It strikes me that I left something important out of a post I put up the other day, the one titled “Justified True Belief.” In it, I summarized Edmund L. Gettier’s 1963 article “Is Justified True Belief Knowledge?” an article that was less than three pages long to begin with, so it was a bit silly to summarize it.) Gettier cited a definition of knowledge as “justified true belief,” a definition that went back to Plato, and gave two examples of justified true beliefs that we should not call knowledge. Gettier’s examples were rather highly contrived, but have been followed by many publications giving more plausible scenarios in which a person might hold a justified true belief, and yet not be said to have knowledge. I said in the post that such “Gettier cases” occur in real life with some frequency, then gave a novel by Anthony Trollope as my closest approximation to real life.
Here’s something that happened to me. I was teaching a class about social life in ancient Greece and Rome. The topic for the day was marriage, including the custom of the dowry. Most of my students have passed their whole lives up to this point in the interior of the USA. To them the idea of a dowry is a bizarre one. To make it somewhat intelligible to them, I explain that in ancient times it was common for a household to subsist on resources approaching the minimum necessary for survival. So, it was quite a serious matter to share what little one had with one’s neighbors. Say a creek ran through your farm, and your neighbor wanted to make a deal with you to divert a portion of its water to irrigate his fields. If he were to trick you and take too much of the water, you and your entire family might very well starve to death as a result. How was it possible to develop such trust in one’s neighbor that it would be possible to strike such a bargain? If you and he were going to have grandchildren in common, then you could believe that he would have enough interest in your long-term well-being that he would be unlikely to treat with you in so harsh a manner. Thus, a property owner who would not let his neighbor dig an irrigation ditch for any amount of money might freely dig it for his neighbor himself as a dowry for his daughter.
I tell this story every semester. A couple of years ago, one of my students approached me after class. A woman from India, she was troubled by my explanation of the dowry, and by the textbook’s equally pragmatic discussion of it. Her parents had dowered her and her sisters, as her grandparents had dowered their mother, not with any such materialistic motives in mind, but as an expression of respect for the prospective bridegroom and welcome to his kinfolk into their family circle. She did not disagree with anything I had said; so far as she could see, all of my remarks about the economic function of the dowry were quite true. But she did not believe that any Indian, or anyone else from a society where the dowry was a living custom, would ever have made them. From her point of view, the propositions I had enunciated concerning the dowry were true, and I was justified in believing them. However, she clearly thought that I did not know what I was talking about.
I would make one other point. The vast and ever-growing literature that lays out plausible sounding Gettier cases makes it clear that the contrived nature of Gettier’s two examples bothers people. Yet, why do we have a category of “contrived” when it comes to counterexamples? Surely it is because we think that it is possible to think up some scenario in which a given statement might be true, even when that statement is not something we really know to be true. So that a far-fetched example may establish the logical possibility of a point, but only an argument grounded in real life or in exhaustive reasoning is likely to convince us that the statement is worth taking seriously and incorporating into that set of beliefs and mental habits that we consider to be our stock of knowledge. In other words, our very discomfort with Gettier’s examples proves the point that those examples are intended to establish.