedness, whim, idiocy, irony, and so forth are important, too. That is to say, they all produce alike consequences... Regards, Altug Yalcintas